Well. Its been a bit since I posted, but I have been working on Yoda. I have it assembled except for the fretboard. I have it stained and its a good match. I had installed several frets, but have removed them and am starting over. This time, I will install the fretboard and its binding, then install the frets so that the fret board is totally flat to the neck and the frets can overhang the binding properly. I have learned that I need to pre-bend the frets and notch them around the binding, so the ones I installed are too short. I ordered more fret wire and it came within a day--Stew-Mac is very good in this regard.
I removed the frets and sanded the fretboard smooth (again). I filled some of the divots from the fret removal (again) with a different filler--no better than the first. I stained it all ebony (again). The stain did not soak into the filler (again). I am dis-satisfied (again).
So I switched to sealing the guitar, since this has to be done before I mount the fretboard (the fretboard will have no sealer on it). Although I think catalyzed lacquer is the right product to use, the elf at the PRO Sherwin Williams store told me that the existing finish looked like polyurethane and convinced me that water based poly will be just as good if not better than lacquer, and I wont have to worry about compatibility.
So I bought the product he recommended. I got a new gravity feed spray gun from the China Depot and set about the process. I was very careful to read everything I could about the product. I found nothing specific about its spray-ability, but the SW elf assured me it is spray-able. I set up a test board and spent a considerable amount of time adjusting to get what I imagined was the best spray pattern. I had read several articles about spraying, but never actually did it, so I wasn't sure what I was looking for. I talked to some people who had what they considered to be great success with far less fussiness than I was investing, so I expected stellar results. Finally, though with some trepidation, I hung the guitar from my garage door track with a piece of ought copper ground wire through one of the tuner peg holes. And I sprayed.
It did not go well. There was a lot of orange peel. A lot. I hoped it would flow out, but it wasn't flowing. I didn't know what to do. Using gambler's logic, I sprayed more, hoping that more material would increase the flow. It did. I now had very substantial runs. And orange peel. I stopped and waited about 2 hours for it to dry. While I was waiting, I went to Lowes and bought some 220 and 400 grit sandpaper. And I then sanded the entire thing by hand. This removed a lot of the urethane, and some stain. It was getting ugly.
Note: I, like many others, have always assumed that sandpaper, like metal files, lasted far longer than it actually does. The 3M sandpaper I bought surprised the Hell out of me. Even at 220 grit, I found it too aggressive for this stage. My experience with sandpaper in the past has not yielded this type of cutting power. I don't know if its the 3M brand or what, but it is impressive.
I re-stained the bare spots and got what I thought was a decent blend, but not as good as the original job. After waiting for it to dry (it was about 88 degrees in the shop, but the humidity was only about 55%) and reading some more, I set up to spray the urethane again. Based on an article in Fine Woodworking, I cut the urethane first 10%, then 20% to get it to thin so it would atomize better. I had already tried upping the pressure to nearly 50PSI to get atomization, which by all accounts is the outer limits for a gravity feed gun. I fussed with everything I could think of for about a half hour, then decided to spray it laying down this time (the guitar, not me). It was horrible. With more faulty logic, I decided to try to "save" it by brushing out the orange peel and adding urethane by hand. I now had brush strokes you could loose a jeep in. The stuff would not flow.
At this point, I don't know what the problem is. It could be the cheap spray gun, though I doubt it--there is not a lot that could malfunction and it does actually spray. It could be the product just being inappropriate for this application--I was not enthusiastic about it in the first place. It could be my inexperience with the application and the product, though all indications are that inexperience leads to extra work, not total failure. I'm not yet sure what I'm going to do, but one thing is clear--I will have to sand the entire thing down to bare wood and start over again at this point. Dammit.
