Cut shapes through thickness planer?

[Drew Eckhardt]

I don't (yet) have a thickness planer.

I do have 8 (plus spares for when I ruin the next few) 14" x .690" pieces with protruding tapered 3" feet (3/4" thick) which I was planning on using to picture frame the bottom of a (sub-woofer) box using lock-miter joints as-is until I realized I'd only need one lock miter setup if I reduced their thickness to match the 18mm nominal sides they'll be next to.


http://www.sawmillcreek.org/attachment.php?attachmentid=95629&stc=1&d=1219806622

Could I run them through a thickness planer (placing the cut side to the inside of my box so any tear-out doesn't show up?)? I think I need one of those sooner or later (and otherwise like power tools). An MDF scrap with four strips ripped off the end lets me plane with my router in almost reasonable time, but warps in the wood result in thickness variations (+/- 5 mils) which would be noticeable. Would those be less severe with a thickness planer's feed roller squishing the wood against its flat bottom?

http://www.sawmillcreek.org/attachment.php?attachmentid=95630&stc=1&d=1219808606

[David Tiell]

I can't answer your question pertaining to putting cut shapes like this through a planer, as I haven't done that before. But a thickness planer generally will not take any warp/twist out of a board unless you first build a sled to do this. All the planer will do is, as you said, "Squish" the area under the blade against the bed and remove material from the entire width. A jointer works best for flattening the face of a board, but again, I'm not sure about running these shapes across one myself.

[John Eaton]

A sander would work better - build a sled and use small wedges to support the warp then make slight passes - each takes down enough to flatten the board. Flip for the other side without wedges - that should flatten and take care of any warp. The only issue I see here is that those shapes may continue to warp with exposure so this may be a catch 22. You might consider switching the material to something more stable (or is the warp you're mentioning only happening when you use the router?).

-- John

[Charles Lent]

What you want to do is very risky on a planer due to the thin weak center strip and the warping that you describe. If the blades catch the piece will shatter, possibly damaging you and/or the planer. It would be much safer and the outcome quality much better if you used a belt sander. Find someone with one or get a cabinet shop to run them through their sander.

Charley

[Wayne Cannon]

I would definitely run two longer side rails along the sides of your pieces, with your pieces captured (e.g., in notches, with small dowel pins, or similar). I would be concerned that the wide end portions could split at their intersections with the long slender center rail portion, though taking light cuts should help (although the warpage you mention could cause problems if the piece "rocks").

You could always make a "carrier" panel with a recess cut out to fully enclose the pieces you want to plane in order to better support any fragile portions.

I used side rails very successfully for a similar problem -- only because it was quicker to fabricate than a panel with a recess.

[Steve knight]

this would be ok to run directly with a 12" planer. hell I have run 6" long pieces through without issues. slightly skew the pieces if tearout is an issue. but as others have said this won't remove the warp.