Planing question

[imahic]

I have some old pine or fir (not sure which) that has been varnished (I guess is what they did). Is this hard on your planer blades. I know to watch out for nails and such but was just wondering if the old finish would hurt the blades on the planer. Or will the old finish gum up the blades? I just want to plane the old finish off rather than strip it. The wood looks like it might be pretty interesting but is probably harder than my head and chinese arithmetic combined.....

[Beamer]

Yep - it is. Hard enough to worry? I dunno ... i've seen nicks in blades caused by something as minor as the glue in plywood (don't ask why i know...) and other times it's fine.

I think the vertical stuff is worse - if you can take a deep enough cut, you might be able to get away with mostly cutting wood instead of just finish - though, you might get tearout, that way, too.

I would suggest sanding the crap out of it with the roughest grit you have, first - to remove as much as possible. That'll spare you some of the risk on your blades. Though, there might be other considerations with the dust being created by sanding the finish... always trade offs, eh?

[fredbelknap]

I do it but that's not saying that it won't do some damage to your blades. It doesn't seem to bother them very much. Sure beats sanding.

[TDHofstetter]

If it's varnish... you can use a paint stripper to remove it. Saves both your jointer/planer knives AND your lungs (and your stock of 34-grit sandpaper). If it's shellac, it'll come off with denatured alcohol.

[Doug B]

What does a set of planer blades cost? Is it worth that amount in order to avoid sanding or stripping? It would be for me if there is much to do. I've done it a few times and was darn glad I did. And, it did not damage the blades that I noticed. It did feel kinda wrong to do it, but hey, it saved me a bunch of time and that has got to be worth something.

[mduren]

Don't know about varnish but I do know that paint WILL destroy a set of planer blades....

Marv

[imahic]

I might give it a try to see what happens. I just have a couple of boards that are that way and may wait until it warms up some so I can put them outside to strip them. Thanks for the input.

[rnemtp3]

I had some old boards like that and used my hand plane to take off the finish. A lot easier to sharpen that blade. plus since I don't have a power planer and only a palm sander it seemed like the best option. Maybe you could knock of the top by hand then run it through the power one for finish.

[art3427]

Because I prefer salvaged lumber, I quite frequently run into this. I have planed about every paint ever made plus a fair amount of wallpaper off lumber. The trick is to let the knives cut into the wood under the coating. Don't ever try and just remove the film w/out disturbing the wood.

The reason is that cutter steel is cooled by having a sufficient shaving to absorb cutter heat by absorbing it as each flake is severed from the stock. Paints and other films may not be efficient enough in this to keep the knife cool. You'll know if this is a problem when you start getting a film build up on the cutter

Actually, the larger problem is embedded hardware that is hid under the surface. If you plan to use re purposed lumber with any consistency, you would do well to invest in a metal detector. Always check both sides and all edges.

art

[Joe Lyddon]

You also have to be careful about grit (little rocks, etc.) that gets ground into the wood... A good wire brushing helps. ;D

[Leo Voisine]

I have done it.

Didn't notice any ill effects.

[art3427]

I keep a cup brush on my 4.5" disc grinder just to clean old lumber with before I begin any machining. The brush also often brightens tramp metal so it can be more easily seen and removed.

art