Bent lamination question

[johndi]

I'm building Norm's console table. Did a dry run with clamping the rails to the form. When I did the glue up, I could not for the life of me keep the pieces from riding up.

I made some 1" cauls and thought that they were the issue, but it kept happening without them.
Finally had to finish clamping before glue set up. Not sure if it's salvageable.
Anyone have a method for dealing with this?

[cvillewood]

Start clamping in the middle and work your way to the edges. Don't do the whole glue up at once.

[Stwood_]

Not familiar with what plan you have, but for creep...
Very small brad/brads barely drove into one piece, then clip them off real short.
When clamped up, they will embed themselves into the wood pieces.

[rayknight]

Some of the more serious bent laminations I have done used forms with outrigger/rails, which support the lamination stack at the bottom edge, this allows side clamping to avoid/reduce side slippage. obviously use packing tape or wax to avoid your form becoming a permanent part of your treasured piece. I have seen tape cuffs around the ends of the stack (sticky side out, let the laminations slide the way they are supposed to slide as they bend to the form, but control side slipping. and thirdly, dimension stock to accommodate some slippage and joint/saw/rasp/drawknive/spokeshave the errant laminations back to the herd. 
Ray Knight

[johndi]

Thanks for the replies.
I'm going to try the tape cuff on the second one.

[johndi]

Ray, thanks for mentioning outriggers. Gave me an idea. I moved the base of the form so it canteleivered over the end of the bench, and used my biggest C clamps to push the tops of the pieces into alignment as I clamped the curve.
No I just hope I didn't introduce a twist?

[atgcpaul]

I would try to incorporate a top edge so they can't ride up. I think that's been suggested. You may also check that the back and front of your clamp faces are parallel or try to have the clamp at a slight angle such that it pulls the top laminate downwards when you tighten it.

[handi]

I learned laminating curved parts making spiral staircases, and episodes 3-4 of my show will feature a Library Stand with bent wood laminations. (Episode 3 available in early August)

I mill my strips at least 1/8" wider than the final width of the parts, more as the stack gets larger.

I use stretch wrap to "Clamp" the stack together once the glue is added. I wrap the ends on all stacks and maybe one or two spots along the length for longer glue ups. 

This tends to keep things mostly aligned during glue up, but you ALWAYS must plan on the layers skewing a bit, which is why you leave things wide and mill down after gluing.

[ez-duzit]

...you ALWAYS must plan on the layers skewing a bit, which is why you leave things wide and mill down after gluing.

This, for sure. Also, while I'm applying clamps, I hammer down the edges of the laminations using a scrap wood block to get them back into alignment.

[WilliamHodge]

Try  ratcheting truck straps instead of clamps. Pad the straps with a few extra laminations without glue, but wax, on them.