Originally Posted by
ArchaicArcane
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?
Sorry, I'm not going to be able to get a good picture of this one. I've already started working on it and the appearance has changed dramatically.
You're correct. The ridges between the flat areas were brown.
At first it didn't look too bad. There were dime to quarter sized spots of "good" areas of shellac with little raised ridges in between. The raised ridges were where the edges of the individual flakes of shellac were pushing against each other.
The machine had some really stubborn greasy grungy areas under the motor and a couple other areas. I was using mineral spirits to clean the machine before polishing it. It's supposed to be non-reactive with shellac and I haven't had any issues using it on wood projects. I didn't see any evidence of the mineral spirits disolving the shellac this time either. As soon as I started working with the finish the ridges broke off the old finish and the mineral spirits started lifting off the flakes of shellac where they looked like they were still good. It looks to me that somehow the shellac was just sort of floating on top the base coat, it had somehow lost it's grip.
Even though my machine looked alligatored, I don't think that's what it was. The common form of alligatoring has flat areas of finish with dips in between them and the flat areas are adhered to the base. Mine was the opposite, it had ridges and wasn't adhered.
Now I've got the brown looking little flaky stuff that dead shellac becomes all over the machine and it seems that I'm going to just have to clean it the best that I can and basically give it a new clear coat or 3.
I'm still debating whether I want to french polish the new shellac or spray it on.
I hope this helps,
Rodney