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I started French polishing today. There were several reasons I decided to go this with this method:
1. Kathy Matushita's Zebrawood OM looks fantastic with that finish
2. She made the process look simple and peaceful
3. She said it would sound better
4. I didn't want the build to end so soon. I'm only building my first guitar once. I was willing to find a reason to stretch out the process

I completed two sessions tonight. Kathy showed me some of Tom Bill's videos from The Art of French Polishing while I worked.

Be sure you allow adequate drying time between coats. I was impatient and had some problems. "Dry to the touch" is not sufficiently dry.

allow adequate drying time between coats

Do you recommend an hour, or a day, or....?

I complete FP in about a weekend. There are times when the finish is hard to work with. At that time stop and let it rest. For me, that normally will be around an hour or two. French polish means a lot of different things to different people. Any answer you get will be dependent on the process being used. My process on a guitar using oil as a lubricant basically allows me to go as long as I want to. I do rest a surface between sessions as long as it takes me to do a session on the other surfaces of the guitar. If I finish a guitar without oil I find I do need to let the finish rest at times as it is hard to work with a soft finish without a lubricant.

I didn't use oil very much. I think if I could muster enough self-control, I'd wait at least 3-4 hours between coats and then after a couple of coats wait overnight before resuming.

Realize that I didn't have much of an idea of what I was doing, which I'm sure made the whole process more difficult than it needed to be. Even so, it was pretty clear that waiting longer between coats was A Good Thing To Do.

Another consideration in using shellac is that the older the solution gets, the slower the drying. Old shellac will be soft, slow to dry and 'sticky'. Fresh shellac will dry very fast and can be worked in short time. A good test is to place a drop on glass and test its dryness/hardness. Good stuff will be ready in minutes. An uncontrollable factor is that shellac is a complicated polyester resin whose composition will vary and that affects hardness, drying time, etc. First thing I do when I run into cranky FP is suspect the freshness of the shellac and mix up a new batch or get new flakes and do the same.

Mine was freshly mixed -- within a couple of weeks. It should have been good.

MaineGeezer wrote:Mine was freshly mixed -- within a couple of weeks. It should have been good.

Hard to say what the cause was. I have some old super blonde flakes from 1990 and mixed a jar 2# cut in January figuring it probably wouldn't be good. I couldn't get it to go into solution and put it away until I saw your last post. It finally did go into solution and I tried it a few minutes ago. This shellac dried in a couple of minutes, something I find quite unexpected. The stuff I bought at the hardware store this year is just barely adequate. The manufacturers used to date stamp and don't anymore.

After 6 rounds I noticed a spot on the neck by where the low E tuner would go. It appeared there may be a bit of oil in the wood, and the surrounding area wasn't picking up the shine like the rest of the neck.

Here's what I think may have happened: I wet down the linen with alcohol to soften it. I think this spot on the neck may have been wiped down with pure alcohol which stripped away the finish. Then when I was using the Olive Oil/Shellac/Walnut Oil/Alcohol rub the oil got into the wood.

I took it to Kathy and she applied two coats of shellac without walnut oil. That seems to have take care of the issue.

Overall I'm very pleased with French polishing. It is a peaceful process and I feel like I have a better chance of fixing finish anomalies vs using sprayed lacquer.

Stearates, which are a component in some non-loading sandpapers, can cause fisheye. Check your sandpaper. 3M's 7x sandpaper is formulated with stearates (yellow sandpaper). I'm not sure about their 10x, (red) paper.