Bent Lamination Questions

[Jamie Buxton]

All the walls in that mobile home were full of formaldehyde-laden foam. That was a lot of formaldehyde. For your little lamination job, you'll be using only a few tablespoons of glue, if that much. That's lots lots less formaldehyde.

I do veneering and bent lamination with UF glue on much larger pieces, and am not bothered by it. Put it this way.... Pop open a half-empty gallon can of latex paint, and you'll get a whiff of some chemical brew. That stinks worse, IMO, than the UF glue you'll be using.

[Charlie Plesums]

Charlie, I got the DAP / Weldwood Plastic Resin like you recommended..... The formaldehyde part worries me. What is the stink factor and how long will it linger in the shop ?? Or do I need to do this outdoors ??

I remember when my sister bought a brand new mobile home (25 years ago) the formaldahyde smell was so bad I couldn't stand being in it. Took several weeks for it to finally air out......

The data on that glue is at www.dap.com/product_details.aspx?product_id=42 - I get it from a fellow woodworker who buys in bulk, so I don't have the label other than what is on the web. The instructions say a slight formaldehyde odor, but I use it indoors and don't remember any odor.

The amount of formaldehyde in glue and insulation years ago was huge... this is more like the glue used in plywood these days.

[Tony Falotico]

Well, I got one put together...... slight change in plans, this is for a leg on a table. It is 11 3/4" radius inside, thirteen 1/8" laminations (maple and black walnut) for a thickness of 1-5/8". Spring back was, to my amazement, 0, nada, absolutely none!! It's got several problems to it so it is not going to be usable, but at least I know I can do it. Lessons learned --

• make your forms user and clamp friendly. I tried to do too much at once, didn't plan for good clamping angles
• mix enough glue the first time

I will re-design (re-build) my form to be easier to use and clamp. I need to cut the outside form into pieces and not try to bend the entire thing at once. I will get my glue consistency correct the first time, it makes for easier application. Also, I'm going to review the design, maybe cut back to 7, 9 or 11 layers for a slimmer look.

Bottom line, I'm excited -- I know I can do it successfully, and I can't wait to get started again------

[Charlie Plesums]

... It is 11 3/4" radius inside, thirteen 1/8" laminations (maple and black walnut) for a thickness of 1-5/8". Spring back was, to my amazement, 0, nada, absolutely none!!...Also, I'm going to review the design, maybe cut back to 7, 9 or 11 layers for a slimmer look.

The more laminations, the less the springback. 13 laminations I would expect none. 3 laminations, expect some. So be prepared for possibly a little springback if you do, for example, 7 laminations.

...I need to cut the outside form into pieces and not try to bend the entire thing at once. ...

I don't even use an outside form. Clamp the center to the form, then work out from the center, one clamp at a time, pulling the laminations into the form. If you still want to use pieces of your outside form as you do this, fine, but if "not try to bend the entire thing at once" means some today, more tomorrow, forget it.

[Tony Falotico]

Clamp the center to the form, then work out from the center, one clamp at a time, pulling the laminations into the form. If you still want to use pieces of your outside form as you do this, fine,

That's exactly what I plan to do, cut up and use pieces of my outside form and clamp one piece at a time working my way from the center out. I don't know that I have enough good clamps not to use the outside form piece.

but if "not try to bend the entire thing at once" means some today, more tomorrow, forget it.

No, No, that's not what I meant

Charlie, I really appreciate your comments, help and advise........... please keep 'em coming, Tony.

[Tony Falotico]

These bent lam's are fun....... making legs for a shelving unit, wanted a 2-1/2" bow centered in a 68" chord -- computes to a 240 ft radius. Five ply's, run the formula gives me a 192 ft radius for my form. Calculated offsets for 192 ft radius, comes to 3-13/64" bow in center. So I rounded to 3-1/4", re-computed my offsets every 6" and made my form accordingly and glued up some legs. Let 'em set up, pulled from the form and .. WOW !! 2-9/16" bow in the center.

Had I not rounded I could have been dead on !! Moral of the story ... The equation very accurate !!