flattening a rocking board with a thickness planer

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Forum topic by JesseTutt posted 02-06-2013 08:19 PM 2662 views 0 times favorited 6 replies Add to Favorites Watch
View JesseTutt's profile


854 posts in 2136 days

02-06-2013 08:19 PM

Topic tags/keywords: flatten a board thickness planer remove twist on a board

I have a 6” jointer and a 7” wide board that rocks. The board is hard maple 1 7/8” thick. I need to resaw a 1.00” thick piece from it. Since the board is wider than my jointer I can’t use it.

I was thinking about applying hot melt glue along one side quickly flipping the board over and pressing it onto wax paper. The glue would temporary fill in the gap on the bottom side of the board so it will have a flat (sort of) surface. If I can temporary remove the rock I am hoping that I can run the board through my thickness planer.

Will this work?

-- Jesse, Saint Louis, Missouri

6 replies so far

View BTimmons's profile


2303 posts in 2511 days

#1 posted 02-06-2013 08:23 PM

I’d say place wedges under the board to eliminate the rocking, and hot glue those wedges to a plywood base. It would be a quick and dirty way to duplicate results from a more elaborate and re-useable planer sled like this one.

-- Brian Timmons -

View lumberjoe's profile


2899 posts in 2274 days

#2 posted 02-06-2013 08:25 PM

take the guard off your jointer, send it though and then hand plane the 1”. Or a router plane would work well.


View Tennessee's profile


2873 posts in 2540 days

#3 posted 02-06-2013 08:33 PM

It’s the old argument, you cannot flatten a board with a planer. But if you take very small cuts with the warp up into the cutters, often the rollers will not straighten out the board on a simple bow far enough to defeat the cutter action, and flattening does occur just like on a jointer.
I’d try taking almost razor thin cuts with the middle bow facing up until you reach a flat on that side, then flip it over and with the flat side now down, take off the offending up edges if you want to. It is a whole lot better than wedges, glue, and other bandaids.
Then, you have a at least one flat side you can resaw out the 1” thick plank you need.
Of course, if it is a compound warp, forget it.

-- Tsunami Guitars and Custom Woodworking, Cleveland, TN

View JesseTutt's profile


854 posts in 2136 days

#4 posted 02-06-2013 09:35 PM

Brian, lumberJoe, Paul

Thanks for the replies. I went ahead and tried the hot glue and it worked! When I pressed on the left back the right front only lifted about a 1/16th of an inch. so I just filled that side / edge and along the end with a puddle of hot glue and flipped it over and pressed hard on the back left.

-- Jesse, Saint Louis, Missouri

View ajosephg's profile


1880 posts in 3587 days

#5 posted 02-06-2013 09:46 PM

A fancy sled as referenced by Brian is nice but if you need a quick solution just take a piece of 1/2 inch or thicker plywood slightly wider and longer than your work piece and use it as a temporary sled. Place your work piece on your bench, lay the plywood on top of it and add shims as required so it won’t rock. Then screw the plywood to the work piece in several places. Make sure you countersink the screws deep enough so they don’t protrude above the plywood.
Flip the board/plywood assembly and run it through your planer until it is flat. Remove it from the “sled” and plane the other side.

Obviously you need to pick screw locations that won’t be visible on your finished piece. Also the screw length must be short enough so they won’t get planed.

-- Joe

View pintodeluxe's profile


5705 posts in 2839 days

#6 posted 02-06-2013 09:48 PM

I use a sled jig when planing stock wider than my jointer. The sled is nothing more than a strip of 8” wide plywood, with a cleat attached to one end.
1. start by taking one fairly deep cut at the jointer.
2. place the workpiece (jointed face down) on the sled. Let the rough edge overhang the side of the sled. The cleat should catch the back edge of the workpiece, so the jig and workpiece go through the planer together. Make multiple passes at the planer until you have one flat face.
3. Then remove the workpiece from the jig and plane the other side to the desired thickness.

With a 6” jointer, this technique works well for up to 12” wide boards. No hot glue, screws, or shims required.

-- Willie, Washington "If You Choose Not To Decide, You Still Have Made a Choice" - Rush

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