there isn't a whole lot of difference between "tar" and what SM mfrs dipped the machines in to make em black. I think it was asphaltum based.

The old Japan finishes were basically a baked on varnish with asphaltum as the coloring agent.
It looks to me like you're stripping off the old shellac.
The 99 I'm working on for my daughter has a very badly damaged shellac clear coat. Most of it is going to come off whether I like it or not. The machine didn't look too bad at first, just some alligatoring is what I thought. It turns out the entire coat of shellac was basically floating on top of the black. It's a pretty big mess at the moment. I figure I'm better off taking it off as gently as I can and then I'll either wipe or spray on a fresh coat.
Rodney

I still get amazed at what the really bad shellac will do when you work with the French polishing.
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That is one cute inspector.....

Yes, shellac turns a weird powdery brown when it fails. The alligator flakes on Rodney's machine were likely brown around the edges... I also have a machine here that the shellac has failed on and it's got that brown powdery film on it. I may take it on one day, but it's a real project and not a machine I've bonded with (about a 1920s 99 that requires massive electrical, mechanical and appearance work.)

Rodney, I was once looking for a good photo of an alligatored machine and had no success. You don't happen to have one, or the willingness to make one, would you?

the sewing oil (or mineral oil) brisk rubbing and a soft rag, eventually softens up and sort of re hydrates the yellowed shellac. If you add a teeny spot of alcohol, it will melt the shellac quicker. That's what shellac thinner is, alcohol. The thing is, you can damage some decals so easily. I haven't tried Bug and Tar remover, yet. What does it smell like? Kerosene?

The bug and tar remover I used seemed to have a masking odor of pine. I use it on the non black machines with good results. I'm not sure of the all black machines but I did use it on one - nothing else worked and the machine was toasted anyway... (works now) Ask Glenn when he gets back from wandering around Texas.

I spend a lot of time rubbing away old shellac in front of the TV after a hard day at the factory. Baby oil, mineral oil, sewing machine oil, basically all names for the same thing, with a soft cloth, and rub so fast it gets hot and squeeks, when it squeeks the old shellac is letting go.
In the old days we removed tar with kerosene. And polished the paint on VW bugs...

I've used the Bug and Tar remover on all of my machines from the plastic to the old iron ladies and it works very well. It says it will not remove wax and is made for clear coats, apparently shellac is not included...

As far as fumes the smell isn't bad but I have to wear a paint mask when using it or it wreaks havoc on my sinuses and I get a bad headache.

Best used outdoors or with a workbench exhaust system if you are sensitive

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