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Everybody,
I'm very close to finishing my first guitar. Pictures will be posted once I'm done. I chose a French polish finish. Last night I applied McGuires #7 glazing to the back and was rewarded by a nice shiney surface but it also revealed a couple spots on the perimeter which seem a little thin. Can I apply FP right over the #7 or do I need to lightly sand the back? The #7 also brought out a few swirls from the FP. I saw somewhere on this forum a discussion about using McGuires swirl remover. So now the question is how long after touching up the thin areas should I wait to use the swirl remover and re-glaze with #7?

One of the things I learned from all this is I didn't have bright enough lighting while working on the finish. And pay attention to the edges when French polishing. BTW this is a great place to hang out.

Ric, The nice thing about shellac is that it will stick to almost anything... but the polish you used most likely left a residue and it would be nice to just do a wipe-down with some mineral spirits to remove any oils or wax left behind. After that there should be no problem with continuing to apply your FP and get the build-up in those thin areas.

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Peter

If you are doing "spiriting off/stiffing off" after each body session, as recommended, you shouldn't be having much in the way of swirls and scratches in the finish. The glazing sessions should cover all scratches after a thorough "stiffing off" session. The gloss should be relatively high without the use of any abrasives like Swirl Remover. Not saying it won't make it glossier, but it is not needed for a pretty nice shine!

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Waddy

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Sound Clips of most of my guitars

All I can say is my right arm is much more developed than my left after French polish work But I suspected my fp technique is flawed. This is the first time I've tried French polish on anything I've built. I do have a nice sheen but a couple small areas of the perimeter of the back looks like it could use some more pore filling. Once the Meguires was applied it showed the flaws. My plan is to pore fill the problem areas then do a few more sessions.

Guess I go back to my original question. How should I prepare the back of my guitar where I used the Meguires #7 before proceeding with more fp sessions?

Dang! I should have read your remarks more carefully Peter. Thanks for the help.

Additional pore filling at this point isn't going to be much help, fill any grains with shellac by wiping across, not along the grain.

It's pretty common to use #7 even if your FP technique is good.
It is very satisfying to rub and buff it to a mirror, but wait a while for the shellac to harden some, at least a week or more, or you'll be removing too much of your hard-won polish.

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It is never too late to pore fill! I have filled so many pores after working up a polish you wouldn't believe. A touch(drop or two) of shellac, a dusting of pumice on the muneca, and about 3 - 4 drops of alcohol, a drop of oil spread out on the muneca and you are in business. Don't try to work too big an area, but pores will fill just fine. Takes some passes. Work an area, move to another. Keep moving around. Repeat.

Before starting back up, I'd spirit off the surface well, though #7 is not supposed to leave any residue. Not sure I believe it.

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Waddy

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Sound Clips of most of my guitars

Ric, I was hoping someone would give an answer myself. After you put on a wax coat on, and your not happy with it, how to you remove it, so you can add more finish or porefill? Sand, scrape, or chemical removal?

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Jason Moe
LaCrosse WI 54601

If you put wax on the guitar, mineral spirits or Naphtha will remove it without damage to the finish. I would then spirit off before continuing the polishing process, to make sure all residue is removed. I would never recommend waxing a FP finish until you are absolutely sure it's finished. To know, you need to wait several weeks to make sure the pores do not sink back. However, Meguire's finishing products (Swirl Remover and Show Car Glaze) don't contain any wax.

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Waddy

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Sound Clips of most of my guitars

Waddy, do you apply anything as a "top coat", like a wax or McGuires when you're satisfied your done FPing? If so, what do you use? Beth

Waddy,
Thanks for the helpful info. I waited about a month after I thought I was finished with the fp before applying Meguires. My thought was to let the shellac harden. I didn't realize the finish could "sink" and reveal some pores. I just applied the Meguires without close examination of the surface. Gonna hit the pumice and shellac after wiping down with naptha and hopefully correct the situation. In my original post I said things looked thin but now I believe what I saw was really the pore problem, I hope.

How long after filling and correcting the finish should I wait to apply Meguires?

Beth, sometimes I use Swirl Remover and Show Car Glaze, both of which are polishes, not waxes. They do bring the gloss up on the finish. I have never used any waxes, though maybe I should. I don't know.

Ric, I think that's exactly what happened. There's no need to wait a month, but a couple of weeks is good. When using pumice to fill on a nearly finished guitar, go easy. It does not require a lot of very hard pressure. If you do use too much pressure, the muneca will try to grab a bit more. Don't be afraid to use oil, but spirit off after every couple of sessions. I have noticed that when I do that, it takes off some of that finish that builds around the pores. You can do a session or two, and it looks like you aren't making any progress, then you spirit off, and you realize you are. At least that's my experience. YMMV!

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Waddy

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Sound Clips of most of my guitars

Thanks, Waddy. A followup then is: do those polishes just add to the gloss, or do they also provide some additional protection, given that FP is not very protective?
Also, just a quick shout out to you, Waddy....just finished watching Robbie's "Rosette making" video, and I recognized a few of your rosettes...they are so beautiful and well executed! Beth

I've had no problem FP over areas that I've rubbed out before (H4,H2,H7) with the Meguires. It says that it is "paintable" right on the container
and I've always taken that to mean it's compatible with additional applications of whatever.
Recently I'm re-working the finish on a guitar which I built in 1989. This is way back when I used pumice for fill (not very effectively in my case) as well as oil in my FP process. Around the pores in a few areas I can see where the polish shrunk and checked ever-so-slightly. I'm wondering if the oil trapped in the finish slowly dried out over the twenty or so years or what. The finish (aside from a bit of crackling over the marquetrys) was still in quite good shape.

David,
You don't use oil when you FP anymore? I have not heard of a method (in my VAST experience ) that doesn't use some oil.
I would be interested in a quick outline of your technique, though I don't want to hijack the topic...feel free to PM me if you respond. Thanks, Beth

Lately I've cut back quite a lot on the oil. I now use just one drop per session for the entire guitar. Before I used to put a drop every 3-4 pad fills, but I was also using straight 2 pound cut which can get sticky very fast. I now use something between 1 and 1.5 cut (can't tell exactly considering the lost wax and alcohol during filtering)
The trick is to make sure you are not lingering much in one spot. With oil you can do that more, not without.

As for rubbing, I only used rottenstone with oil, and it seems to work fine just a couple days after the last session.

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Build log

It just makes an icky, black, mushy mess! If I recall, Colin uses Rottenstone too, but uses it dry with a felt block for rubbing out.

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Waddy

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Sound Clips of most of my guitars

I've used rottenstone for years with just an old t-shirt and spit. I know, not real high-tech but it works just fine. A felt block would be better and I think I would prefer using water or mineral spirits instead of oil. I have not used rottenstone on FP so can't speak to that.

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Steve Smith
"Music is what feelings sound like"

Yap that's it, that black muck. It works but you need to rub to your wits end. I use some felt from an old hat. It doesn't seem to work well on sanded FP. Works much better over a glazed/spirited surface I think. I can see the reflections moving from mushy clear to decently clear, clear enough for a classical. Most CG users don't expect the buffed mirror thing.

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Build log