Anything I can use under an epoxy glue-up so squeezeout wont stick?

[Doug Shepard]

I need to laminate together vertical plywood strips 1" and 1.5" x 24.5" x 74" with epoxy for layers on a workbench top. I've been building up sections of 4-5 plywood layers so far with yellow glue but will have to switch to epoxy to get those sub-sections glued together for the total width. I think even with the longer epoxy open time, I'm pushing my luck also trying to glue this down to underlying horizontal layers at the same time and I'm not sure I've got enough clamps to do all that at once anyway. I need to keep some cauls on it to hold it down flat, but dont want to have the glue-up stick to the work surface while doing the clamp-up for the width lamination. Any idea what I could use to stop the epoxy squeeze from sticking that lamination down to the work surface? Will paste wax work?

[David Giles]

Hardly anything sticks to polyethylene plastic. Milk jugs are one source of PE. Trex fence is half PE, half wood fibers. I couldn't get epoxy to stick well until I roughed up the surface. Hope that helps.

[Robert Waddell]

I use wax paper for this purpose on yellow glue, glue-ups. I would think it would work fine for what your doing with epoxy.
Rob

[Paul Williams]

I used wax paper. The epoxy squeeze out spreads between the wax paper and the surface of the work and needs to be sanded off.

[josh bjork]

When I've done a glue up like that that I don't have clamps for, I've always used screws. Predrill one layer and screw into the other. I'm not sure how you would get decent clamping pressure otherwise. Not that you need a ton but you want the surface flat? Take the screws out when done if you wish but the holes are in the bottom and glue needs some channels to escape anyhow. I doubt epoxy will squeeze out 12" without some serious pressure.

[John Stevens]

I need to laminate together vertical plywood strips 1" and 1.5" x 24.5" x 74" with epoxy for layers on a workbench top. [snip] ...and I'm not sure I've got enough clamps to do all that at once anyway.

Doug, are you sure you need to clamp it if you're using epoxy? Please (anyone) correct me if I'm wrong, but I thought with epoxy the only concern was to make sure the pieces were in contact with each other, and additional pressure isn't needed. Perhaps a bunch of bricks or cinder blocks would do the trick?

Regards,

John

[Doug Shepard]

John
I'll double check the clamping pressure issue. The bricks wouldn't work until I get ready to put all the horizontal layers together though. Here's a pic. What I've got to do first is the layers made up of verticals so I'll pretty much have to use clamps to hold that together.
72575

The waxed paper and sanding off sounds like it would probably be the quickest/cheapest solution.
Thanks guys.

[John Bailey]

I've use waxed paper for years. It won't stick to epoxy. The other thing you can do, if I'm getting the picture correctly, is to use masking tape on the part of the caul that touches the work surface.

Epoxy doesn't need alot of presser. If you're using unthickened epoxy, the fit will have to be tight. If you're using thickened epoxy, your fit doesn't have to be as tight. In fact, some would say you're better of if it isn't. Don't know if that's true, but thickened epoxy is very forgiving.

John

[Alan Turner]

Wax paper is fine. For the cauls, clear, cheap, packing tape works well also.

[josh bjork]

Disregard me, I thought he wanted to glue up the layers horizontally. If you catch the epoxy sorta soft and half set you might be able to just trim it off with a scraper or somesuch.

[John Bailey]

Disregard me, I thought he wanted to glue up
the layers horizontally. If you catch the epoxy sorta soft and half set you might be able to just trim it off with a scraper or somesuch.

This is good advice, if you wait for the epoxy to cure all the way, you'll have a hard time getting it off without sanding into the wood. Epoxy is hard stuff when cured.

John

[Bernhard Lampert]

As everyone suggested: wax paper. But lately I have used cling wrap (i.e. Saran wrap, etc). I can cover specific parts and it doesn't move once put down. The pressure sensitive wrap works best, since only one side sticks to surfaces.
PS Works great for painting/finishing too.

Cheers,
Bernhard

[John Huber]

I've used the plastic sheeting sold as drop cloths for painters. It's available at the home supply stores. It comes in a roll with an adhesive strip on one side. Epoxy (and any other glue) does not stick to it.

[Jim Becker]

Wax paper? Freezer paper?

[Doug Shepard]

Thanks everyone. I've used wax paper for PVA glue-ups and it works good, but thought I might have issues with epoxy sticking to it. Looks like it works just as well for epoxy. Since I dont have a big vacuum press (or even a small one) my plan of attach on this was to get the 2 layers made up of vertical strips glued up independently, then do the horizontal glue-ups. Was planning on gluing the bottom two 1/2" ply layers and the lowest vertical strip layer together, then the uppermost 1/2" ply layer and top vertical strip layer. Before glueing those 2 sections together, I'm going to trim the horizontal ply layers to the verticals ones with a router and flush trim bit. To make sure those 2 vertical layers are the identical size, my current PVA glue-ups of 4-5 ply layers (mixed 1/2" and 3/4") are done at 3" wide. I'll square up and cut the 1" and 1.5" sections out of those on the TS and number everything so both of those layers go together the same way. So far I've got 8 of the 3" intermediate glue-ups done and it looks like I'll end up at 10 pieces to get my finished width, so epoxy glue on 8 mating joints. I was planning on following the West epoxy instructions for Pre-wetting with unthickened, then adding thickener and putting the thicker epoxy on and clamping. Was planning on doing the same for when I'm putting the horizontal layers together.

[Al Lupone]

If you know anybody that has a boat, see if you can get some of the shrinkwrap. I've used gallons of West epoxy & once cured it will just pop off.
Al

[Doug Shepard]

If you know anybody that has a boat, see if you can get some of the shrinkwrap. I've used gallons of West epoxy & once cured it will just pop off.
Al

That's an excellent idea and I may just know where I can get some.
Thanks

[Rich Engelhardt]

Hello,
Could I offer a suggestion FWIW?
If I'm reading the sketch correctly, the bottom layer of verticles sandwiched between two sub layers of ply and a top layer of ply, appears to be a torsion box of sorts.

If I've read all the threads here on torsion boxes correctly, then a "solid" layer of verticles is probably going to hinder both the strength and the flatness of the final table.