Millling longer lumber using a planer sled

[Brian Runau]

Newbie at this still learning. I am m,ill some lumber for a 3/4" x 30" x 84" top. Couple pieces at bowed like this. I like to leave 3" to 4" extra for snipe etc... To reduce the bow, would you cut it down to say 88" from one end of equal amounts off either end, assuming to splits etc on the ends. thanks.

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[Eric Myket]

At that final size, I think I'd want the top to be thicker than 3/4" just for visual balance if nothing else. If you're intending to joint out that bow entirely, you'll end up right at or slightly under 3/4. You could cut down to final length before jointing, but as you said, you may run into snipe. Across a distance of 7 ft, I'd be more inclined to use neighboring boards to straighten out the bow, i.e., use biscuits/Dominos/etc. to align and flip the bowed boards end for end so that their bows cancel out when glued up.

[Randy Heinemann]

Using Dominos to line up the visible face is a great idea but you have to be sure you have enough thickness to get rid of any final uneven joint sections. Unless you know someone who has a 30” belt sander or planer this is sometimes more difficult than it sounds even using Dominos for alignment.

[Maurice Mcmurry]

If I am understanding correctly the problem is getting rid of a twist or cup in a long board?
After figuring out where the worst twist is, cut that part off. This is one problem where I use a hand plane for before thinking of a machine. My jointer is not long enough and I have not made a long planer sled. I knock the two opposing high corners down with a plane or hand held power plane. A way to figure out when I have gotten long wood close to flat remains illusive, eyeball, long level, and how the boards meet when laid together are what I look at. When I think I have one side flat I start making passes on the planer to flatten the other side and hope there is enough thickness left. If the improved boards do not lay nice and flat unclamped, without any forcing, I don't use them.

[Mel Fulks]

When a board is wider than a jointer you can put it on the best flat surface ,and glue some wood strips and blocks .to make assembly non
rocking . Then send it through the planer til” mostly flat …then flip it over , remove blocks and plane again .

[Brian Runau]

Ok. I am still struggling doing this. I have a grizzly G0586 8" x 75" bed on it. I set up infeed outfeed support rollers. I am now milling a 7-1/2" wide x 86" long piece of cherry. Had a bow end to end. Using my jointer, I began milling it. As expected it is taking material off of both ends to lower the bow. I am down to 13?16" on either end at this point. Still a bow and I am reluctant to continue milling on the same side. Concerned once I get a side flat, there won't be anything left to mill the opposite side. This goes with other pieces into a 30" x 84" table top. Working with 3ft or 4ft piece this level of bow is not normally an issue since I cut it into smaller sections.

Picture shows the gap at this stage of milling it. 1/8" bow, but only 1/16" material to be removed on either end.

Any way to salvage this piece of lumber?

Thanks. Brian

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[James Jayko]

I think I'd try to domino / biscuit / spline it as is. If you have two boards cupping opposite directions, put one cup side up and one down. That's just too much bow to plane out if you want to keep 3/4"+...

[Brian Runau]

I think I'd try to domino / biscuit / spline it as is. If you have two boards cupping opposite directions, put one cup side up and one down. That's just too much bow to plane out if you want to keep 3/4"+...

Ok, but do I take one side down so it is jointed or planed smooth first? Bottom can be rougher, but on the 1" overhang. I can clean that up with a hand plane or ros, I guess.

[Michael Burnside]

Ok, but do I take one side down so it is jointed or planed smooth first? Bottom can be rougher, but on the 1" overhang. I can clean that up with a hand plane or ros, I guess.

I'm with James on this. Don't mill the board any further beyond matching the thickness of other boards. Then, just place it between two boards that are flat, use your domino or biscuit jointer so that it references the tops of the boards. The two flat boards+dominos on either side will pull the slightly bowed board into line and the glue will hold it there long term. I've actually seen this done a time or two, but I've never had to do it personally.

I recommend that next time you start with 6/4 lumber, at a minimum, for any tabletop in the future.

[James Jayko]

If it were me, and you have one good face so far, I'd do the glue up first and then come back with planes or a ROS. If not, I'd skip plane it in the planer. You could always skin the bottom if you wanted to make up for missing thickness (I think you said you wanted 1" to begin with?) Only if you have an extra piece, tho...

[Maurice Mcmurry]

I need to have the bottom flat and true so the boards lay in the bed of clamps without any rocking. Then I work on the edges, putting the bottom against the jointer fence. When the bottom lays flat and the edges all meet, and the assembly continues to stay flat when a little clamp pressure is applied, I flip the boards over and put in the biscuit slots (referencing the bottom). Glue it all up, or glue up sections, then flatten the top. When I say top and bottom I refer to how it will go into the clamps. Chose the side you like best to be the surface. Beware of iron stains from squeezing-out contacting clamps. I lay a piece of box tape over the clamp, under the joint.

[Brian Runau]

I'm with James on this. Don't mill the board any further beyond matching the thickness of other boards. Then, just place it between two boards that are flat, use your domino or biscuit jointer so that it references the tops of the boards. The two flat boards+dominos on either side will pull the slightly bowed board into line and the glue will hold it there long term. I've actually seen this done a time or two, but I've never had to do it personally.

I recommend that next time you start with 6/4 lumber, at a minimum, for any tabletop in the future.

Michael, I agree my error, never having done this before, was not using thicker lumber in the beginning. Thanks brian

[Michael Burnside]

No worries mate, we’ve all been there. My first drawer fronts I ever did were too thin and I had to start over.

[Brian Runau]

No worries mate, we’ve all been there. My first drawer fronts I ever did were too thin and I had to start over.

So with the piece of lumber I have, at this point in an attempt to see if I can make it usable, would you suggest I flatten one side using the planer sled or just take the partially flattened side down and send it through the planet without using the sled to see if I can get a milled side and hold the 3/4" thickness? thanks Brian

[Robert Hazelwood]

Ok. I am still struggling doing this. I have a grizzly G0586 8" x 75" bed on it. I set up infeed outfeed support rollers. I am now milling a 7-1/2" wide x 86" long piece of cherry. Had a bow end to end. Using my jointer, I began milling it. As expected it is taking material off of both ends to lower the bow. I am down to 13?16" on either end at this point. Still a bow and I am reluctant to continue milling on the same side. Concerned once I get a side flat, there won't be anything left to mill the opposite side. This goes with other pieces into a 30" x 84" table top. Working with 3ft or 4ft piece this level of bow is not normally an issue since I cut it into smaller sections.

Picture shows the gap at this stage of milling it. 1/8" bow, but only 1/16" material to be removed on either end.

Any way to salvage this piece of lumber?

Thanks. Brian



Maybe too late now, but I like to remove material from the convex side first when flattening out a bow. So your jointer passes would be taking wood off in the middle and not at the ends...but only remove a little bit in one session. Often enough this will make the board relax a bit and become straighter. If that happens then you can flatten it without removing as much material.

[Robert Hazelwood]

So with the piece of lumber I have, at this point in an attempt to see if I can make it usable, would you suggest I flatten one side using the planer sled or just take the partially flattened side down and send it through the planet without using the sled to see if I can get a milled side and hold the 3/4" thickness? thanks Brian

Depends, I'm not sure how much thickness you have left to work with. At some point you'll make it thinner than the other boards and then those will have to get planed down too. If you're at that point then I would just run it through the planer with your mostly-flattened side down and take some material off the convex side. You might find the board straightens out some on its own when you do that. If not then just skip plane until it matches the other boards in thickness and leave the bow. In long 3/4" material that bow should clamp out easily for glue-up. It will be held straight by the other boards and by whatever you are fastening the top down to, so I think you are likely to come out alright if you can't get all of that bow out.

[Mel Fulks]

I would remove wood from the convex side , that often makes the board straighter on both sides .

[lou Brava]

Not exactly sure, but if your board has a planed surface and ready for glue up except the problem is a bow and planing the bow out will render the board to thin. Than I'd just choose bottom and cut 3 relief kerfs across the bottom face of the board maybe 1/4" or a bit deeper. This will allow the board to lay reasonably flat and you will have no problem getting the top to flush up with your straight boards during glue up. I've done this few times on 8' long 5/4 stock.

[Randy Heinemann]

I just had a similar experience with 6' quarter sawn oak. I ended up using Dominos to get the boards to line up on one side. This was after attempting to plane the ends to get rid of the bow. I wish I had just used Dominos before trying to flatten one side. I would have had more wood to work with. In the end I got a final table top of 11/16" instead of 3/4" which I think will still work (hopefully considering there is about $200 worth of quarter sawn oak in the top. Next time I will just attempt to use Dominos to get the side I plan to use for the visible top, get them joined, and then flatten them. Unfortunately I think this only works if they aren't all cupped end to end (which mine weren't).

Also, a drum sander is sometimes more useful with this situation as it's main function is to flatten. It takes awhile, but it does work better than a planer or jointer sometimes.