Official Luthiers Forum!

I plan to French Polish my guitar. What's the best method/product to
fill the pores in Indian rosewood, in mahogany?

What are the best colorants?

Is epoxy filling absolutely neccessary ?

Thanks,

-jj

Jim, I've tried all kinds of pore filler for rosewood. Epoxy was good, but in my experience, it was abit time consuming. Apply epoxy, sand down (either to wood or to an even coat of epoxy - you'll have two polarized camps debating on that one). I decided to sand back to wood with System III. When the light catches the guitar at certain angles, the pores shine like they're full of glass.

I tried a paste type filler, and depite the ease of use, the guy in the store told me it would dry 'clear' but it was far from it. The pores wound up being way lighter in color. Now there's a lesson there about testing on scrap first when using a new product. Although I'll admit that if the color would have been perfect, it was pretty easy and did it's job well.

My favorite fill, and I've used it on Wenge, which basically has craters instead of pores, (seriously, it makes oak look like maple) is old school pumice and shellac. It looks amazing, it's quick and painless. The color match is unbeatable.

I'll lay down 2-3 base coats of shellac with a pad/muneca. Just straight passes, no need to get all fancy, but you can certainly try laying it down with rotating spit-shine like motions if that suits your fancy. Once it's dry, which is a matter of minutes, you're good to go.

What I like most about this is that a screw up takes minutes to fix. Too much pumice, no problem. Sand back to wood, add shellac, repeat.

I take a white piece of paper, sprinkle the pumice on it, shake the piece around so that the pumice is distributed over a large area. With your dedicated pad, bite off just a little bit of the pumice, give the pad a few drops of methyl hydrate (if that's the solvent you're using) and then slowly start working the pad in small circular motions, adding a bit of pressure, but not too much. The mix of shellac, pumice and methyl hydrate (Denatured alcohol) will create a little slurry that fills the pores just beautifully.

If you wind up with too much slurry and it seems to dry on the guitar, just add a few drops of the DA and you're good to go. You'll soon get the feel for the proper pumice/DA mix and how much mileage you get out of each application.

It dries super quickly too. And from what I've seen, doesn't shrink back at all.

I've used it under Nitro and French polish with good results.

I do believe it's Howard Klepper's pore fill of choice as well.

If you want to go real old school, there is also an egg white slurry that's been talked about on this forum. I've always wanted to try it, but never really got around to trying it. But I will some day!

I hope this helps, and good luck!

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I'd like to be able to prove, just for once, that money wouldn't make me happy...

I use the Pumice method on EI Rosewood. For some odd reason I just can't get a good colour match on Walnut. I've tried 'clearing' the pumice with copious amounts of alcohol and I still get the odd pores that show a lighter colour.
Pore fillers work better when the filler is clear or darker than the surrounding wood. If the filler dries to a lighter colour than the surrounding wood they leap out at the viewer.
I think the Pumice method works well on Rosewoods because of the amount of Oils and natural dyes that the wood contains.
I've had problems with Walnut but Mahogany seems OK. . . it's odd but that's my experience. Others may have better luck with Walnut but I've given up.
I never liked the Oil paste fillers. Water based types are easier to deal with. Egg White sand fill is OK but not my favourite. Oil sand fill can be very good (colour wise) but you have to be careful and it takes time to dry/harden.
I haven't tried Epoxy/CA.

I don't know if it is still his preference, but Richard Brune wrote an article where he used some kind of paste filler. He used black on the rosewood body and red on the mahogany neck. I saw some guitars in his shop in progress with a rather thick layer of this filler awaiting drying. Of course, the surplus is sanded off.

Many years ago, Brune mentioned to me that filing with egg white and pumice is good and an old standard. The application method is the same as described in the post above for shellac and pumice, but the egg white takes a longer time to dry.

I am too allergic to epoxy to attempt using it.

I have no personal opinion on these, as I have tried none of them.

All the commercial pore fillers will work great if the directions are followed carefully. I believe the single most important thing with any finishing system is to make sure all the coatings are compatible -- the only way to do that and not have doubts is to contact the manufactures and tell them your plans. I have communicated with all the major coating makers and all the tech supports are ready and willing to share information.

Seeing I did respond to this post, I'd like to mention that with few exceptions there is no "best" anything when it comes to the guitar making craft -- favorite, preferred, opinion, view etc. is what it seems you are seeking.

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Ken Cierp

http://www.kennethmichaelguitars.com/

You sure? Egg White is essentially water based and dries very fast. Shellac dries fast too but takes longer to become hard.
Anyway, thanks for the Pumice/Egg White information. I've used both separately but never thought of combining the two.
I'm off to give it a trial. . . . on Walnut!

Maybe he does finishing in the winter, and it's too cold to evaporate water quickly?

Let us know how the walnut test goes! I've gotten patches of light pores with pumice on it as well, and thought it was just me getting impatient and putting too much pumice on the pad.


I can't believe you managed to fill wenge with pumice... and to call it easy? That would take me literally days of work, with the fine pumice LMI sells. Not to mention probably 10-20 muneca covers. Are you using coarse stuff?

I have been getting better at pumice filling lately, but it's still nowhere near quick or painless. But I do love the perfect color match and self-leveling aspects of it. No need to sand it, which with most fillers will fluff various kinds of nasty dust into the air... including pumice, which is tiny particles of jagged rock.

One thing I've been meaning to do a scrap test with is a wash coat of shellac, followed by sanding with 220 grit wet/dry paper and alcohol, to hopefully fill the pores more quickly than fine pumice, and without the risk of light colored pores. Then after it dries fully, do a round of pumice filling with the fine stuff, to simultaneously top off the pores and remove the 220 grit scratches. Hopefully the wet/dry paper will hold onto all of its grit. A few blue grits in the pores of a dark wood would probably be fine, but in light colored woods they'd stick out like a sore thumb.

I sure would like to find a good colorant for epoxy. It just never seems to get dark enough using a slurry mixed with dust.

As I said, I have never used any of these. I just assumed that egg white would dry slower than alcohol.

Yeah, there is no best, only personal favorites. Here's mine:

For speed and ease of use - traditional oil based paste filler. It was just about the only filler used until the mid 90's. It's fast and it works. Color with UTC or oil stain or oil paint.

LMI microbead acrylic filler - works well if diluted to thick cream consistency, pretty much same technique as the oil stuff. Takes two coats. Very fast. Usually requires a bit of light sanding compared to oil paste, but clean up is easier.

Epoxy - I usually use this (z-poxy) these days cuz it's pretty, it's clear, and it pops the grain. However, it is way more work than paste filler, and it's messy. No, you don't have to use it if you don't want to.

Traditional pumice/shellac - even more tedious, but it does look great, especially under an FP finish. BTW, the usual luthier technique is a variation of the traditional FP method of using oil and pumice. Oil/pumice is much faster and easier, and it pops the grain, but obviously most luthiers don't want oil in their wood. Good for headstocks though.

Egg white - yeah it works if you like the look. It's not for me. The sheen/chatoyance is kind of odd, but it might be nice for lutes, etc.

Various water based fillers, usually PVA based - I've tried a couple and they were terrible, to the point where I sanded off the wood and tossed the can. If I feel especially adventurous, I may try timbermate some time, but I am skeptical.




LOL. That's what I thought too. I guess easy is relative. BTW I find FFF pumice about the perfect grade for pore filling, if you're enough of a masochist to do it.

Well I've done a quick trial of the Egg White/Pumice method. I really tried to grind the pumice into the wood so that it would pick up as much as the Walnut dust/dye as possible. The Egg White is very forgiving, much more so than Shellac/Pumice. I let it dry and did a quick French polish. In raking light and using magnification there were no missed Pores. I estimate they were 80% full. Another application may have improved that. I'm not entirely convinced of the colour on Walnut though. It isn't bad but neither is it as convincing as something like a paste filler or the Oil sand. Oil sand is the best I've used on Walnut. Pity it takes so long to dry and harden, it pops the grain and gives Walnut a real rich appearance that Shellac doesn't quite match.
The Egg White/Pumice might be very useful on Rosewood though. I strongly suspect that the colour won't be a problem, although these things should be tested. Last thing anyone wants is the White pores to start appearing.

I sure would like to find a good colorant for epoxy. It just never seems to get dark enough using a slurry mixed with dust.





http://www.stewmac.com/Materials_and_Su ... olors.html

I just used a thick slurry of 2# cut shellac with the pumice mixed in, and I couldn't have been more pleased with the result. It worked great for mahogany - 2 coats on a back and it was filled. I had never tried shellac/pumice pore filing before, but that part was very easy and required minimal sanding.

Glenn

These days I am using a sprayed polyester for pore fill under all my finishes. Back when I was doing more FP than spray finishes I used epoxy. I preferred the System 3 SB112 for it's clarity as opposed to z-poxy and others which have a serious yellow cast to them. I used the fumed silica as an expander so fewer coats of epoxy were necessary. Using an epoxy under a FP saves a lot of time and labor on the actual application of the shellac, about 50% in my experience. Yes the epoxy is a pain to deal with, one of the reasons I eventually went with a sprayed polyester basecoat.

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Brian

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

https://www.howardguitarsdelaware.com/

I like to pore fill with medium viscosity CA glue, and sand back to bare wood before finishing with nitro. It is clear, hard (does not shrink), fills and sands beautifully, quick and easy to do, and looks fine IMO. I have tried various epoxies as well as a few of the more traditional methods, but so far this seems to work best for my situation. The biggest drawback is probably the nasty fumes and the odor, but some brands offer less smelly varieties if that is a real problem.

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Rian Gitar og Mandolin

If using Pumice beware there are about 4 or 5 different grades of
it.

I also prefer CA, but I use the thin viscosity. It works really nicely for pore filling after it's gotten a bit old and doesn't dry too quickly.

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A man hears what he wants to hear, and disreguards the rest. Paul Simon

Have you ever tried powdered Lamp Black. You can get it at artist's supply stores. It will make the epoxy jet black.

Isn't there a black epoxy sold by StewMac or one of those suppliers?

I've tried them all and have settled on System 3 SB112 as Brian mentioned. Hard to mess it up.

BTW, I've never had any provide a sure-fire "no shrink-back" every time. Most times, but not all.

Michael, may I ask you what you don't like about egg white pore fill?

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member of the guild of professional dilettantes

It's just the colour. Not so much on Rosewood but with Walnut. All of these pore filling methods work, it's just a matter of whether it is fast enough and/or gives a very natural look to the wood. In terms of colour the best that I've found is clear shellac. It's slow to fill though.
I've done a couple of trials of an old furniture technique of filling pores. Pumice is sprinkled directly on to the wood and then Oil is applied on top. It's kind of moved around with the fingers and worked into the pores. The Oil clears the pumice. I'm using a Danish Oil (with resin content). After 30 minutes I carefully scrape off as much as the excess as possible, working across the grain. Two or three of days later I wet sand and repeat. It doesn't take a lot of sanding. I then repeat the whole thing. I leave it to harden for four days before sanding back and then doing the finish. It isn't as slow as it sounds, actually it's fairly quick but of course the waiting time is long. Colour wise it's worked very well on Walnut.

Michael.N., I know a fellow who applies eggwhite with fine sandpaper. He says it fills wonderfully.

Bob

I know, I've done it many times. It shrinks, just like many pore fillers, so you may have to do two or three applications. Being water based it dries fast and of course egg white dries hard, almost looks like a resin. I'm just not convinced of it's colour with walnut.

In continuing this thread,

What's your method to getting a Mohagany neck to color match an EIR body?

What are the damping drawbacks, if any to a particular method?

Thanks,

-j