Robert O'Brien's online French polish class

[Kyle Barbour]

To keep from hijacking Johns build and turning into a review of obriens online course I thought it would be best to start a thread here.
As was mentioned before, the class is not just a quick demonstration of a French polish technique, but a course on teaching his method. One that works quite well. There are alot of details covered, from finish prep and pore fill to polishing and spiriting off. One of the key elements for me on this process was how dry of an application this is. He does a great job showing how the shellac vapors off quickly behind the muneca. The pad should almost feel dry to the touch leaving just a thin coat of shellac on the surface. It does take longer to build up this way, but saves time at the end when your concerned about the level of the finish.
There's plenty of details to add to this thread. I figure this can be a starting point for those who want to add to it. I'll try to add more as I get time and think of some more key points.

[John Link]

Kyle,

I have a question. Does O'Brien cover the difference between filling the pores with epoxy first, then applying FP, versus filling them with FP and pumice as one goes along?

I have not tired the epoxy pre-fill, but theoretically it strikes me as a way to fill large pores, as found in BRW, with a non-shrinking transparent material that would level them with the rest of the wood before applying the FP, which does shrink over time. (Shrinking is good, as far as sound is concerned, I believe; it is just not so good for appearance when pores are involved.)

Thanks.

[Kyle Barbour]

I don't recall him saying much about using epoxy as a pore filler. In the course i believe he uses tinted drywall compound. I used zpoxy to pore fill and was happy with the results.

[John Parchem]

Yes Robbie used black dyed drywall compound., I use z-poxy. After the pore fill I do follow Robbie's French polish technique. I posted this in a different thread but this is basically the process contained in the course.

After I pore fill the instrument on the back, sides and neck (I use between 2 or three sessions of zpoxy ) I give the whole guitar about three thin padded on coats of 1lb cut amber shellac that I make from LMIs blond or amber flakes.

What I will describe is bodying (or as Robbie calls it polishing) and spiriting off.

My pad (muneca) is a 4"x4" high thread count white cotton strip. I use lambs wool as stuffing, others use cotton or wool knit. I believe Robbie used cotton, Cyndy Burton uses wool felt.

I start applying body coats with the same 1 lb cut of shellac. I put about 6 "sessions" worth of polishing on during the bodying stage. You can do more or less. Each session for me following Robbie's technique includes charging the inside wad in my muneca. I actually dunk a wad of lambs wool in the shellac and squeeze most of it out. I place the wad in a 4 x 4 piece of cotton. Fold and twist until I can get a little shellac to squeeze out. I back off the twist a bit and blot the muneca off as I do not want anything resembling a drop or drip. For each session I start by lightly applying the shellac with long ways (with the grain) strokes. I keep applying until things get a little sticky. At that point I put a drop of oil (I use olive oil) on the muneca and use small swirls to cover the surface I am working on, usually a few times around the surface I am polishing. As the pad dries out and it is harder to swirl, I get rid of the swirls with relatively hard long ways strokes until the surface looks pretty good and there are no swirls and very few streaks. Through all of this the pad should not stop on the guitar. Also when doing the long strokes pretend you’re an airplane coming in for a smooth landing; bumping the edge with a charged muneca can ruin your day with a drip on the adjacent surface. While the pad is moving on the guitar you should never see any pools of finish rather a quickly evaporating tail following the pad.

After enough bodying sessions (6 or so for me) I spirit off the polish. The pad is charged with only alcohol (either DA or 190 proof everclear); I dunk a wad of lambs wool in the alcohol and squeeze most of it out and place it back in the cloth. Not so much that it will drip. I do long strokes with the grain, very gently and evenly across the instrument surface until the pads starts drying out. As it is drying out I am applying more and more pressure burnishing the finish. I watch the alcohol evaporation trail to know when I should apply more pressure and when the pad is dried out. I do this about three times. I basically do this until I am happy with the look. At the end of this process if not completely happy there is no problem doing more bodying (polishing) sessions.

While working if it gets hard to do a session or the finish seems soft, just leave it for the day or at least a few hours.

[John Link]

Thanks guys.

Epoxy is much more appealing than dry wall compound. You can choose between tinted or clear, it is stronger, sticks better, and is probably more inert once catalyzed. But then the old fashioned filler so many of us used under nitro may not have been much different than dry wall compound, and it has stood the test of time pretty well.

The most appealing aspect of epoxy is its clarity option.

[Harold in Tn]

I had some shellac flakes for a couple of years and I am having trouble getting them to dissolve in grain alcohol. Do they go bad after a time??

[John Link]

Mine never go bad. Perhaps yours will work if you soak them long enough.