Acoustic Guitar Construction

I understand that now, at the Martin Factory and those plants with CNC equipment, the finish is removed from the bridge area with a machining operation.

Years ago I saw that Martin used a mask and that is the way I do it today. the mask is made a few.000" small all around the profile, after removal I knock the tiny ridge down with a single edge razor blade (I think I saw that at the Martin factory as well) lastly, I sand a infinitesimal bevel on the bridge glue surface perimeter to assure complete contact with the bare surfaces on the sound-board and bridge.

Marc Dutko wrote:John do you do the same in the fingerboard area? Or just mask that off?

I continued to try and use the mask on the fingerboard extension. On my last I knocked off the finish build up, but thought I could get away with leaving finish on the edge as I really only tack the fret board down with a bit of glue more to the center of the fret board. But while leveling the frets the extension popped up on me. So I cleared the finish as I described above. and re-glued the fret board extension.

I have tried the mask just a bit small, but always seemed to stretch it or cut it too small or some other issues. I am better with wood and chisels than I am with tape. But I know a lot of builder have great success doing it as Ken describes.

GRR, more bad words. Did a big drip on the lower bout and didnt notice until it was half dry, scraped with a razor blade and sanded a little, should i put a coat or two on the area or wait a couple of weeks and sand the area properly and then reapply?

thanks all,
Mike

Many times, I have used a paper towel with some mineral spirits to even out an area - it helps to 'melt' the TO a bit and makes blending easier.

I have a different t/0 finish problem. My last coat went on a few days ago. While preparing the nut I followed a video tip and ground a pencil in half on the disc sander to mark the fret height. The result was some graphite dust landed on the spruce top. I tried gently brushing it off with a soft brush, but it still left several black blotches in the finish. Any suggestions how to proceed?

Hopefully others will chime in, I don't use TO -- but seems that scraping with a single edge razor blade would be effective. Sanding will tend to "smear in" the stains.

I came up with an unorthodox fix to my graphite dust problem. I had my wife pick up a lint roller.
The tape is moderately tacky and paper backed, about 4" wide. I warmed up the soundboard with a hair dryer and applied the tape covering everything. I then warned the tape and rubbed it in with a plastic backed paint pad, going with the grain. I pealed it off carefully and 95% of the black came off with it. Absolutely no damage to the to oil finish. I then wiped it down wit lighter fluid (Ca. resident, no " naphtha" available) an it cleaned up nicely. I'm so happy I didn't ruin it with my carelessness. Go it strung up and set up today. It sounds wonderful! Finished pics next week.