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Spiriting off French Polish is traditionally done with alcohol. Some people
however use Naphtha for spiriting off, the argument being that theres
less chance of removing the body coats in the process.

Comments from OLF'ers would be welcome on this one

Cheers and TIA

martin

I've done it. It gets the oil off very well and it is easy. Often, there will be dull spots right next to shinny spots when you are done and those regions were all shinny when the oil was still on. Some people say the spiriting off is an integral part of the French polish process and that it makes the resulting finish harder and naptha won't do that for you. I don't know if they are right about that or not.

The job that spiriting off does in the traditional format of French polish is basically three fold

1. removes the oil used in bodying sessions
2. levels the film and compresses the solids tight aginst each other
3. polishes the film

If your solvent agent like naphtha, will not melt the shellac then two of the three tasks can not be accomplished. And in my opinion those are more important tasks in the long run.
MichaelP38854.4461805556

Don't take this personally but imo the only reason to use naphtha vs. alcohol is that you (meaning the person doing the task) is having problems with removing the film in areas. This is lack of technique mastery and show a need for more skill development. I’m not getting on to anybody here just stating that if the proper technique is learned then this is not an issue.

A short little tutorial on how I spirit off and the keys to not pulling of shellac.

First and foremost keep in the back of your mind that by adding alcohol to the pad ( the muneca) is that you are cutting the residual shellac in the inner pad , not flooding the pad with alcohol. You want the muneca to be just barely wetter than if you were boding.

Next the stoke should be with the grain. This will lessen somewhat the tendency to pull off shellac. Also the force of the stoke should be firm but the motion quick. So it is a compromise between how hard you press and the ability to stoke quick and constant in a straight line without sticking or dragging.

I find it helps to keep in mind the purpose of spiriting off. During the building of the film stages it is mainly two fold. It is to remove residual oil and to level the last body session. During this stage less pressure and a slower stroke than in glazing is required and the film should not be over worked. This one of the biggest cause of film removal (over working). Be sure to keep your muneca properly loaded. Too dry and you stick thereby removing film and to wet over melting the film thereby removing film. We just want to barley melt the high ridges of the previous body session. (I hate the word layer when referring to French polish because you are actually build a single amalgamation of shellac not stacked layers)

In polishing out or otherwise known as glazing you want to load just a single drop of oil to the muneca this to aid friction resistance and spread it around on the muneca face. Use more pressure and faster strokes. This is like buffing shoes polish and is a process that is accumulative. The glosser you want the surface the more glazing required. Here again keeping the muneca properly loaded is key

In both types of spiriting you need to glide onto the starting edge and glide off of the trailing edge in a smooth constant no hesitating motion. This motion is an other key to not removing film

Michael, I've FP'ed four instruments and there are still a few things in the process that I haven't been able to reconcile with the reality.

1. How do you glide onto the starting edge and glide off of the trailing edge when you are working on the joint between the neck and the body on a classical? My instruments, so far, have had removable necks and this hasn't been a problem but I wonder about it.

2. How do you do the insides of a slotted head? I would find it very hard to keep the pad moving in such a confined space.

Every demonstration of FP I've seen has done either a top or a back. I usually have no problems with that. It's nice and flat and easy to do or fix if you get into trouble. It's the little corners and irregular shapes that are the headaches.

Yep those are the problem areas. A much lighter touch and the best you can is the only real answer I can give you there. Just like boding in inside corners you have to shape your muneca to fit the joint and you will need to reshape by pinching as you work. I don't build classical spanish heel necks so I don't have this issue but just like a dresser drawers you have inside corners to deal with. It is slower and more tedious in these areas.

Slotted pegheads I dont build much of a film depth in the slot and am not too worried about perfect film on the edges of the slots. I still want it nice but one or three body sessions there is enough and a quick wipe with a near dry Alcohol load will do the trick removing oil. I don't glaze there till the very end and then I only glaze in the tappered section nearest the nut so the sheen blends. everyone needs to work out techniques that work for them in the problem areas. but know how the process works is the key to addapting in these areas. Sorry I was not better help here MichaelP38854.7090393519

Thanks guys....excellent feedback to my query.

Cheers

I build classicals, and I FP them. I find the biggest problem area for me is getting the sides right next to the heel to look decent. What I've started doing is, instead of using a muneca there, to instead fold over a piece of T-shirt material a few times such that it's more or less a flat square or rectangle, add shellac to it, and wipe down the area, several applications to build up a decent film thickness. Then I use 1500 grit Micromesh and lightly sand down the "ridges." After that I use progressively finer grits of Micromess to 12000, then buff things out with a good polishing cream (I use the stuff that comes in the Micromesh sample kit for this).

For the tuner slots I use Q-tips. Once again, several applications, and then I run sheets of Micromesh through the slots to smooth things down. Like Michael, I don't worry too much about getting things to shine in the slots.

Best,

Michael

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