I've read over and over (and believe) that planing finish off boards will dull your knives much more quickly. That said, I don't see why. The planer knives are cutting into the wood under the finish, by the time it pulls the chip I'm betting the knife may not have even touched the finish. So, do it but you may have to sharpen your knives. BTW, shellac is one of the easier finishes to remove with a card scraper.
Vin, like Fred said, I've had success using a card scraper to remove several very old layers of shellac from a chest. When I did it, I wiped on a liberal coat of denatured alcohol, waited a bit, then used the card scraper. It came off relatively fast in a nasty sludgy mess.
Id run it through the planer without much worry. Like Ed said DNA will "melt" the shellac back into a liquid-ish form and should help it come off. I just had to strip down a project with a base coat of shellac and it came off like butter with a handplane and i didnt notice any dulling of my plane iron.
I try not to do too much of such a thing, but I weigh that against the time it takes to do it another way. I don't think it hurts to do this in a limited way.
But yeah, shellac is easily removed with DNA and a scraper.
It will dull your knives faster, absolutely. The planer rotor head is cutting into the top of the finished board as the feed rollers push the board forward. Bits of finish will melt as this happens, sticking to the blade and creating more resistance as the blades cut through, heating up the blade, causing more build up. All of that dulls the blades.
But Jay makes a good point, which is the time saved might make it worth it. For a small board with shellac, go with the DNA and a scraper to remove it. If you're prepping a bunch of reclaimed boards, plane away.
As finishes go, I think shellac is less likely to dull the knives a
lot compared to other finishes. It's pretty soft compared to
things like lacquer and the heavy finishes used in factory
furniture. Shellac can be softened with modest heat…
so putting the boards in the sun under a black tarp or
something like that should cause the shellac to get soft
and gummy. Then you'll find you can get it off with a
paint scraper easily I think.
The alcohol is a good solution too I suppose. I've stripped
french polish that way.
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Related Threads
?
?
?
?
?
LumberJocks Woodworking Forum
2.5M posts
96K members
Since 2006
A forum community dedicated to professional woodworkers and enthusiasts. Come join the discussion about shop safety, wood, carpentry, lumber, finishing, tools, machinery, woodworking related topics, styles, scales, reviews, accessories, classifieds, and more!