Subject : Plastic Sheet on Bent Laminations Posted : 2019-03-03 4:59 PM Post #37834
Wondering how to wrap, what will be a rather thick bent lamination using 1/16" veneer, using 3, 4, or 6 mil plastic sheet and hold same in place without sheet overlap and masking tape causing dents in the veneer. I will be simply clamping the lamination to an outside form rather than using a vacuum bag, but still worry about denting the veneer. To avoid springback, I will be using urea resin glue.
Second, would it be safer to leave the lamination clamped until the glue is hard, or can the lamination be unclamped when the glue is rubbery. Obviously, squeezeout would be much easier to scrape off while the glue is rubbery.
Subject : RE: Plastic Sheet on Bent Laminations Posted : 2019-03-03 6:02 PM Post #37835 - In reply to #37834
If you have 1/16" thick veneer, why are you worried about dents? Steam it out or sand it out if it even dents. Or don't use the plastic but maybe wax your cauls. Never really had issues with dents. The last thing I would do is take the clamps off early...
Subject : RE: Plastic Sheet on Bent Laminations Posted : 2019-03-04 11:51 AM Post #37836 - In reply to #37834
If what you want is to have the least amount of spring back possible then let the glue up sit for 24hrs before taking it out of the clamps. Once out of the clamps, find a way to hold it roughly in position for another 24hrs with air flow getting to all sides. Urea glue does not fully cure when wrapped in plastic, hence the second 24hrs to get the residual moisture out. Bent laminations will not hold if you remove the clamps when the glue is rubbery. That is only good for flat unstressed work, like veneering.