Help needed with coopered chair seat. PIC

[Pete Lamberty]

Hi! I am trying to make a coopered chair seat. If you look at the photo you will see that the joints aren't all tight. Most are. I can slide a piece of paper a half inch into one joint. Each edge is cut at two degrees, so when I put two boards together the joint is four degrees. So you have any tips on how to do this correctly? In the next post, I will show a possible solution. Will this work? Any suggestions are appreciated. Thanks, Pete

[Pete Lamberty]

trying again to post photo. It is on the support forum. Can't get it here.

[Pete Lamberty]

Here is a possible solution. Will this work? It has very little clamp pressure on the c clamp. Pete

[Bob Oswin]

This is probably a dumb question at this point but, why didn't you do the glue up in two or more sections?
Personally, I don't think I would try this with more than 3 pieces in the seat.

Not much help but, sometimes it's too late.

Regards

Bob

[Pete Lamberty]

Hi Dr. Bob, That sounds like a possible solution. I would like to get some good ideas before I waste wood on things that don't work. It is just dry clamped in the photos. Has anyone glued just one joint at a time? Does it work? Bye, Pete

[Jim Becker]

Originally posted by Dr. Bob Oswin
This is probably a dumb question at this point but, why didn't you do the glue up in two or more sections?

This is a very good suggestion, as a matter of fact. Small pieces of wood can then be cut to help support the arch when the sub-sections are glued up. Another suggestion is to put a strip of masking tape down the "outside" of the curve befor applying glue. This will keep that edge together as you muck around with the clamping and supporting strips.

[Jim Rahbe]

Pete,

I think you need anti-Bessy clamps….. If I view your pictures correctly, I think the Bessy clamps are trying to do exactly what they were designed to do…..clamp at 90 degrees. I think this is what is causing your frustration. I suggest, like the others, to only clamps two pieces at a time. You might need to make up “fillers” that would go between the Bessys and the glue-up that would adjust for the angle. Not sure if that makes sense or not… you could also try a round dowel between both side of the Bessy and the glue-up that might keep the Bessys from trying to pull together at 90 degrees…

[Pete Lamberty]

Thanks to all of you for your replies. It's hard to see in the photos, but the edges that are up against the Bessey clamps have been cut at an angle. So that when the clamps are tight and the arc is complete, the two end edges are parallel to each other. They are also paralell to the clamps. I don't know if this is the best way, but I will need them to be perpendicular to the horizon when the chair is completed. Jim Becker, you mentioned that you liked Dr. Bob's idea about glueing two at a time. You mentioned putting support pieces in. But I don't understand where. In between the clamp bars and the wood of the arc? This would be just a little space to fill if I just do two at a time. It seems like the joints are extremely tight on the concave side of the arc, and some are slightly open on the convex side of the arc. None are very bad though. What do you think of the C-clamp idea? This really seems to tighten up the joints. I wonder if they will in some way spring open after the clamps are removed. Or perhaps in the distant future. I appreciate all of your thoughts and all others that anyone might give. Thanks, Pete

[Robert Goodwin]

There is an article in this months FWW that shows a coopered door in clamps. The author clamped the door as you did with Bessy's and then used a couple of band clamps to pull the center of the door down. It is hard to describe, but the artivle does a great job....

Good Luck
Rob