Woodworking Question

[Cabin Fever]

Any advice on how to deal with 1" boards that are cupped down their length(rough-sawn oak and birch)? Can I cut a slot down the high side of these boards using my table saw? How deep and wide should I make the slot so when I nail the board the cup will bend to "flat?" For severly warped boards, would I be better off making several cuts or use a dado blade to cut a slot?

[milkstoolcowboy]

Cabin,

Is this "old" lumber that is not going to dry further?

Do you expect the cupping is going to come from uneven moisture (inside vs. outside) of board or the arc of the end grain?

Depth on relief cuts for this is usually 1/8", and the other solution is to rip-and-flip, glue back together, but then you no longer have that wide board.

[Cabin Fever]

The boards are dry. I assume that the cupping is due to the grain of the wood. I've never done this before, but 1/8" seems mighty shallow to me. These boards are like iron and a full 1-inch thick.

[ponyboy123]

depending on how u plan on using the boards, you could run them through the planer. Try taking a 16th or even an 8th off both sides, but then bye bye 1 inch boards- hello 3/4.

[milkstoolcowboy]

Relief cuts mainly used to prevent cupping, not fix a board that's already cupped.

You could probably try a deeper, wider cut like a dado, but if the wood's that dry, I'd be worried about how much flex or draw I could get before the board started to split.

You probably want to keep that home-sawed look, so running them through a jointer is probably out.

[Cabin Fever]

Yep, I want to keep the rough-sawn look for my projects. And, I've been thinking about using the boards...as is...for basement wall paneling like those photos OD showed the forum a few days ago. Jointers and planers are not in the picture.

Thanks for the advice!

[uncle Will in In.]

I'd try laying some of them in the sun with the domed side up for a few hours. If it don't help, it won't hurt at least.

[Dahc]

I built my barn out of rough cut cypress that had been as dry as it was going to get. I couldn't get the cup out no matter what I did, so I ripped down the center and made structural boards out of them by liquid nailing them together making a true 2x. Then you can rip the edges straight and clean.

It might be an option for you if your boards are wide enough. Mine were 8-3/8". Also, if you plane the side with the cups lips on it, you can create a flat seat on each side and do a board and batton design. You'll still see the cup but it looks kinda neat. Almost like a half log.

Uncle will had a good idea with putting them in the sun again. I would mist them with water first.

[ricky]

not to much that can be done try the sun lay the boards out with cups out the sun may draw them back may not. if it was me id rip them and or plane one side.

[SouthWesteader]

Yep I always lay boards out to dry in the sun if they are warped. It works even better if you get them wet first.

[Alex]

Cabin,

I am making this up, I haven't done this: how about wetting them down real good, then put weights on them and let them re-dry?

Has that ever been done or worked?

Alex

[Aintlifegrand]

Originally Posted by Alex

Cabin,

I am making this up, I haven't done this: how about wetting them down real good, then put weights on them and let them re-dry?

Has that ever been done or worked?

Alex

I have done that with 2x's and it worked somewhat. They came out better, but some still needed to be kerfed. I would think it might work better with the 1x's..can't hurt.

[CatsPaw]

Generally speaking, a board that is cupped, is the way it wants to be. trying to get them to warp back is probably only temporary. If you do get them to flatten out, chances are after you nail them down they'll warp back.

[bobcarver]

How wide are the boards? You can set up a solar powered steamer by creating a box with a dark metal top. Stack the boards with spacers heavy enough to not bend under pressure. Use several down the length of the boards. Weight it down or use straps to apply pressure (Not too much as it may crack the boards) and add water on a hot sunny day. A few hours later (How many depends on lots of factors) Boards should be flattened. Remove boards and allow to dry and settle still stacked and strapped. Let relax for a couple of days, not in the sun.

I have a 38 inch wide piece of butternut complete with bark on both sides where it was sliced out of the trunk that I will be straightening when we get the farm house to where we can live in it. It'll make a hell of a table.

[Ramblin Wreck]

If I were in the same situation, I would resaw them to remove the cup...but my brother has a sawmill and that's an easy solution for me. Still, it may be something you want to conisider.