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There are a bunch of resent posts on French polishing as of late. I have been responding when I could and when I had pertinent information to share. One area that I may differ with many French polishers is in how and how often I spirit off while boding. so I thought I would share this so that later It would be search able and maybe some help to new French polishers

The MP spiriting off process I have a process


Loading
After the Second full body session I load my muneca with one drop (from an eye dropper) of shellac and allow it to soak in to the muneca well. I add this drop just to be sure the shellac in the inner pad is just a tad wet. Then 6 drops of alcohol and 1 drop of 100% virgin olive oil or my preference walnut oil. I then rub the oil around the muneca and tap on the back of my hand this one drop of oil is to insure that if I have some sticky shellac as I first touch on the body the muneca wont stick.

Stroke
Before I begin I allow the previous body session to cure for at least 1/2 an hour so that only the high ridges will easily melt when I spirit off. I start at the centerline of the guitar of one edge (back or top) and stoke in a sort of firm but not hard straight line towards the opposite edge. I stroke quick but not fast as I want the solvent to melt high ridges left during the previous boding session. I repeat this stroke in the same direction only, over lapping 1/2 the muneca at a time till I reach the edge of the sides. I then repeat for the other half of the back or top. this is the half way point of a spiriting off session on one surface. you will need to reload the muneca as you work with only 6 drops of alcohol and on drop of oil as stated in the loading section.

Once you have spirited off in one direction the entire surface repeat in the opposite direction. meaning if you went from upper bout to lower bout with the grain go from lower bout to upper bout with the grain.

Glide on the surface with out pausing at all. stopping on the body will cause a build up that will need stiffed off after it sets. Glide off the surface the same way. Never stop mid stroke.

The sides are pretty much the same process but work from one edge to the other rather than starting in the middle. It is harder to maintain a firm pressure on the sides with out sticking so lighten up a bit and make more passes.

By following this process after every boding session you should build a level film as you go and not need much leveling before glazing, If any at all.

P.S. this may also help some of you. I always make up two muneca. swapping out every other body session after the second body session. The muneca not used during the previous body session is the one I use to spirit off with. When not in use I store them in a zip lock container to keep the inner pads from drying out. I also change outer pads after about 4 body session or as needed to prevent contamination.


Hope this HelpsMichaelP38974.7509953704

Thanks for taking the time to write up this description Michael, it will come in handy when I start finishing my next one in a few days!

-Mark

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File saved coach Michael, thanks for this, it's really appreciated!

Serge

Thanks, Michael. You helped me immensely with my recent build. I can certainly attest for the need to do frequent and proper spiriting...I didn't do this as often and as a result was faced with some serious leveling at the end.

One thing I might add is to PAINSTAKINGLY make sure that all pores are filled before starting session #1. This requires significantly more attention to pre-finish detailing than any other finish I've tried so far.   

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JJ
Napa, CA
http://www.DonohueGuitars.com

Thanks for the info. I just did a FP on a sapele Grand concert. I've had a lot of positive feedback even though I'm not satisfied. I think that You just made my next one better.

Al

If y'all want to try something that folks in the 1700's would have loved.....

You can "spirit off" using naptha instead of alcohol. The naptha pulls all the poils out, yet doesn't affect the shellac at all. Just soak some paper towels with naptha, and wipe, changing towels often, until you see no oil coming up. You're done. You can stop any time and start againm, you don't have to worry about the pad grabbing and leaving an imprint, etc...

Now, you have an oil-free surface, but it hasn't been leveled off as nicely as spiriting does. So, take out some 800 grit, and block sand it like you would lacquer. After this step, you can spirit off using just a hint of alcohol on a clean pad, to bring the surface to its final sheen, or, you can head to the bufer, and using the same compiunds as you would with lacquer or waterbornes, buff it out to a lacquer-like shine.

All the steps in FP came about in a period where sandpaper and buffers did not exist. If you don't mind cheating a little, the process modernizes beautifully. Give it a shot!

[QUOTE=MichaelP] The sides are pretty much the same process but work from one edge to the other rather than starting in the middle.[/QUOTE]
Michael...Do you mean to wipe cross-grain on the sides?

Thanks for taking the time to write this up. I like your two-pad idea. It makes a lot of sense.

I asm with Mario on the Naptha. After over 20 years of doing it the traditional way with alcohol I read a post elsewhere by Mario about this. I can Sprit off just fine with alcohol but it is so much easier with Naptha I wouldn't go back. I wish I knew about it 25 years ago when first learing

Good tip Mario, i will give this a try tonight and report!

Thanks

Serge

I never said across grain I know it directions can get confusing, go with the grain,

Yes if all you do with your Spiriting off is remove oil Naptha will work fine But I use the spiriting process to level out the ridges as well. That was my main point.MichaelP38975.3696296296

Michael, i guess alcohol could be used as you say to level out the ridges in the first stages and naphta could be used towards the end then, when you want to avoid imprints and just get the oil off?

I see no problem with this. but I would use a muneca dedicated to only for the Naphta.

Thanks again Michael!

Curious: Why do you go in only one direction (upper to lower bout) and then reverse the direction rather than always alternating (like a pendulum, I guess)?

It has to do with pulling the shellac as you melt it. If you went random directions then you would be building new ridges. If your intent is not to melt the ridges as in using Naptha then I don't guess it maters. But if you use my method as both a leveling tool and oil removal going one direction for a complete surface one way and the other direction for the second pass spreads the melted shellac the most even.

Great post Michael..much appreciated. My efforts on the classical got to four body sessions before I got called out to work. Foru weeks marooned out on an oil rig is a rough deal when youve got a half finished FP job sitting at home.