I'm planning to do some large veneer layups on particle or mdf and am thinking of using clamping cauls instead of vacuum. Any ideas or comments on spacing of cauls and achieving enough even pressure. I plan to have the veneer and substrate sandwiched between 3/4 mdf and then the cauls. I'm not sure how many are needed on a 6' piece. Any suggestions. Thanks.
From contributor Th
If you're only using 1 sheet of mdf on each face of your panel you want to space 2" cauls 2" apart. You may want to do research beyond posting here. Good Luck.
From contributor ch
Thanks. I was thinking around 4-5" would be fine but I'll have to look into it more. I've seen guys on Youtube and the Bowclamp used with quite a bit of space between, but you never know. Seems like others would lay up like this one in awhile when a vacuum press won't work, but maybe not. I guess I could experiment too.
From contributor Bo
Why not use a vacuum, more consistent and no real question about how to clamp it properly. You can make a bag of virtually any size and the cost should be less than what you will pay in time to make a bunch of cauls.
Bob
From contributor ch
Thanks. The vacuum really is a great way to go. Yet on this project I will have 5 x 7 panels to glue up. The bags I found at that size were 4-500 bucks. Seems crazy. This piece will also have a seamless waterfall veneered side. I don't have a sliding tablesaw that can cut a 45 mitre at 5' long to achieve that look. So the only way I can figure, is gluing up the carcass and clamping the veneers on the side with cauls. I've checked with quite a few woodworkers and no one seems to know the best way to achieve this look in a easier way. We'll see what happens.
From contributor Bo
Chad,
I would bet money that there is no way you can get enough clamping pressure from a couple cauls to properly clamp a 5 x 7 piece. Maybe if you have a large screw press but that would cost even more than the vacuum bag. Check www.joewoodworker.com for vacuum supplies and you may find just buying sheet material and making your own bag cheaper. Either way vacuum is still your best bet. As for the edging that is easy and can certainly be done with a couple cauls either before or after the face veneer is applied. Good luck. Another option is to find a shop close to you that does panel pressing and pay them to press it for you, probably cheaper than buying a bag but you only get the one panel and no bag to use again in the future.
Bob
From contributor ch
Thanks. Well I made about 12 5' bowed clamping cauls. I bought a set of the 4' Bowclamps and used those as a template to make larger ones. Put down the veneer glue, paper backed veneer, 2 sheets of 3/4 mdf and cauls every 4 inches. It worked perfect. It kept me really moving and I had everything layed out and ready to roll. Pretty impressed with the caul sytems even pressure.
I had called 2 large veneer companies in mpls. and both said they couldn't do a 5x8 sheet layup. One is a pretty major veneer pressing company, and kind of suprising. So I learned a lot so far on this one. Other major shop kept telling me to just use contact cement. I know that's a big no no. I can't believe how even large shops are clueless on glues etc. and will just try and get away with whatever is easy. I can't afford to do stuff twice.
Thanks for the advice all.
