Witness Lines from Shellac Application
Advice on hand-applying and sanding shellac in combination with transtint dyes and linseed oil. July 7, 2011
I applied a coat of Transtint dye to my birdseye curly maple table top and then sanded to bare wood, applied another coat of a different color dye, and let those dry. I then applied a coat of linseed oil, gave that time to dry, applied a coat of sealcoat, and sanded that down till it was all dull without sheen. I topped it off with a few coats of amber bullseye. Every coat I put on, I'm getting witness lines that I need to sand back down, but each time I do, I'm sanding in some spots to bare wood. I can't get rid of the lines if I don't. I tried thinning the stuff because I know it has wax, but I don't know much about it. I've had to apply more dye to the spots that I am making by sanding to bare wood. All I want to do is get this stuff to enough coats where I can sand it even without going through the color so I can apply a coat of paste wax. I need help. I hate shellac.
From contributor R:
You don't mention how you are applying it. Shellac dries very fast. If you are brushing, you need a good brush such as ox hair and you have to work fast to lay down a wet coat without going back over it or tipping off.
I'm pretty sure the Bullseye is a 3lb cut, which is too heavy. I have found a 2lb works well for brushing and padding.
I would also recommend mixing your own. Zinsser claims a shelf life of 3 years, but I would not stake my work on it. Buy the flakes and mix just what you need.
A great way to apply it, particularly to a table top, is to pad it on. Unlike dewaxed, the waxy stuff sands easily so I'm not sure why you have to take it back to bare wood. I would recommend you mix a fresh two lb cut of the waxy shellac and pad it on (there are plenty of articles on the web on this subject).
From contributor N:
Brushing the Bullseye shellac is almost impossible to do on a large surface without getting overlapping. I would reduce with denatured alcohol and spray it, or you could get a shellac retarder from shellac.net and try that.
From contributor B:
What kind of witness lines? Brush strokes or sanding strokes?
From the original questioner:
I am brushing, and when a coat has dried, I see lines that look like I spilled it on and it dried that way (like a puddle). When I sand the puddle lines away, I sometimes go through the finish.
From contributor B:
It sounds like you've sanded through, recoated, blended back what have you, and you're seeing through the shellac the uneven buildup of your finish schedule. My advice - sand it all the way back and start over. It sounds like it's a beautiful piece of wood. If I had to guess you probably went through the seal coat and the shellac highlighted it. Why are you even using the seal coat? You just shellac right on top of the linseed.
Shellac and Linseed Oil Finishes
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