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Hi everyone!

I relatively new to finish, and I'm on my first attempt on french polishing an instrument (Uke). I've done some tests on scrap, and I don't seem to have problem with my french polishing, but I do with the porefill. After a washcoat of shellac, I began to porefill with pumice, alcool and a bit of shellac some times, but the porefill never took the wood's dust and stayed white. (I was on mahog) I then switched to rotten stone. Same thing, but gray-black. Moreover, I had some section of the porefill that get out when I began to rub my shellac.

What do you guys think I'm doing wrong here?
Why are you proceeding?

Thanks!
Francis

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Francis Richer, Montréal
Les Guitares F&M Guitars

As you can also read in the other current topic on pore filling with pumice, I'm no expert on french polishing, but I'll give it a shot.
My guess would be that during the filling process, your movements might be too quick, and/or you are not using enough alcohol. The pore filling is a relatively wet process. The alcohol will extract colour from the wood, which will then colour the pumice. You need to give the pumice the time to pick up the colour. So slow circular motions and enough alcohol should do the trick, I guess.
It might be that as the alcohol evaporates, the pumice will still be a bit lighter in colour, but this shouldn't always be a problem, since it will darken again when you apply shellac (or just ethanol, if you want to have a quick look).
I don't use a wash coat for pore filling any more by the way (see other topic).

Just my 2 cents.
good luck.

You have to make sure you've "cleared" the pumice, otherwise it will show up white in the pores. Clearing means that once you've charged your pad with pumice, you need to add alcohol so there is no dry pumice on the pad. Add alcohol, smooth it around a bit, and you should be good to go.

Steve

Three 0 and four 0 pumice will clear and not show. Rotten stone stays gray. Save it for polishing. I do a couple of spit coats (1lb shellac) then use only alcohol while pore filling. If I am filling something with large pores I will use epoxy or LMI acrylic filler rather that the three to four pumice filling sessions.

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GEO
perpetual beginner

Thanks guys! These are good hints!

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Francis Richer, Montréal
Les Guitares F&M Guitars