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I'm about to start french polishing my first guitar - flamenco; spruce top, cypress b/s, ebony fretboard, cedar neck, brw binding and headplate.
When pore filling with pumice, I suppose I only need to pore fill the neck, as spruce and cypress are not open pore woods and my brw has only a very, very small pores (much smaller than cedar).
The question is: when pore filling neck, how to avoid bringing light cedar dust into ebony and dark ebony dust into cedar? Or would it not be visible if I just circled with the muneca from one wood to the other?
I have Ron Fernandez video and Milburn tutorial but they don't mention this particular thing.
Thanks a lot!

To avoid contamination of my maple purflings and mahogany bindings with East Indian rosewood I chose to do an epoxy pore fill under my french polish. Used system 3 epoxy with silica filler for my pore fill and mixed my own shellac from buttons, turned out beautiful and my maple purflings are still nice and bright. You may be surprised how those tiny pores in the rosewood stand out after finishing if they are not filled.

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Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/

Thanks Brian,
you convinced me to pore fill the rosewood too
I'd rather master the pumice pore filling and avoid the epoxy - I mean, people have been pore filling flamenco/classical guitars this way for decades, there has to be a way to do it right and avoid wood dust contamination...

A couple good spit coats then go at it with the pumice should do it.

Thanks Mark, I'll give it a try.

I had read somewhere that some of the old timers pore filled with egg whites back in the 1800's. I'm guessing this was to avoid the darker wood contaminating the delicate purfs.

I did find this tutorial, looks like they address the issue and do a pumice fill.
http://www.luthiersupply.com/howto_page.html

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Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/

Egg white is an acceptable way to pore fill. The method is to use egg white and sand a slurry with something like 220 - 240 wet/dry paper, then work into the pores - let dry - sand back - repeat. Probably takes about 3 passes on EIR. Egg white dries in about 3 - 4 hours. Seems dry before that, but I'd wait till it's really dry. It is also a good sizing agent for the top of the guitar. Raises the grain a bit, so sand that back lightly after sizing.

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Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

I always thought that pumice grain filling involved fine wood fibers filling the pores anyway--the pumice grinds down surrounding wood very finely and it fills the pores in a sort of slurry that mixes with spit coats of shellac. Similar to very fine sawdust. Doesn't seem like much of a problem having those pores fill with a wood, shellac and pumice, even if the wood wasn't completely from one type. The clarity wouldn't be much effected if at all.

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"Preoccupation with an effect gives it power and enhances the error"
from "Your Owner's Manual" by Burt Hotchkiss.

+1 on egg whites.

I tried the pumice thing a couple times. Just made a huge mess of the shellac.
Used less shellac, didn't fill pores.

Tried egg whites. Found it to be idiot proof. Couple passes do need to be done but is VERY quick and can be finished almost immediately after it is dry (listen to Waddy on dry time)
If you try it, mentally divide your back up into five or six areas and do one area at a time. The back is too big to do all at once. Concentrate on getting the pores filled in smaller sections before moving on to the next.

Good luck,


Dave

Thanks for the replies, guys.
In case the pumice thing won't work out I'll try the egg white.

Waddy,

What do you mean by a "sizing agent" ??

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It's this new idea from recent decades that everyone gets a participation award. - MUX

Some folks think it adds a bit of stiffness to the top, sort of like starching a shirt. Mostly, I think it seals the top a bit, and makes the French polishing of the top go a little more smoothly. As I said, it does raise the grain a bit, so you have to sand it back a bit with something like 220 grit or higher. Some careful cross grain sanding brings out the silk in a top too, also at 220 or higher grit.

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Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

I talk in depth about pore filling in my French polish DVD. I also show how to size the wood using egg whites.

Robbie, that's not super helpful in an online open forum!

I have pore filled using egg white for some years now, I've tried all of the others and I'm not sure why anyone uses a different method. There is a picture guide to the way I do this on another forum, in one of my build threads, but basically it is just as Waddy describes, use the egg white straight from the shell, use 240 grit sandpaper wet with the egg white and sand the wood squeegeeing the egg white/wood dust slurry into the pores, leave the egg white to dry, sand back and repeat as neccessary. You really need to do this on bare wood.

As far as sizing the top with egg white prior to finishing, it seals the top and prevents too much filler penetration, as well as stiffening the top. I have restored several antique German and other Northern European lutes and early guitars that had soundboards finished solely with the application of several coats of egg white, If I have to clean the surface then I just renew the egg white finish.

Colin

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I don't believe in anything, I simply make use of a set of reasonable working hypotheses.

I have spoken ad nauseum on this and other forums many times in the past about pore filling and French polish as well as many other topics. The information is there.

it sounds interesting the egg white method. think im gonna try it on my next build.
does it work also if you are to spray with nitro or poly on it? or it just works as a shellac pore filler?

It works fine with nitro but I put a sealer down afetr the egg white, either a vinyl sealer or shellac.

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Jim Watts
http://jameswattsguitars.com