planing twisted boards

[Walt Kenny]

I need to plane a 8" wide piece of poplar down to 5/8 " but it has a slight twist to it and it's to wide for my jointer. I saw a video of a sled a guy made to compensate for such a problem but I wondered if I just use a flat piece under it and skimmed the part that is to high I could get it flat on one side and then plane it down to 5/8" maybe someone with more experience can tell me how to flatten a board as I'm pretty new to woodworking and would like to continue with all my body parts intact

Thanks

[fRED mCnEILL]

Make a sled for the board to sit on for you planer. Then shim the board so it will not rock on the sled. I have used pieces of scrap wood of varying thicknesses to do this. Some people get fancy and build sleds with screws that they sink to different heights to get the same result.Others will use hot glue to keep the shims in place. I haven't found that necessary. What you want is for the board to be stable on the sled so when the planer tries to force the board against the sled your shims prevent this. And put a cleat at one end of the board so it prevents the board from sliding on the sled due to the cutting action of the planer knives. Run it through a number of times until the top of your board is flat and then take the board off the sled and run it through the planer with the flat side down and the board will be planed in the normal fashion.

Make sure that when you fiasten the cleat on the sled you do so in such a way that your knives will not contact the fasteners(i.e. screws or nails) Obviously the cleat should be lower than the board you are planing.

Good luck. Its not difficult to do.

[Loren Hedahl]

Using a sled as above is a good way. I have never bothered to make a planer sled.

Instead I clamp one end down to a flat work bench, then plane down the high spots. My plane of choice is an electric plane; mine is an old Makita. A hand plane will work also. Scrub planes are specifically designed for this.

With a twist you plane some off the high corner on one side of the board, then flip it over, clamp it on the end previously planed and then plane the high side of the other end. This process maintains the maximum thickness available for finished planing and can be repeated as needed.

The objective is to get the twist planed out of the board, not to do a perfectly smooth planing job. Once the board will sit flat on the workbench surface, run it through your lunch box planer taking light cuts on opposite sides successively.

This same process works well enough with rough cut boards that many woodworkers could get along fine without using a jointer. That's not to say that a jointer is unnecessary, just that there is a work around if one isn't available.

[Jamie Buxton]

I take out twist directly on the power planer.

The easy way to do it is to put the workpiece down on the infeed table so that the leading end is flat to the table, and the trailing end is touching only on one corner. Push the board through the cutters, and push the leading end down on the outfeed table, not letting the board twist on the table. You'll take a somewhat triangular cut. Repeat until you have a flat face on the board.

A slightly different approach can result in a thicker board. I put the board down on the infeed table and observe the wobble from the twist. Then I put shims under the trailing end so that the twist is about equal at the leading edge and the trailing edge. That is, both the trailing edge and the leading edge are touching only at the corners, and the opposite corners are off the table by an equal amount. (My shims are old credit cards. They're cheap, and won't damage anything if they get in the wrong place.) Push the workpiece into the cutters, keeping the board's twist controlled at the rear, where the shims are. You'll take a triangular cut near the leading edge. As the board passes on to the outfeed table, press down on that area where the cutters cut. Do not allow the board to rock. Continue the planing pass, still controlling the board at that leading end. Kick the shims out of the way, so they don't go into the cutters. You should see you've cut another triangular face on the board near the trailing edge. Make more passes, keeping those planed areas on the tables, until the whole face is flat.