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I am presently finishing 2 new guitars using the Ron Fernandez french polishing video. I am stuck in the filling stage. I have spent about 8 hrs. on each guitar and seem to be making little progress. The materials I am using are pumice, shellac, mineral oil, and de-natured alcohol. I know that this process is supposed to be slow, but I am wondering if I'm doing something wrong.
Does anyone have input on this?
Thanks,
Adam Crom

It is slow, but I assume you had a couple of spit coats of shellac on the guitar first. When filling, you need to work wetter than when you are bodying. The muneca should have dried shellac in it, and the alcohol is applied to the outer cover, 5 or 6 drops at a time and a drop of oil, after applying pumice to the cover. I have found that I have better luck using a pounce for distributing the pumice to the pad. A pounce is a piece of square or round material with a couple of Tbs of pumice in a pile in the middle, the it's gathered and tied. It looks like a muneca, but distributes the pumice very finely and evenly to the muneca when you tap the pounce on the muneca. If I'm not mistaken, Fernandez actually puts pumice on the guitar. I don't like that as much, but it seems to work for him. Work small areas at a time. When you are done, there won't be much shellac left on the guitar. Hopefully most of it will be in the pores mixed with the pumice and wood dust. Think of it as a sanding process, not a polishing process. Polishing comes after filling. You might try some 2F pumice. It cuts a little faster. Woodcraft here had some.

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Waddy

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I am by no means an expert in french polishing. However, I am currently french polishing a guitar under the supervision of a very experienced builder, who has french polished about 180 guitars. So I'll just share what he told me about pore filling. The procedure is a bit different than Waddy's, so I would just try different methods and see what works for you.

When pore filling, he doesn't apply any wash coats of shellac before filling. Just the bare wood. Use a muneca with only pumice and alcohol. No oil, no shellac. Rub it into the pores using small (and slow) circular motions, and apply quite a bit of force (within reason, of course). The idea is to get a kind of paste that has the colour of the wood, that is then worked into the pores. The advantage of not using shellac at this stage, is that any excess pumice is very easy to remove with light sanding. If you use shellac at this stage, the pumice will stick a lot harder, and will be more difficult to remove. If the excess pumice is not removed adequately, it will later show as dark spots on the wood, which may appear to be a feature of the wood, but really aren't.

That said, sometimes when pores are hard to fill, he does use a few drops of shellac on the muneca to make the pumice more sticky. But for example for EIR it shouldn't be necessary.

I tried this method on this guitar, and it works amazingly well. I've also tried applying a wash coat before filling (on another guitar) but in the future I will stick to this method. It worked better, IMHO.

Hope this helps.
Good luck

edit: oh yeah, I had to do two rounds of pore filling to get all the pores to close. After the initial filling, the pumice tends to 'shrink' a bit, so a second session is needed to get all the pores filled.

I don't use 4f anymore for pore filling.
Takes too.... long.
2f much better.

I'm just guessing but, If you don't use a spit coat, I suspect you would end up with pumice in the pores that are not glued together by the shellac.
Don't know. I'll have to try that technique but it seems counterintuitive to me.

To the OP.
I would let the guitar gas out for a day.
Next day go back with only alcohol and pumice.
no shellac.
put the pumice on a piece of paper .
Pick it up with the face of the pad.
Add alcohol directly to the face of the pad over the pumice.
Make sure the pumice has cleared - rub it with your finger to clear and spread.

Apply to surface with a good amount of downward force.
You should hear and feel the pumice grinding against the wood.
As you continue the grinding will get less and less and less until you don't feel or hear it.
Time to reload with pumice and alcohol.
If you don't hear and feel grinding you are waisting your time.

Watch out - when all the pores are filled the back and sides should not be shiny.
You should still see the wood with maybe a slight sheen on it from the rubbing and the left over shellac from the spit coat.

Once you let that session gas out ( half a day after the first session) you can go back and continue filling.
Watch out - If you start to pull the pumice back out you are staying on one area to long.

For a back and sides the previous filling procedure should take you less than half hour.

You might have to do three of four of these but each time there is less work to do.

If you have problems, giving it time to dry and going back later with alcohol is your solution.

Hope that helped.

Waddy

I used to use the pounce but don't like it because I like the coarser particles of the 2f and the pounce, at least mine, only lets the finer particles through.

That makes sense, unless you can find a coarser material for the wrapping of the pounce. I have a salt-shaker for my 2F Pumice.

I also question pore filling without a spit coat. There must be dried shellac in the muneca to provide the binder for the wood fibers and pumice in the pores. There has to be shellac somewhere, otherwise the pores will not stay filled. Pumice is not sticky, nor is oil. I suppose if you use Walnut oil, it would dry eventually, but I wouldn't want to wait for that to happen - weeks! The first time you go back over the area, it'll pull out the fill.

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Waddy

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sad to see there is not more of an open mind to different ways of skinning the same cat. Especially since you haven't tried it (right?). Besides, there is plenty of shellac that will be applied after the filling is done. Try it, you'll be surprised.

Like I said, this isn't coming from me, but from a guy that is a professional luthier, who has built (and french polished) close to 200 guitars that are top notch and sell to a very demanding (professional) clientele. I guess there is some merit to his approach.

I tried that once. I couldn't get the pores to fill at all. It was more like the dust that gets trapped into the pores after sanding. Partially filled at best.
But that was with Walnut. Rosewood and it's rather oily nature though. . .

That is exactly what I would expect. But in order not to step in warmong's toes, I will give it a try and report back.

Warmong

In the mean time. while I try your mentors pore filling technique.
Can you show us a close up picture of the pore filled wood that has no shellac added to it?

That would be very interesting and instructive.
Thanks

Waddy

I had no Idea I could call a salt shaker a pounce, as that is exactly what I use.

You can't, I won't allow it. It's a salt shaker!

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Waddy

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Maarten, I would like to ask you if your teacher used a prepared muneca for pore filling? That would supply some shellac binder.

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Waddy

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It's not like I feel like someone has stepped on my toes, It's just that it seems natural to me to try it before knocking it. But if you have a method that works for you, by all means do stick with it. It's not like I'm on a crusade to get everybody French polishing the way it was shown to me. I just tried to respond to the OP's question with some additional info. That's all.



Hi Waddy, no, the muneca was prepared on the spot. That is, it wasn't prepared at all, just a cotton ball with some old T-shirt cloth over it, to which pumice and alcohol was applied. I was told to add a few drops of shellac to the muneca only if the pumice wouldn't stick in the pores, but this was not the case, so I didn't use any.



I'm sorry, but I didn't take any pictures of the different steps during the french polishing process, and by now there is quite a good coat of shellac applied already. Sorry... However, there is someone else in my class who is currently pore filling his guitar, so I'll try to take a picture of his guitar next lesson. Let's hope he hasn't already started applying shellac.


On the topic of the pounce: yet another unconventional idea (this doesn't come from my teacher, and I haven't tried this myself, but I've seen it demonstrated): I saw someone use a bottle for milk for babies to apply the pumice. He just made some tiny holes in the plastic part (what's it called??) to spread out the pumice. Works amazingly well.

I've just tried this on I.Rosewood. It fills, probably just as quick as when using shellac.
Just need to test how far it sinks back over time.

All good stuff. I'll need to try it too, to satisfy my curiosity. Thanks for posting the method.

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Waddy

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Well, I just tried it and it seems to work at choking the pores.
It is quick and easy.
This seems like a good thing to get the process started.

Maybe you do this first and then a thin wet spit coat application of shellac to soak in?
I'm still concern about the pumice in the pores with out the shellac binder but we will see.
In any case. This just shows that is you use shellac at the beginning, you ought not use a lot.

I have tried some many different pore filling techniques that seem promising at first but show problems later in the process, that I'm always a little skeptical.

Warmong
Can you describe your complete french polishing procedure?
Thanks

sure. The actial FP process is also a little bit different from most other methods I've seen on the internet. My teacher doesn't 'preload' the muneca with shellac, prior to french polishing.
Shellac is applied to the muneca, as well as ethanol, and a tiny amount of oil. Apply by using the traditional motions of FP'ing: circles, figure 8 motions, bigger circles etc. In any case, he urged me to finish every surface with the same motion you start it. Otherwise it would be difficult to get a completely flat surface.

The first few layers are applied with a relatively high amount of shellac (so, pretty wet, but no real 'wash coats' that are applied with a rag soaked in shellac, he starts immediately by applying the shellac with the muneca. This will take a bit longer to get the first coats to the same thickness as you would get by using a wash coat). For the first layers, he doesn't use any oil yet. It is only after 2 or 3 sessions that the muneca will start to stick to the surfacem and only then do we start using oil.
The first layers are applied relatively "wet". As the layers build up, we use less and less shellac in the muneca. Also, I was told to "empty" the muneca towards the end of the bodying session, by adding alcohol, untill the interior of the muneca is white again. so for the last passages, I only add alcohol.
I was told that at any time it is ok to lightly sand the surface (between bodying session) with 400 grit sand paper. When we do very light sanding, we use felt, to which "tripoli" (this is a brick that is ground to a very fine powder) and oil is added.

That is the state which I am in now. For the final polishing we use something we call "popotte", but since I am not there yet, I haven't been told how that works.

Thanks Warmong

Let us know what "popotte" is when you find out.
Also, when you finish, let us know how long it took you to do the whole guitar from start to finish.
Curious.