August 1, 2017 – The Finishing Touch
I transferred the pickup from my old Gibson to the Sullivan a couple days ago. And after hours and days of practice and replaying this tune I wrote back in February as I started the project I got it to a good enough point to make it public.
I’ve listened to enough bluegrass to know the template and pattern of these songs by heart – simple and direct, not theoretical, while re-teaching the bible stories. The “rock” metaphor occurs frequently in the Old and New Testaments as well as the psalms. So I had lots of material.
Hope you enjoy hearing it as much as I do playing it.
Stand on That Rock – ©Larry Grauvogel, August 2017
June 2, 2017 – Really, Really Done
May 31, 2017
After playing it for about a week and thinking some more (no real rush here) I decided to go ahead and put in a new 5th-string nut, primarily to fill in the existing hole. It took me some time to locate a 1/8″ diameter plastic rod. I was able to drill out the wrongly set nut without damaging the fretboard (whew!). The only rod I could find instead of buying an already-made nut for $3 plus $7 shipping was white PTFE. I found it at Grainger Supply in South Bend for $1.60. I needed 3/4″ of the 12″ piece. I did cut a string groove in it so it actually helps hold the string horizontally and vertically. It fit snuggly into the existing hole so I didn’t glue it. Overall the 5th string now tunes up and stays in perfect pitch when hooked around the HO spikes at 7 or 9. That made me very happy.
May 20, 2017 – 5th-String Tuner and Pegs
To put in the dot at the 5th fret, which i wasn’t planning at first, I had to pull out the 5th string tuner. Since it did come out without too much effort I decided to drill in the dot. And I found that just pushing it back in wasn’t good enough because hammering in the HO spikes (explained below) just knocked it back out. So on-line i picked up this little press fit with a clamp trick.
Gorilla glue was my choice, being careful to wipe off any squeeze out – it wipes easily until it starts to set up. It ain’t comin’ out now!
I mentioned tuning the 5th string to the key of the song. Here is the trick – HO model railroad track spikes, yep. They have a square cross-section 1/32″ on each side, so a 1/32″ drill makes a slightly undersized hole for tapping them in. Again the hole only has to be about 5/16″ deep. I found that there were several ways to locate them so I went with what had worked for me before – right behind the fret and 1mm to either side of the string so as not to hit the vibrating string when not being used. One goes at the 7th fret and one at the 9th.
So one has to know that 95% of bluegrass banjo songs are in the key of C with the 5th string an octave G, the 5th note in the scale. To play one in D you just hook the 5th string at the 7th fret (octave A, 5th note in the scale) and for E at the 9th (octave B, 5th note in the scale). If someone is wild enough to play in F you can tune the string up one fret to an octave C from the 9th fret without breaking it.
This left the question of the 5th string nut to answer. Eric put the nut hole about 1/4″behind the 5th fret, with the string grounded on the fret. The other way to do it is to put the nut right behind the fret but elevate the string even with the other 4 strings and not use the fret at all. My problem was that when I put in the nut I tapped it in too deep. After weighing the pros and cons I decided to put an HO spike behind the 5th fret as my nut, which I did.
May 19, 2017 – Side Fret Dots
So the office is moved across the hall and my confidence is high so I decided that the time was right for drilling in the fret dots. I used my digital micrometer to center the dots in the frets, marking them with a 0.7mm drafting pencil, and eyeballed their vertical position. I set the drill depth at 1/4″. The only problem I had was with the vertical positions. In hindsight I could have mic’d the vertical positions as well – they are not precisely in line down the side of the neck, but only to the trained eye (mine). I marked frets 3, 5, 7, 10, 12 (the octave), 15, 17, 19 and 22, copying from my existing Gibson. There are different fret marking conventions but for bluegrass banjo this is the standard. By comparison my Martin guitars are marked at fret 9, not 10 and 21, not 22. For a banjo the G chord is played open. The 5th string is a drone, the idea taken from the dulcimer, and adjusted for the key that the song is written in. The dots are really only relative and used to keep track of where you are. The periodic 3-fret spacing is because there are no B#/Cb or E#/Fb in the chromatic scale. This means that there is only one fret between E-F and B-C, not the usual two frets for each key change
The octave 12th fret is marked with a double dot. The pictures show the sequence – drill, apply glue with toothpick (Gorilla glue) and wipe excess off, insert rod, snip it off. After that I scraped the rod to within 1/1000th using a single edged razor blade with cellophane tape guarding all but the 1/16″ of the dot – cellophane tape is 1/1000th inch thick. Then as you can see I used a small foam sanding block with P1000 followed by P2000 sandpaper and polished it out just like the lacquer. It was so good I didn’t have to put lacquer on the ends of the dots.
I had been planning to use foam sanding blocks behind the wet/dry sandpaper all along but only finally did it at this point. A StewMac video convinced me. I used the closed-cell foam that was part of the packing that the resonator came with 10 years ago plus some two-sided tape. It turns out that if you use your fingers alone or wrap the sandpaper around a block it always sands deeper at the edges. So I cut out and made a few different sizes of foam blocks for each grit. The one in the picture is 1″ by 2″, the smallest.
May 10 – New Packages on the Porch
Got my StewMAC package today with the fret side dot rods. Also I bought a fret dressing file and some finer sandpaper grades up to 2000-grit. And another quart of lacquer from Behlen came, for use on the guitar repair – another blog probably.
So I am working up to doing the work, but am distracted by moving my office across the hall as Matt Richard takes the final pieces of furniture. I will be repairing the drywall and painting the old office.
May 3 – And……Done – Well, almost
The treble D-string fill didn’t work the first time and the second time I realized that the binder plastic was not sticking to the nut material (it’s a different plastic altogether), so I just stuck the loose piece back into the slot and it worked well enough. It will be super glue in a bit.
So I’ve started playing again, and that’s when I noticed that I hadn’t put the fret dots in the top binding of the neck. This is how you keep track of where you are playing – there is a dot (black on a white binding) at frets 3, 5, 7, 10, 12 double dot, 15, 17 ,19 and 22 double dot, these correspond to the intervals between the notes on the scale. So back to Google to see how this is done, and to StewMAC.com for the 1/16″ diameter plastic rod that is used. Measure the center of the appropriate fret with a micrometer, mark with a center punch on the top neck binding and carefully drill a 1/4″deep 1/16″ hole, put in a bit of glue, jam in the rod, clip it off, sand it down and drop fill it over. Normally this is done before the lacquering but I forgot, so I’ll be filling it over as part of the sanding and polishing.
The 4th fret appears to be a bit high compared to the 3rd and 5th so it may need some filing down. Then I learned on-line that one of the neck finishing steps is leveling the frets with a filing block. That I can do, but I’ll need a fret dressing file.
And in the bright light I had trained on the instrument during this exploration I noticed a couple more flaws in the resonator that will need attention. I think the drop fills are not sticking in the grooves along the binding because of my not cleaning off the Meguires polishing compounds. So I will be using some mineral spirits and scuffing down in the small grooves before I drop fill again. I am finding this fascinating as much as it is challenging.
May 2 – The Home Stretch
Yesterday I sanded, polished and buffed out the wood rim area that is visible below the tone ring, the area that I had resprayed a couple days ago. It is shiny but not perfect since some of the stain I used to color the area got sanded down and there was some residual graininess, but with the J-hooks and arm rest in the way not much shows anyway. As I am learning in my latter years perfection is relative. And so with that I was able to re-assemble the pot, this time for real as I tightened down the head and attached the modified tailpiece and arm rest. And since the neck was done I attached the neck to the rim. Here it is at that point:
Meanwhile back on the resonator I was finding a second group of more minor flaws along the lower binding on the sides. It has taken me another three cycles of “drop-fill with the syringe-allow to dry overnight-sand and polish” to get it where I want it. And fortunately the finish is thick enough that I haven’t sanded through, knock on wood! So this is the remaining piece of the puzzle.
As you may have noticed in the picture there are strings on the neck – oh, yeah. Last night I cut in the string grooves. They are spaced 7.5 mm apart with 4 mm on each edge, as measured from my existing Gibson. The string spacing at the bridge is 11 mm on the J.D. Crowe bridge from Sullivan’s. And with these measurements the 5th string is 7.5 mm from the bass D (4th) string, just as it should be. So careful measurement, and re-measurement paid off. I used an assortment of my fine saws to cut the slots to as close to the string diameters as I could – a 42 tpi (0.017″) and 48 tpi (0.014″) hobby saw and my Bear saw (0.023″). So things were rolling right along until I got carried away with the treble (1st) D-string and cut it too deep so that it was resting on the first fret. Dang, but I had anticipated just such a problem and my research indicated that I could soften a piece of binding into a paste by soaking it in acetone to use as a filler, which is what I did and am currently waiting on to harden. It will take a few hours. Here I am putting in the filler: I put my halogen lamp on it to speed up the process, protecting the surrounding areas with thick towels.
But in the meantime I tuned up the other strings and actually played a few licks. That was an exciting moment. It actually works.
When the last drop fill sets up on the resonator here in a bit I should have it sanded, polished and buffed soon thereafter, with only this string slot to touch up before it’s finished and ready to play.
Now back to the resonator. The drop filling of the binding groove has been tedious. I needed three fills with overnight to dry between each to be sure. During the process I did improve my drop-fill technique – I upgraded from a toothpick to a syringe, which proved to be way more precise and with less risk of a stray drip in the wrong place. But just as I reached the end some lacquer leaked under a piece of masking I was using just to mark the general location on the rim (the last area needing the fill was actually hard to find except in certain light) and the tape pulled of a small spot of finish. So back at it. But the resonator is now only a touch-up away from done. The wood rim sits by curing, waiting for its final polishing. So it is coming together.
Next challenge – cutting the string slots in the nut and setting the string height (aka “the string action”).
April 27 – Finishing the Neck – One down, Two to go
With the headpiece cured for 3 days I was back on it and this time the results were as near to perfect as I can get. I learned that as the scratches are taken out reducing the hand pressure is key to getting the last minor swirls out with each successively finer abrasive. It’s all in the wrist so to speak.
With the polishing done I had to ream out the tuner holes to remove the lacquer build-up so that the tuners would fit again. I had the presence of mind to start from the back of the headpiece. I used the same Tinker Toy rod and 80-grit sandpaper successfully, but with some minor chipping that will be covered up by the tuner. In this process I put some scratches in the front, so once the tuners were fitted I removed them, re-polished the front and very carefully re-installed them. Then I drove the 5th string tuner into its hole down the neck.
And here it is, ready to put on the strings after I cut in the string slots. The finished headpiece says it all.
April 24 – Q-Tips and Toothpicks
Re-sanded and polished out the neck using Eric Sullivan’s technique with very good rersults. Closer to Eric’s finish but not all the way there. So I moved on to the front of the headpiece and things were looking good until I broke through the finish in one small spot. So I scuffed it up and put on 5 more coats today. It has leveled out nicely so I assume that on Wednesday or Thursday I’ll be able to finish polishing out the entire neck.
I took the flange and the brackets off of the wood rim and lit into it with the new polishing protocol. The only area that shows outside the instrument is the 1/2″ band between the flange and the head, and it had some residual pitting. I went through the finish in one small spot with this as well, taking some of the walnut stain with it, but the fix is different – a Q-Tip and a toothpick. I went ahead and finished polishing out the rest of the rim with excellent results.
I did a drop fill with the lacquer for the first coat on the sanded through area, sanded it down after an hour and then applied some stain with the Q-Tip. When that had dried I put a second drop fill of lacquer over the stain. Tomorrow I’ll sand and polish it out and that should complete the wood rim.
And then on to the resonator, which was polished out pretty well already, but had a basic graininess in the background that just wouldn’t make the quality control review. So I started by taking off the grainy-look with 1000-grit wet/dry paper and mineral spirits. In the process I discovered that some of the imperfections along the seam of the top binding on the side were actually a gap between the binding and its groove from when I first glued in the binding. I was able to sand out all the other glitches. So then it was back to the toothpick to drop fill the gap. It looks like I will need only two coats. But the great news was that the back of the resonator polished up better than it was when I started on it today and I will not need to re-spray it.
April 21 – Taking a Step Back
I talked to Eric Sullivan about the tail piece and his final finishing techniques.
For the Presto tailpiece he said he just leaves it unfastened to the tension ring and the strings themselves hold it in place. It comes with a small screw that is used to rest against the tone ring to adjust the tailpiece angle, but he said he takes that off and it is unnecessary. As a player, however, it is enough aggravation changing the strings (they have looped ends that need to be hooked over the prongs of the tailpiece) without having it falling off or moving around, so I came up with a bracket to fasten the tailpiece to the J-hooks just like the armrest using the small screw. Yea, its carbon steel and not chrome plated and sprayed satin black, but it is mostly hidden under the tailpiece and below the tension ring, so its effect is similar to the resonator brackets that I painted the same color. Here’s a picture of it. At least it is engineeringly very functional if not real pretty.
My step back is on the final finishing. I learned three things from Eric – use a flexible sanding block behind the very fine sandpaper and polishing compounds to level the underlying finish, use 1000-grit paper to level initially, and follow this with Meguiars 21 and Meguiars 2. He doesn’t do the 1:1 dilution final coat, just builds up a good thick layer of lacquer as smooth as he can get it to start from. He lays down 3-4 coats, scuffing with 320-grit between each, then sands it down and repeats another 3-4 coats for his base.
So since I am on the neck currently and had sanded through in a couple small spots, I stepped back and put on another 3 coats. That was 3 days ago. I will see how the 1000-grit followed with Meguiars 21 and 2 works, and if it does I’ve decided to start back on the resonator, which I can see will not be as good as Eric’s the way it sits right now, with the 1000-grit. If I sand through then it will be step back again and add more layers.
To get my mind off of this endless painting, I took some time while the neck finish was hardening to install a dedicated 4″ exhaust duct for the paint booth. That was challenging but as of last night it is in and functional. So there is no longer a need to disconnect then reconnect the booth when Mary Ann uses the dryer. After building the Lodge last summer I am very good at removing and re-installing vinyl siding to cut in vents and their covers.
April 16 – 17: Easter Weekend
So in the midst of the Easter celebration I managed to finish the following:
- final painting of resonator interior- CHECK
- decide how to finish the adjusted resonator brackets and finish them – CHECK
- glue in the resonator lugs – CHECK – Gorilla Superglue
- polish out the resonator exterior – CHECK
- install the control rods – CHECK
- assemble the wood rim and flange with rersonator brackets – CHECK
- assemble the rest of the pot – tone ring, head, head ring and tailpiece – CHECK
So what’s left to do now?
- touch-up the neck & finish polishing it – in process
- improve polishing of resonator and neck
- install the arm rest
- attach the neck to rods – rods in; neck in process
- install the string machines (tuners)
- install the tailpiece – got a problem here, it doesn’t fit so need a different one
- cut the string grooves into the fretboard nut
- install the strings and bridge; adjust the neck angle, bridge position and string action
- tune’er up and play
The next big challenge will be to finish the repainting of the neck and then bring the polishing and buffing up another notch. After that it is all downhill once I get a different tailpiece that fits. These will require another call to the expert.
April 13 – Here We Go with Assembly
Putting Together the Pot Assembly
In the background of these assembly steps I was working on touching up the interior of the resonator. I had to remove the lugs after checking their fit with the flange and rim. They were perfect. The notches got stained ebony and the upper rim after sanding got a color coat of walnut stain prior to a lacquer overcoat. I also sanded out the inside bottom to make it look more finished prior to the final overcoat. Then I polished it out a bit to even it up.
Here is a series of pictures illustrating the assembling of the pot
I was wondering where some deeper scratches were coming from as I worked down to the lesser grit polishes. And I guessed it was the foam applicator pads, so I switched to using one of our remaining 100% cotton diapers – and bingo the polishing jumped up to a new level. Yowza! So I ordered some new cotton diapers on Amazon for future use.
But then a setback just as I was winding up on the neck – I polished right through a small spot in the finish along the fretboard binding. Crap! I had two choices – the old “drop-fill” trick or respray the entire back of the neck. A pretty easy first choice, and the drop-fill worked. A bit of sanding and blending to do but less work than a full respray. It took three coats to fill it in thick enough.
April 11 – Coming Up for Air
Jump ahead to Tuesday and here is a shot of the stained, primed and lacquered resonator interior taken in the afternoon when fully dried overnight. It looks good but a little more glossy than I was expecting.
But the resonator is now done except for polishing and buffing. I was very happy that there was no bleeding of the stain and resonator interior lacquer on to the upper rim where I had masked it off.
A tense moment occurred when I started peeling off the masking tape from the resonator and realized it was really stuck to the finish. I could just see it lifting off my near perfect finish like with the headpiece. I took my time and the finish was unaffected. I used some mineral spirits to clean off the adhesive residue from the tape. So looks like I bonded the multiple coats of lacquer together and the primer is performing as advertised.
In between painting the interior of the resonator I laid into polishing the wood rim. Of the three wood parts this has the worst final coat because it was always the first test of my spraying ability. It’s not bad, just not as good as the front of the headpiece, which by the way is even better than the outside of the resonator. So the polishing is three steps with increasingly less abrasive liquid polishes. The first is a Luthiers Mercantile special blend, the second is a Meguiars Plastic Cleaner and the third is a Meguiars Plastic Polish (I guess I could have bought these last two at Auto Zone had I known – these are a very common brand of car care products). It was going well enough, but the finish was pretty “sandy” to start with. I had the thought – what if I start with 800-grit sandpaper, maybe that will speed things up. Well, not only did it speed it up but the final surface reflects my project light bulb like glass. Whoa, this is working, and on the worst of the three pieces. Now I am getting excited to see the end product.
While watching the paint dry till tomorrow I have an opening to install the lugs and brackets on the inside of the resonator and on the wood rim for attaching them together. Nothing to do till tomorrow but watch the paint dry. After that comes polishing the resonator.
Starting the Assembly
The most tense assembly task I think is drilling the holes from the inside of the resonator for its brackets to half its thickness. So why not start with that. I’ve done this once about 10 years ago for my Gibson but don’t remember how I kept from drilling all the way through. The screws are small so maybe I just need a shallow starter hole. I normally use a piece of tape on the drill bit to mark the depth, but a mistake here would be catastrophic. The available drill depth guides go down to 1/4″. The drill will be 5/32″ so this guide should work. The resonator side is about 1/2″ thick and the anchor screw is 1/4″ long, not a lot of room for error.
Another problem that Eric Sullivan made me aware of is that the resonator brackets that attach to the rim are too long for the wood rim and resonator combination. They are 1-1/4″ long for a 1″ space. Eric cuts off the ends. Larry G chisels out a shallow 1/16″ slot in each of the four locations so that the flange sits down on the edge of the resonator rim.
So I have a plan. I have the depth guides. Now to get to work.
April 10 – Maybe Getting the Hang of It Finally
Last night I stained the inside of the resonator ebony. It is black but the grain shows through. I’m not sure but i think the wood is regular maple, instead of the curly maple on the outside. Used the spray can to put down the primer and when that dried I added some more stain around the edges to blend in the color .
I let the neck sit overnight after its last thin coat that didn’t lay down as smooth as I expected. I think that was because I only let the previous coat dry an hour or so, then sanded and resprayed. Each successive layer softens the ones under it, which must in turn affect how it dries. That theory was just proved out when I resprayed the front of the headpiece and it is laying down like glass, just like the resonator. Cool.
April 9 –
3rd, ah 4th, ah 5th Time’s the Charm – Yes!
I am going crackers over the final finishing, but that’s nothing new. Even with prayer I can’t bring myself to stop spraying before the finish runs. So it’s wait an hour, sand out the sag, re-spray, wait an hour, sand out the sag and repeat. Finally this afternoon I found the forbearance to stop the spray in time and got a near perfect resonator, ready for final polishing and buffing – whew!
Thought I had the neck done last night until I took off the masking in the rod nut and pulled some finish off. Well that took another three thin coats to blend in. The final coat is good but not as glassy as the resonator, so I’ll let it dry over night and try another in the morning.
There is a two day wait between the final coat and polishing/buffing. The rim will be ready on Tuesday April 11, the resonator on Wednesday and the neck on Thursday. I’m getting there.
While waiting I’ll be finishing the inside of the resonator ebony black tonight. Mask it off, stain, let it dry overnight to be sure and spray a primer and one topcoat. Simple enough.
April 6 – Drop Fill Magic and Color Fills
The drop filling on the resonator and back of the headpiece took two treatments but worked as advertised. The nick in the veneer on the front of the headstock was a bit more challenging. I tried making my own wood filler with some walnut sanding dust stained ebony black and mixed with some lacquer, but it didn’t work as I expected. However, two drop fills along the seam with the fretboard nut did the trick.
This spot sanding produced some lighter spots that I thought I should touch-up. It seems that the lacquer dissolves the stain up from the wood and then sanding it thinner makes it lighter. So I finally found my Q-tips and got the lines and thickness of the stain the way I wanted it. Need to allow the stain to dry before overcoating. It is not really soaking into the underlying lacquer but with the next coat, which softens the underlying layers, it will be incorporated into the finish.
Time for the 5th & 6th & 7th(?) Coats
Received the second quart of Behlen lacquer, their thinner and my 3-step buffing/polishing liquids yesterday, so things are in place to push to the finish. Almost a banjo! I have some concerns on the thickness of the lacquer at the start since I am using the remainder of the 1st quart that will need some thinning. But if I thin it and spray some scrap, I will not have that much left for real use. Hmmm. Best choice is to thin what’s left and add in some new,then spray the scrap to check.
Well, I actually put the last 6 oz of the first quart into the cup, then got cold feet and added 2 tsp of thinner and then topped it with the fresh stuff. Didn’t do a scrap piece but went right at the wood rim and it laid down beautifully. I got all excited and forgot to filter the lacquer into the cup, but apparently there were no globs in it and the gun worked without a hitch. I then figured that I had been wet sanding between each coat, more than scuffing, and so a 6th full coat was in order before the 1:1 final. With the 6th coat on the resonator I can almost use it to shave by, before buffing and polishing. Pinch me, is this really happening? It’s all in the preparation.
The wood rim is ready for its final 1:1 coat. The neck, especially the front of the headpiece needs a thicker finish. I sanded it down pretty far at the nut while filling the chip there. So I’ll wait overnight and put another full coat on it.
Inside of the Resonator
The resonator Eric Sullivan made for my Gibson banjo is finished with a flat black interior., except for the top lip. You don’t see this area unless you look through the cutouts in the flange, so any dark, flat color will work. My resonator lip matches the dark walnut side.
Time to check back with the expert for how he does this. As friendly as ever, we talked for 15-20 minutes. In the end what I learned was that he uses a couple coats of lacquer over a dark mahogany water-based stain. So it’s not a flat black sprayed enamel like I thought. So I plan to use my ebony black stain with the lacquer primer and a topcoat.
Hurry Up and Wait
Now it’s time to watch the paint dry for awhile. While I was waiting here is an improvement I made – a stand to hold the spray gun while filling. Just a hunk of 2×4 with a couple angled holes to match the bottom of the gun. Definitely helpful already.
I put a 6th coat on the neck after sanding down with 400-grit and on drying it is much improved. I am going to sand down the drop fill at the chip at the nut and the rest of the neck and then shot on the final 1:1 coat tomorrow.
I shot the final 1:1 coat on the rim this afternoon and it is ready buff and polish, but gotta wait 48 hours. Shot the final 1:1 coat on the resonator after sanding it out and rats – got several sags. I got carried away. The lacquer dries slower when thinned and I assumed it dried faster – ooopsie. How bad the sags are will be obvious in the morning as drying continues. They have been shrinking slowly all evening so maybe not too bad. I’ll have to back up, sand them out when good and dry and then shot another 1:1 coat, thinner this time, on it. But where there is no sag the finish is really incredibly glossy. And I thought it was glossy before. Man. So I am impatiently hopeful waiting to correct the sags.
April 5 – Time for Flaw Control
With scuffing and painting the same surfaces multiple times you find all the imperfections and the skill is in dealing with them. And the imperfections are not all of my doing.
In particular the ebony veneer on the headpiece has a small chip in its edge right along the nut (the top of the fretboard where the string grooves are). After 4 coats there is still a depression, so I plan to “drop fill” it with lacquer – put a drop on it from the end of a toothpick, let it dry, sand and repeat until level. This chip came from Eric Sullivan – small but obvious to me now. A second flaw, well not really a flaw, is the obvious differences in grain lines on either edge of the back of the headpiece from the glue-up of the original wood. I did my best to match the stain color and hand paint in a different grain, and while doing this I sanded a shallow depression above the top tuning machine on each side. The glue lines are much less noticeable now that the finish is thickening up but these depressions are more obvious. I am planning the same “drop-fill” with these. The third flaw is a small area on the back of the headpiece where I sanded some of the stain out – I am going to try to put some stain in between the remaining coats of lacquer And lastly in my messing with trying to hide the joints of the resonator purfling I created two very small depressions that are visible in the mirror-like gloss, and so again a drop-fill will likely work.
This will give me something to do while waiting for my re-supply of lacquer and thinner.
April 4 -Back At It with 3rd & 4th Coats
April 3 was do income taxes day. That ended very well and so my ego was rebuilt enough to challenge the lacquer once again.
Today I started by Googling “proper air pressure for an HVLP spray gun” and ended up at the Eastwood Company site and a YouTube video. Perfect. Turns out the recommendations are to run the pressure at 25-30 psi (hence the “low pressure” in the name) and have the pattern in a full fan shape with the paint valve all the way open. Shoot, I didn’t even know I could adjust the paint feed until I looked more closely at my gun to see how the trigger adjusted. So these corrections took maybe 2 minutes max.
Trusting little to luck I dropped back to my scrap wood and laid another coat on it, primarily to check out the effect of the 10% thinning but also the new spray gun settings. Perfect. So then back to the wood rim. Laid a nice wet coat on it after scuffing and aside from putting my fat finger right on the exposed ring when still wet it was a big improvement. A thicker coat that didn’t sag and really leveled out to a high gloss. Then the neck, and again a great result. Then the resonator with the same non-sag, very high gloss endpoint. What a relief. I am considering that this is the 3rd coat on the resonator allowing for sanding out the orange peel, so two more to go. I can see that with the 3-step polishing ang buffing I am going to get to that mirror finish I want. Now I just need to wait for another quart of lacquer to arrive from Amazon to complete the 5 coats plus top thin finish coat. My research indicates that CF Martin Guitars aims for a 6 mil finish. Any thicker and it tends to chip at the edges too easily and is more likely to crack. So 6 coats but not too thick in total.
April 2 – Learning Curve
Well it was bound to happen. I am not a very experienced lacquer sprayer. Heck this is my first time! So what happened was that after I got down to the last 1/3 of the quart of lacquer I had just put the third coat on the neck and rim and decided to catch the resonator up to the third also. I was spraying at 40 psi as before but I could tell the fresh surface wasn’t leveling out like it should. I finished the coat and after 30 minutes it was clear that I had a case of “orange peel” – when dry the surface is still rough like an orange. The primary cause from consulting my problems website was not enough solvent, so that the solvent evaporates too quickly to allow the leveling before the lacquer reacts and begins to set up. Secondly, too much air pressure, and I realized I never really researched how to set up an HVLP gun. So this cost me a bunch of 400-grit sanding time to get the orange peel into manageable shape for the next coat and some gyrations for thinning what finish was left in the can. The troubleshooter recommended thinning the lacquer not more than 25%; I decided on 10-15%. The quart can had 1-1/4″ left in it and full was about 4-1/4″; this ratio times 32 ounces in a quart gave me the remaining finish amount (about 10 ounces) and 10% is of course 1 oz and every good cook knows that there are 16 Tbs in an 8 oz cup, 4 cups in a quart and 3 tsp per Tbs. So a tsp is 1/6 oz. For the record a 2 tsp polyethylene cough syrup dosing cup is insoluble in acetone (the primary lacquer thinner component) and works perfectly for adding 6 tsp of thinner. By this time I was pretty torqued up with anxiety and so decided to let it sit for awhile.
March 31 – First Two Coats
As I said above I decided to start with a piece of scrap wood to work out the details of the spraying. The primer is in a spray (“rattle”) can. This went without incident and so I went on to the finish spraying. I settled on 45psi and a rounded vertical pattern with the undiluted lacquer. I got a bit carried away with the second test coat and had a sag but this leveled out nicely went dried.
So collecting my thoughts and taking a deep breath I launched into the wood rim, the least visible of the three finished parts. The primer was easy so I went ahead and put two coats on each of the three parts with scuffing using 320-grit paper in between. Now for the first coat of finish. The wood rim developed two small runs on the outside that were easily sanded out between coats. The neck turned out to be easiest because all it took was a 180° rotation to get at all the facets. I got carried away with the resonator, mostly because it was hard to see how much liquid had been supplied and how it will level. Two sags developed toward the outer rim but there were no runs down the sides. Exercising great restraint I allowed the lacquer to dry longer and as I hoped these leveled out with only minor unevenness. I will be able to sand these out between coats after allowing extra drying time.
So here they are after two coats, drying for the next coat. The full effect is of course hard to see in the pictures. Lacquer is a new experience. The drying times are nearly instantaneous compared to enamel and urethane. They are dry to the touch in 5-10 minutes and only an hour is needed before sanding between coats. This eliminates nearly all of the dirt and dust in the surface, especially with the filtered spray booth air.
So I am excited. It is apparent that with some precision care the mirror finish is definitely within my reach. Looking ahead the lacquering will go something like this:
- remove imperfections out of 2nd coat and scuff with 400-grit
- apply 3rd coat, wait 1 hour
- remove imperfections (hopefully none by now) and scuff with 400-grit
- repeat for 4th and 5th coats
- wait 2 days, then scuff with 400-grit
- apply 1:1 dilution final coat; wait 3 more days
- proceed to buffing and polishing
I have found that wetting the wet/dry sandpaper with mineral spirits works really well and without water-on-wood risks, so I plan to do the scuffing wet throughout this process. I have 600 and 800-grit paper and am wondering why I can’t use them instead of 400-grit. Behlen only calls for 360-grit.
March 30- Let the Spraying Begin
The lead-in to the beginning of the lacquer spraying has been very tense because it may become obvious very early on that I will not be able to attain the mirror finish on the rim, neck and resonator, and if so then the project will be a bust. I’ve done everything I can think of to prepare – the mini paint booth with filtered inlet air, an HVLP spray gun, filtered and dried compressed air, the best lacquer matched with its special vinyl primer and a bunch of web research and reading on how it’s done. Got some very good information from www.frets.com and www.lmii.com (Luthiers Mercantile International Inc.).
The best info on finishing came from the Behlen Lacquer can. Five coats with scuffing in between each with 360 to 400-grit paper. The last coat will be a 1:1 lacquer dilution after sanding out with 400-grit paper wetted with mineral spirits, followed by buffing and polishing. I learned that sandpaper comes in grits down to 12,000 for final polishing. Wow, and I thought 600-grit was fine. But I decided to go with a 3-step liquid buffing and polishing finish instead of using the really fine grit sandpaper. Eric Sullivan told me to use the back of a piece of closed cell foam floor pad, like from my Craftsman mats around the worktable. Instead I found buffing and polishing foam pads at Harbor Freight used for auto finishes. These will be a backup to the liquid system, or maybe what I use to apply them.
Masking Off – Ugh!
Next was the tedium of masking off the pieces. However, good masking is crucial to the end product. I’ve been using Frog tape since if you believe their advertising the finish is less likely to bleed under it. You’ve probably noticed the green Frog tape on the portion of the wood rim that is to remain unpainted. The inside of the resonator below where the flange will sit will get a flat back sealing coat since it is not visible when assembled, and because that is the way Eric Sullivan does it. But the top edge and rim above the flange will be lacquered. So my choice was to do the lacquer first and the flat black last. I masked along the inside edge of the flange lip and used a round of kraft paper to protect the rest of the inside.
The fretboard and top of its binding also do not get lacquered. I double checked the top of the binding on my guitars to make sure of the latter. This masking was a bit trickier because the frets are in the way of a good edge seal and because the ends of the frets also do not get lacquered. So I carefully used a putty knife toi seal the tape against each side of each fret. Then I put a length of the Frog tape on the exposed sticky side of this to make a sort of flap. Then I covered the remaining gap over the fretboard. If you are wondering, the fretboard gets a hand wiped finish of boiled linseed oil eventually to keep it from drying out and cracking.
March 20 – Cutting in the Neck Slot
Before I can paint the resonator I need to cut in the slot to accept the neck. This is precise work for which I’ll use my fine toothed Bear saw. I have a pattern for the heel of the neck that passes through the resonator as a guide and my other banjo for a reference. Once it is rough cut I’ll shape it with a sanding block and then dress it out. After the painting the edge of the opening gets lined with felt – I am undecided whether it will be red, green or black. The inside of the resonator will get sprayed flat black to produce a shadow box effect behind the flange when all is assembled. I’ll mask off the back of the neck slot to kept the clear lacquer out of the inside as much as I can.
So after a second to collect my wits I made the measurements for its depth very carefully by assembling the neck with the wood rim and flange – 30mm – and drew it on to the resonator and the centered the heel pattern on the binding lap joint, which will be cut out, and used a square to draw the vertical sides. As it turns out the heel is slightly trapezoidal, wider at the top than at the bottom, but this will be part of the dressing out to get the fit precise. After rechecking the measurements and guide lines, and a short prayer, I put the Bear saw to the top binding and pulled back and was into it. As shown by the pictures it went well and actually fits together. I decided to go with the green felt because the inside of the case is green. It turned out very well.
So now onto the spray painting. First step disassemble, clean and re-assemble the new HVLP spray gun. This was simple enough.
Next step is to practice using the spray booth with the spray can of Belden lacquer primer I bought – they highly recommended using it as did the best review I read – on some scrap wood. This seems straight forward enough. Next sand the bindings clean with 600 grit sandpaper on both pieces. Now wipe each down with a tack rag, fire up the glovebox and apply the primer.
Next, mess around with the air pressure settings and dilution of the lacquer on some scrap wood to get the gun to lay down a nice glass-like coating.
March 19 – Getting Ready to Spray Lacquer
I picked up a combination pressure regulator and water/dirt/oil filter at Harbor Freight. I needed to do some re-plumbing of my compressed airline in the shop to install it. Turned out that I had all the fittings and 1/2″ pipe that I needed. This took most of a morning but PVC solvent welded piping is something I have done a bunch of so it went without a hitch. Here it is:
Next, since this is lacquer the solvent is much more potent than for a urethane or enamel, so the paint booth needs to be exhausted outside. Scrounging around I decided to put a tee connection in the dryer exhaust duct that runs directly over the worktable in the shop and a check valve in the duct ahead of it to keep the fumes from blowing back into the house. Also the dryer will not be available while I am painting since the duct will be blocked to it. So here are the tee and check valve (a winter/summer dryer diverter box installed backwards) in the line. This part of the work was a pain for about another half a day.
The third piece took an entire Saturday – the mini spray booth. Actually it is a glove box. The finished size is a bit smaller than my initial thought at 36″x48″x 34″ tall with a furnace filter on the intake, a lesser quality furnace filter in front of the exhaust fan to protect it from overspray and a flex duct connection to the dryer exhaust tee. The cardboard transition cone from the 9-1/2″ fan to the 4″ flex duct called into action all my sheet metal drafting experience and a bit of geometry. I turned on the fan and it actually works, although radial fans
cannot handle much back pressure, do the airflow is lower than I would like. But it is pulling air through the glovebox and exhausting it to the outside. Here it is. I still need to put the arms with attached gloves in and install the window glass so I can see clearly through the heavy visqueen.
I bought Belden nitro-cellulose lacquer with its recommended primer through Amazon prime. After reading the ratings this was the best stuff around,as long as you know how to set up the spray gun and have your air dried and filtered.
I bought a gravity feed air-assisted (HVLP) spray gun at Harbor Freight. I also found a website that discussed spray finish quality problems and how to correct them that is very helpful. Another piece of good news was that I was able to return my purchases connected with the no longer needed hide gluing and use the money for the paint spraying equipment. Here is the final glovebox arrangement with the arms, HVLP spray gun and lazy susan ready to paint, shot from the opposite side where the pieces will be put in and then sealed closed. Since it’s only temporary I decided to skip doors and just tape and un-tape the inlet filter to put the pieces in and take them out. The Gorilla tape makes a great hinge along the top.
March 14 – Need a Paint Spray Booth
It occurred to me now that what I have remaining on the project is wood finishing. So to keep the dirt and dust out of the finish I’ll need a mini paint spray booth. I have built a temporary spray booth before when I refinished 10-Speed bikes for the girls, so I have a mental picture of what I am after here, but this will need to be cleaner. I saw what Elon Martin used, the Amish tablemaker who did our round oak kitchen table) – basically a large closet with fiberglass filters in the double door opening and an exhaust fan in the opposite wall. Mine will be 4’x4’x3′ high with plywood ends, 6 mil visqueen (heavy polyethylene sheeting) on the sides and top, plus a glass window (old picture frame glass) for seeing the work. Inlet air will be filtered through a very high efficiency furnace filter that I salvaged from the new furnace because it didn’t work well for it, and the booth will be exhausted with one of our box fans after passing through a standard furnace filer to protect it from overspray. I have a lazy susan turntable for placing the parts on for rotating (the resonator is after all round). I am planning to make this a glovebox arrangement using the arms from a leftover Tyvek asbestos protective coverall (I am retired now) and a pair of kitchen gloves so that I can keep the space isolated from the rest of the shop.. And of course copious amounts of duct tape.
In the back of my mind – where to get the lacquer, how much to thin it and what pressure setting on the ‘ol spray gun to use? Here we go!
March 13 – A Course Correction
After re-sanding and re-staining the center circle of the resonator, and still not being satisfied I worked up the humility to call the expert Eric Sullivan. I have his cell phone number and caught him at his workbench. After he turned off some equipment so he could hear me we had a long conversation on how to handle woodgrain and finishing problems. His quote for the day, delivered with that Southern drawl that I love to imitate, “Don’t trust what you see under any clear finish”. He then talked to me about adding color between coats to even out staining and even painting in grain lines by hand. I asked him what finish he uses and he replied nitro-cellulose lacquer. I was planning to use gloss urethane, which has more color than lacquer. Hmmm. But I was inspired by the conversation and went back at it – re-sanded a third time and worked out the aforementioned tear-outs, then blended the staining back in. I also cut out the misaligned piece of binding and patched in the another piece. This time both were near perfect and much improved. Ready for finishing. Well, I want to try another trick on hiding the binding seams and then need to clean smidgens of stain off of the bindings.
I then mentioned that I was getting ready to glue the tone ring to the wood rim. He said, “Oh my, don’t do that! It really messes up the tone. You want a tight slip fit (which is what he machined into the wood rim for me), and don’t put any finish under the ring ’cause it’ll be too tight.” So whoa, that saved a BIG mistake, saved me some work and answered my question about finishing the wood rim. Now if I can return my hide glue pot and accessories for credit that will be a big plus.
March 10 – Setbacks
I have a problem sometimes with getting too meticulous and not considering bad outcomes to some attempts to make things “perfect”. Two things happened with the resonator:
- as you can see above the staining job was near perfect; however I noticed some “tear-outs” in the grain of the center circle; I set out to sand these out then realized that this end grain was what it was going to be no matter what I do; now I am faced with different depths of stain that will necessitate sanding out the entire circle and re-staining to blend it in. I need to come up with a way to fill these tear-outs so that they take the stain to match the surrounding grain, too.
- there was a 1/16″ gap in the inside circle’s binding that I attempted to fill with a small piece of binding; this went well except that the black rib in the middle of small insert piece is at an angle to the rest of the binding; the jog in the alignment is too noticeable. So now after I’ve already welded this 1/16″ piece in with acetone, I will need to cut it out and do it again (the way you glue on bindings is by injecting a tad of acetone with a syringe between the binding and the wood and then pressing it against the wood until the acetone dries).
March 9 – The Desired Effect
The resonator was another major challenge to “color inside the lines” with the contrasting stains. This is why I went to kindergarten and maybe 1st grade, to get good at staying inside the lines. Again I used the small brushes.
The neck is made of the same curly maple as the resonator, but is a glued-up solid piece and not a veneer. By its nature the neck has end grain exposed at the heel and tuner headpiece. In the first staining this end grain took the stain much darker than the rest and I didn’t like the overall look. So I took to it with sandpaper and steel wool to work back down to the bare wood and re-stain it. This worked better than I expected, and with a thinner coat of the dark walnut stain applied with a rag and not a brush I got the blending I was looking for, as you can see. The “curly maple” gives it the cross stripes visible in the picture. The wood grain actually runs in the long dimension. The maple’s “curliness” is very visible in the picture of the resonator above, in the lighter center circle.
The glue pot arrived yesterday so I am preparing for gluing the tone ring to the wood rim. The question is whether I should glue the ring on and then varnish the rim with the ring masked off or varnish the rim and then do the gluing. The two considerations are 1) whether it’s OK to leave the wood rim under the perforated tone ring unfinished where there is no hide glue, or 2) better to finish the rim but leave the masking on only where the hide glue will be. My present Gibson does not have the same kind of tone ring – it is set on top of the wood rim and not glued on, so I can’t copy from that. Hmm, sounds like a call to Eric Sullivan.
And I realize that after answering the tone ring question I am left primarily with the wood finishing tasks and the challenge of getting that mirror finish from the urethane on the neck and resonator. I have had some prior experience doing this with my Mom’s Hope Chest and a dresser top. I am anticipating needing to build a small paint spray booth. We will see.
March 7 – Picking a Color and Staining
So what’s next? I am waiting on my hide glue and my hide glue pot (more on this later on) so the next thing is to start some of the finishing. Staining is first. I am looking for a dark but natural finish to show off the curly maple in the neck and resonator. Also the resonator back is a bullseye with 3 rings. I decided to stain the rings in alternating and contrasting light and dark, with the edge of the resonator that is mostly what folks see as the 4th dark ring. So for the dark I decided on Minwax dark walnut and for the light a Vaspar honey maple, a bit of yellowish red. The neck will be the dark walnut.
The guts of a banjo are the wood rim and the flange, to which the neck, head and resonator all attach. The wood rim is topped with the brass tone ring, the part that makes the banjo so heavy but what gives it that sharp ringing sound. A 3/4″ edge of the wood rim shows to the outside like a highlight on the banjo body and I decided it would be the walnut color. The whole rim gets finished except for the top edge where the tone ring gets glued on with the hide glue.
So for the staining I had to mask off the fretboard bindings and the top edges of the wood rim. I put the stain on with a small horsehair brush carefully on the rim and neck. This of course after some final sanding with 220 grit paper and wiping with a tack rag. This was a pretty mundane task, and to my great delight any stain that wicked up onto the neck bindings came off easily with a little mineral spirits.
February 28 – On to the Fretboard
To fabricate a cradle to hold the neck when pressing in the fret wire (or frets) out comes the plunge router. I used my pin gauge to transfer the cross-sections of the neck at both ends to a length of 2×4 and then traced the outline of the neck onto the top of the board. I used a 1/2″ square channel bit to cut in the rough outline. Knowing that I would be lining the cavity with a couple thicknesses of leather padding I didn’t have to be too careful hitting the outline. After some trial and error I got a cavity with the neck resting against the bottom at both ends. Then an hour or so of rasping out the rounded contour of the neck ensued. Being the frugal sort (mostly) I had saved my old red suede guitar strap I made back in the 70’s. I glued this double thickness, conveniently sewn together, into the cradle after first fitting the neck to the cradle with the leather in place. You’ll see in the picture that the butt end of the neck hangs out of the cradle because it has a flat bottom. I added a 2×6 to the bottom of the cradle to extend it for this. I had to round down the cradle at both ends to accommodate the curve of the neck. So the picture shows the neck in its cradle ready to go.
You can just see the red suede sticking up along the edge of the neck.
Now to install the frets. First off you have noticed that the neck has its plastic binding installed along the edges of the fretboard. So the ends of each fret have to be notched so as to fit inside the bindings and not cut through. So the operation was cut the fret wire roughly to length, use a nipper to cut a notch in each end then hand file the notch flat with the underside of the wire so it would press in flat. Unfortunately for the 20th fret I got distracted and forgot to notch the ends, so the tee shows through the binding, but it is neat enough that it looks like it was planned that way. My existing Gibson banjo has all these tees showing because it has no edge bindings, so no worries.
a saw groove to hold the fret wire for filing
The mention of super glue begs the question “How do you clean-up the glue that squeezes out onto the fretboard?” Another Sullivan trick – coat the fretboard with Johnson’s paste wax. Worked like butter – it just flaked right off. So here is the fretted neck.
Now to dress the ends of the frets. I took some time to inspect the angle of the frets on my existing Gibson banjo and measured the angle at 45°, which made sense. Now another Eric Sullivan trick – make a filing block to hold the file at the proper angle and hold it against the side of the neck. Presto, all the fret ends get dressed exactly the same. I made two blocks from an old piece of bathroom vanity countertop backsplash (never throw anything away) – one 7″ long for the long runs and one 3″ long for the short part on the 5th string side of the neck. I also made the longer block to hold my thicker faster cutting diamond file on one side and my thinner finer file on the other – I got impatient using the latter on the really long ends sticking out and wanted to speed things up. I cut the file grooves on the table saw and cut the blocks to length on my miter box chop saw. Here are the blocks.
Here is the dressed neck. Had a bit of trouble nicking the edge bindings but sanded these out carefully.
February 22, 2017
The first thing I did was to ream out the tuner holes to the proper diameter for the tuners purchased in 2007. Eric Sullivan pointed this out to me. It was a simple fix – a strip of 80 grit sandpaper wrapped around an old Tinker Toy dowel. It took all of 15 minutes
The first major task will be making and installing the frets. The steps will be roughly:
- Cut to length
- notch the ends into a “T” shape
- clean out the excess binding glue from the fret grooves
- install the frets with an arbor press and superglue
- clean off excess glue
- dress the fret ends with a filing block
I will need to find an arbor press and make a filing jig.
I have been collecting the necessary equipment and getting ready to fabricate the cradle needed to install the frets into the neck. I bought a 1-ton arbor press at Harbor Freight last week. I found a YouTube video on installing guitar frets with the arbor press and saw that I would need to fabricate a flat end the width of the neck for the press. With that in mind I borrowed an electric hand grinder with cutoff blades from buddy Pete Shaw. I salvaged a piece of T-rail from the garage door opener I recently replaced. Here is a picture of the hand grinder clamped down to the table saw while cutting the slot in the arbor ram to accept the T-rail. The sparks were pretty. Note ear protection and safety glasses. The 1″ deep slot took about 90 minutes all told to cut including dressing it with a hand file, primarily because with the width of the cut off blade I had to make two passes. I centered it by flipping the ram over for the second pass, adjusting the height of the ram relative to the blade
to get the proper width. Then I drilled and tapped a 5/16″
bolt hole through the ram at the slot to fasten the T-rail piece. The finished product came out very good, although the T-rail is 1/16″ off center on the ram end-to-end. The arbor press before and after modification is shown in the pictures. The next step is to rout out a cradle for the neck to protect it during the fret pressing.
February 5, 2017
Here are all the parts ready to start. Now if I can just get’em together.
January 27, 2017
In the summer of 2007 I found First Quality Music, home of the Sullivan banjo, when looking for a new resonator for my existing Gibson banjo. I was referred to them by Gibson, who had their banjo factory in Louisville, which has since closed. The First Quality catalog had a complete line of banjo parts. I had cracked my existing resonator backing the car into it (while in its case) sometime in the late 1980’s – early 90’s. Eric Sullivan made me a new one, and it was so inexpensive I started looking at additional options. I noticed that they made custom banjo necks. The prices were so reasonable I hatched the idea of using the pot assembly from my existing Gibson and adding a custom Sullivan neck and resonator. I ordered a neck with an inlaid fingerboard and “Grauvogel” inlaid in the headstock along with a “bullseye” resonator. I had the neck and resonator for several months before I started working on them, the detail of the finishing being rather intimidating. I got the neck sanded into shape and its edge bindings attached and sanded. I got the edge bindings and bullseye purfling installed on the resonator and sanded out. Then from the winter of ’07 until the winter of ’17 the neck and resonator sat in their boxes in the basement.
With our annual anniversary trip coming up I made contact with Eric Sullivan and explained my situation and my planned project. He invited me to stop in on our way to Gatlinburg and he would help me get all the remaining pieces together. My visit with him turned out to be much more detailed as he shared many tips on how to put things together – how to cut the fret wire, install the fret wire, dress the ends of the frets, sand and stain the wood, clean the stain from the bindings and assemble the pot. He took my order for the wood rim and machined it to fit the resonator I had and the rim I was buying. He also drilled and installed the lag bolts into the neck for attaching it to the wood rim. We picked everything up on our return on February 4.
For my birthday this year I arranged to buy all the remaining parts for my new banjo from Sullivan Banjo in Louisville. This project has been a long time coming but the time is now, with my retirement pretty much in full swing . The main spark that rekindled the fire to do this project was listening to old banjo tracks I recorded with the People of Praise Music Ministry between 1981-1986. These recently became available digitally on CD, together with all Mary Ann’s and my songs from that era, through Dave Szumski, our drummer, who got them transferred from the original cassettes. In the process of compiling these songs I found out that going from a boom box cassette player directly into the computer using my USB-to-phono direct recording cable gave just as good a quality conversion as what Dave had given me. So I remastered all of our People of Praise music, transferred my other songs from cassettes and added my new songs to compile a 2-CD collection for the family, “Songs from the Heart”.