Official Luthiers Forum!

I have a question about the cuts of shellac you are to use when French Polishing. I have read the Milburn article and watched the Fernandez video on French Polishing.

When bodying, it looks like you squirt some 2 lb cut into your muneca following by an equal amount of Denatured Alcohol. Essentially, this makes a 1 lb cut. Generally, 6 – 8 sessions are applied.

When glazing, which follows bodying, Milburn says to use a “thin glazing cut of shellac by simply adding several parts of alcohol to 1 part of shellac. Install a clean muneca cover and add a few drops (about 3 or 4 drops) of the 2 pound shellac. Add an equal amount of alcohol to the muneca and a drop of olive oil.”

I don’t see any difference in the cut between bodying and glazing.

Can someone give me the cuts that I am to use for French Polishing? If it is straight forward, why not just mix the proper cut containers. This way you don’t have to add alcohol. Just squirt and go.

Thanks,

Doug Ubele

_________________
Guitars...One's too many...Twenty is not enough.

Having fun yet Doug

If properly read Milbun's say you..CAN..cut the 2 lb cut of shellac by doubleling the ratio of alcohol to shellac you add to your muneca. i.e. if during boding you were adding 10 drops of shellac and 5 drops of alcohol, you now must add an additional 10 drops of alcohol to cut the 2# cut to a 1# cut. This is personal prefrence. I prefer to make seperate cuts and label the bottels as such. Either way while glazing you use half the ratio of pure shellac to alcohol that you used in a body session

You will always have to add alcohol as you pad because the alcohol evaporates so quickly as it is exposed to air. Also the alcohol that you add to the pad just before boding is there to melt the prelaid film to accept the new shellac, not to cut the shellac in the inner pad. If you did not add alcohol to the outer pad just before padding the prelaid film would not amalglamate properly with the newly applied shellac.

For this same reason you should only mix up enough cut shellac for the project at hand. If you try to shelf the cut shellac for long periods of time the alcohol evaporats out and you no longer have consistant cuts.

the porpose of the thin cut at glazing is to compact and polish the film with out pulling off the film. The thin cut of shellac inables this processMichaelP38453.4692013889

I don't think I have mentiond this to you before, As I stated in my last post that you can't shelf cut shellac for long. This is the reason you can't find but one retail pre cut pre canned shellac pure enough to french polish instruments with.

That One is Zinner's Sanding Sealer. I don't know how they pulled it off but it is good stuff. Pre cut to 2# straight from the can. It is a very small bit amber as conpaired to extra blond made up fresh. But very very little. I use it exclusively now. Out of 5 quarts I have used I have never had a bad batch. Zinner's also now makes a pre botteled French polish mix that has the oil add. It is good as well but I prefer to add my own oil.

Just thought you might like to know.MichaelP38453.4747685185

Hi Michael. I'm having a great time! It's going good except for the dreaded glued down bridge. I'll have better luck next time as I have learned a lot. I just finished my 5th bodying sessions and may stop there. It depends on what you think of my process below.

Let me ask this another way.

What do you do for Bodying?
Here's what I have been doing. I have 2 lb shellac in a squirt bottle. I have DA in another bottle. I squirt some 2 lb cut into the pad. I then squirt a slightly less amount of DA into the pad. I smack it. Blot it. Add a drop of oil.

What do you do for Bodying?
I was planning on doing what I do above, but use a 1 lb. cut.

Thanks,

Doug Ubele

_________________
Guitars...One's too many...Twenty is not enough.

I use an eye droper to dispence with. For bodying I load with typicaly 6 drops of 2#, 3 drops of alcohol and 2 drops of oil. I adjust based on how the film is building and how the pad is gliding an the work.

Galzing I load with 4 drops of 1#, 8 drops of alcohol and 1 drop of oil. Keeping in mind that the inner pad has a bunch of shellac already in it. I will decrease the amount of alcohol I use while glazing by 1 drop every glazing session. because the shellac in the inner pad becomes thinner as you go.

notice I am reversing the ratio ...Bodying = 2 part shellac to 1 part alcohol...Glazing 1 part shellac to 2 parts alcohol
You will get the hang of it as you go along. You will refine you processes a bit with each guitar you finish. At some point along the way you will pay more attention to how the film is developing rather than the ratio of your load and find yourself adjusting instintively I could give you my exact process but you would not be able to reproduce it because you touch (for lack of a better term) is not the same as mine.

This make sence?

Makes sense. Thanks Michael. I think I will move on to glazing. What do you think? I have bodied 5 times and it looks like I have a good build. I will first sand with 1500.

By the way, what's your inner core made out of? I'm back to cheese cloth. I tried raw lambs wool, but the individual hairs kept coming though the outer cloth and sticking to my guitar. I would love to try wool socks, but can't find them anywhere.

Thanks,

Doug

_________________
Guitars...One's too many...Twenty is not enough.

It all depends on how deep you want the finish to appear. Five may be enough. That will be your call. You will have a better Idea on the next one.

My inner pad is 100% pure undyed woven wool cut from a new hunting sock. That is the only 100% undyed woven wool I can find in these parts. If you try this make sure that the sock is 100% wool and undyded.

I would suspect that raw unwoven wool would migrate through the cotton. Cheese cloth will work fine but the wool I feel is best at standing up though the job. And imo the flow is better.MichaelP38453.6766782407

Doug check your PM