Harmony H1457 archtop guitar repair
- Top triage
- Crack repairs
- My back is killing me
- Stripping the top
- Putty problems
- Putty solutions
- Final finish prep
- Finish application
Gluing pieces of wood back together is one thing... stripping off a 50 year old finish and redoing it with a spray can of lacquer is another. I'm not so sure this is a good idea. But the wife says it's ugly.
All taped up and ready to be destroyed.
There it is after a couple hours with 60 grit sandpaper. Most of the stains in the treble have been sanded out and the only thing that really stands out is the long cracks I superglued in the middle. The lumpiness in the center prevents those cracks from getting sanded flat so the glue shows a bit. There's still a few darker patches here and there where the old finish isn't quite gone - again, due to the lumpiness. Another couple hours of grinding on it should smooth it out. Good thing spruce is a soft wood.
Once I got it sanded down to 220 grit it was still a little rough. So I wetted the wood to raise the grain, then made another pass at 220 grit. When I did this a bunch of little pieces of the grain ripped up. Here's an example.
Spruce is really weak and wet, sticky sandpaper just destroys it.
There's a lot of small grooves (see above) and dents in the top and that one big crack. I got some "natural color" wood putty from Stew-Mac. It's great stuff and really easy to work with. There's just one problem:
It's not natural color at all. It's just white. This didn't really occur to me while I was applying it. When the wood is wetted down (to emulate the final lacquered appearance) it's really obvious. This putty thing was a mistake.
Death to the old putty, long live the new putty. This stuff is an oil-based putty that comes in a bunch of wood colors. You can mix the colors together like pain to get the right color. It dries, but not really very hard.
I mixed these three colors together, dug out the top of the white putty, and filled in with the mixture. Not bad:
The big crack is still noticeable but the rest of the top looks great. Even wetted down the putty isn't noticeable unless you're looking very closely. I can't say how it will look with lacquer but it could be worse.
Cracks are filled and everything is sanded down with 220 grit. I put a screw into the neck block so that I can hang it in my high-tech finishing chamber.
I'll have to put some newspaper down before I start spraying.
Here's my finishing plans, essentially taken from Stew-Mac's instructions:
- Sanded to 220 grit.
- No grain filler since spruce is a tight-grained wood.
- 4 coats of sealer (ColorTone Aerosol). 45 minutes between 1st and 2nd coat, 2 hours between subsequent coats.
- 8 coats of lacquer (ColorTone Aerosol). Again, 2 hours between subsequent coats.
- Sand (800 grit, wet sanding) and buff final finish.
Here it is after 4 coats of sealer and 5 coats of clear coat. I've been leaving 4 hours or so between coats since that is recommended on the can.