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View Full Version : Bubbles in Shellac finish??? help...



Matthew Curtis
10-08-2012, 4:22 PM
I have a cherry top that i have put several coats of shellac on. It swas all finished, so I thought. today when I was ready to attach it to the case I saw that it was covered in tiny imperfections that apeared to be created by bubbles. this has now hapened twice. Once on the side of the drawer that for the same project. I sanded it and refinished it.

what is causing this? what is the easy fix?

Patrick McCarthy
10-08-2012, 5:29 PM
are you spraying from an aerosol can? spraying from a gun? rubbing or brushing it on?

Matthew Curtis
10-08-2012, 5:31 PM
brushing with foam pad, as i did on all the other surfaces. it looked good for a couple of days then it did not. All the other surfaces look good and they have been done for a couple of weeks.

Jerry Thompson
10-08-2012, 6:03 PM
If you are going to brush shellac use a Taklon brush.

Matthew Curtis
10-08-2012, 8:13 PM
it looks like hundreds of tiny pitts in the finish

Prashun Patel
10-08-2012, 8:20 PM
This has happened to me before. I believe it is trapped ethanol making its way to the surface too fast. Is happened for me when I put my newly shellacked piece in the hot car. If the piece is allowed to dry at a modest temperature, then after a couple days I believe the solvent escapes slowly and doesn't cause this problem. I am not certain of any of this but Jeff Jewitt theorized this was the case for me a couple yrs ago.

Any other problems with shellac like streaks, white spots, orange peel all manifest quickly after application.

glenn bradley
10-08-2012, 8:21 PM
A pic would help but, I think I hear you saying that when the finish went on it was ok at first but, after a few days developed bubbles(?). Shellac dries quite quickly (in about 30 minutes around here), after that I have never had the finish change on me although I generally apply a 2 lb cut quite thin. Shellac is best used in as thin a coat as will do the job. Are you using many coats of a rich cut? One of the few ways to foul shellac is to use too much, especially per coat. There's my first guess . . . we have some finishing experts on here who will probably shed some light ;-)

Scott Holmes
10-08-2012, 10:45 PM
I too would like you to answer Glenn's question. As he said too much shellac is not a good plan, ever. I think he nailed it. So how many coats of shellac did you apply and what cut did you use?