Weights when gluing sandwich walls

[Dalorin]

All

Planning to start work on my walls this weekend and I have a question about gluing.

When I glue my exterior 1/4 plywood to the middle wall (the 3/4 frame with insulation in the spaces) can I simply lay both pieces flat on the floor and weigh them down with about twelve cinder blocks evenly distributed? If I do this then I really can't add clamps. I don't know if the weight is sufficient for a glue up.

I plan to use titebond 3 and poly.

By contrast, if I put the walls up on an undersized surface and clamp all around the edges then I really can't add any weight to help the center bond, and I'm worried that the wall would warp.

Thanks in advance.

[KennethW]

Bag and vacuum Even pressure all over.

[tony.latham]

I've done it on three sets of walls using buckets of water and lead and beer. (Yeah, I've got buckets of lead and I used to have some beer.)





It works for me. One could easily win the vacuum bagging argument. I have my 1/4" pneumatic crown stapler locked and loaded and hit it where I feel it's needed while pushing down. I don't think I'd try it without my stapler. Not sure how far 14 cinder blocks will go. (I think I'd rather use water buckets, at least on the internal wall to protect it from getting scratched.)

By the way, those two portable 2 x 8 benches are worth their weight in gold. They sit on folding sawhorses.

Tony

[Dalorin]

Tony, I wouldn't be as worried if I could use my stapler or brads. However, I'm building a woody and I don't want fasteners visible.

I may try to use the trailer frame as my work surface and just make the best of things. Clamp where I can and weight where I can.

There's not much info on the vacuum bag method.

[tony.latham]

Brad did a good job of documenting his vacuum bagging here: viewtopic.php?f=50&t=58223

T

[dales133]

You can pre drill and countersink the internal frame where needed and s rew through to the inner/outer wall part way to hold it

[kayakdlk]

I used some scrap boards with plastic Milk jugs full of sand on top. The boards helped spread the weight around and acted like a larger clamp. I also used a few spring clamps on some of the edges. It seemed to work fine. Do a practice layout with the weights you have and see if you need more. If so scrounge up some books, jugs or buckets of water/sand etc. It should work fine
Dan

[felixx]

I have used welders, car batteries and wheels, buckets of water, beer, boxes of marking (ex teacher) all sorts of things...

the more the better, just use what you have.. if you have a spare sheet of ply to place on top to spread the weight.. even better

[noseoil]

Second the idea of using an extra sheet of plywood for the press. 1/2" OSB works well & is relatively cheap, but anything will work. Just make sure to use enough glue when you stick it together and have as close to a flat surface as possible for the panels when they are weighted down. You might want to consider a few brads to hold things in place before setting the weights in place. Glue has a nasty habit of letting wood slide against itself & having a mis-match of the panel & frame can be a real drag once it sets up.

I'm using Titebond 2 for my build, the 3 isn't really necessary if you do a good job with skinning & waterproofing, but to each his own. I cut the skins bigger than necessary, then trimmed them with a router for the finished cut.