Bent angle

[rslaback]

I'm working on straightening the lid of a cedar chest that my dad had made for my sister back in 1991. He used red elm and the top panel cupped and broke off the ribbon around the edge. Then teenage me sat on the lid and broke the back hinge mount off from the leverage. It is time to remedy my errors, especially now that both of them are gone and the chest sits in my house.

I'm hoping to do most of the cup removal by stripping it and then steaming it back to at least close to flat.

I'm trying to figure out the best way to reinforce it and I think steel would be way better than just a wood ribbon. I'm thinking that if I were to rip down some angle to make some lengths of 1/2" by 2" unequal angle out of 11 gauge that I could hide that steel within a wood ribbon and no one would be the wiser.

I am thinking I need to go with bent angle instead of extruded so that I have a uniform thickness in the 1/2" leg where it will attach to the panel. My local supplier doesn't carry bent angle. Am I likely just better off having the local machine shop with a 12 foot brake bend the pieces for me or is there some magical supplier out there of bent angle?

 

[PCustoms]

In your sketch is "panel" what you're trying to get the cup out of?

The short leg in your angle is doing very little, and you likely don't even need the angle with that tall of a wood stiffener

 

[PCustoms]

Also post this to the woodworking sub forum, you'll get lots of ideas there

 

[Old tool guy]

Don’t even try to straighten the board, all you will do is snap the board in half.

 

[rslaback]

In your sketch is "panel" what you're trying to get the cup out of?

The short leg in your angle is doing very little, and you likely don't even need the angle with that tall of a wood stiffener

Yes. The short leg is just to hold it onto the panel. It would do nearly nothing to actually provide strength no matter how wide it is. Think of it as a nailing fin.

 

[rslaback]

Also post this to the woodworking sub forum, you'll get lots of ideas there

You'd think so but I have tried a few and all I get is crickets.

 

[paulsomlo]

Don’t even try to straighten the board, all you will do is snap the board in half.

Agreed - I think you need to rip it into 5 or 6 pieces along the current glue lines, run each piece through the jointer and planer, then reglue.

 

[rslaback]

Agreed - I think you need to rip it into 5 or 6 pieces along the current glue lines, run each piece through the jointer and planer, then reglue.

I really can't. There is a hand engraving in the center of it. I figure I am not out much if I can't get it to work. It is actually glued correctly with the cups alternating but Red Elm just moves a lot.

 

[PCustoms]

You'd think so but I have tried a few and all I get is crickets.

You've posted here?

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[cgrutt]

Can you cut some reliefs perpendicular across grain on bottom and either install hardwood battens over them or inlay steel c-channel to flatten it out? Attach with screws in elongated holes to allow for seasonal expansion.

ETA c-channel video. I do realize they are starting with a flat top and adding c-channel to prevent cupping but think you may have some success pulling it flat with the relief cuts. Same idea with wood battens but you can mill the battens with a shallow arc to keep tension on ends of top. Good luck.

 

[Old tool guy]

I see joint lines here. Cutting it into 3 pieces squaring the edges and gluing back together won’t be difficult and will go a long way toward straightening the top.

Can you show a picture of how it was attached originally?

 

[rslaback]

Can you cut some reliefs perpendicular across grain on bottom and either install hardwood battens over them or inlay steel c-channel to flatten it out? Attach with screws in elongated holes to allow for seasonal expansion.

ETA c-channel video. I do realize they are starting with a flat top and adding c-channel to prevent cupping but think you may have some success pulling it flat with the relief cuts. Same idea with wood battens but you can mill the battens with a shallow arc to keep tension on ends of top. Good luck.

That is kind of what I am trying to do but since I know this will want to cup again I want to maximize the vertical members as that is what provides the actual strength.