Laminating two pieces of ply together

[George Bokros]

I may have the need to laminate two pieces of 1/2" ply together for a project I am working on. I am not sure the best way to proceed. I know I can get 1" ply from Allegheny Plywood in Cleveland but I would only need 1/3 of the sheet and have no use for the remainder of the sheet so I really do not want to do that. That is why I am considering laminating two sheets of 1/2".

My questions are.......

What adhesive to use? Could use contact cement I suppose but because of the size 16" x 95 1/2" it would be difficult for one person to do at least for me. Wood glue but I would have to make sure I got a good even coat over the two pieces. Construction Adhesive would work. How would you recommend / do it?

I would need to place weight on the top to ensure an even bond, how much weight? I could use three or for 50# bags of water softener salt. Also would need to have on a smooth surface to ensure no sagging of the bottom sheet.

How long to leave it weighted down...3 or 4 hours enough?

Thanks for your thoughts and ideas.

[Todd Burch]

I've laminated plywood before. I needed a plywood panel, about 1/2" thick, 14' long and 6' high. I didn't spend too much brain power on it. I cut 1/4" sheets of plywood to make 2 layers that would be 6' x 14' long, and offset all the joints and seams. I then poured massive amounts of yellow glue on one later, spread it quickly with wide putty knives, and then used 3/8" staples to clamp them. Ba-bing, bada-bing. Done. Glue was set in a couple hours.

If you don't trust yourself getting the edges perfect, make it oversized and cut to final size when done.

Todd

[Steve Jenkins]

Don't use construction adhesive. You won't be able to compress it enough. Like Todd said, regular wood glue. I'd swing by one of the big box stores and buy an adhesive roller. Really easy to get a nice even coat. You definately don't want any puddling of the glue.

[George Bokros]

[QUOTE=Steve Jenkins;2485653 buy an adhesive roller. Really easy to get a nice even coat. You definately don't want any puddling of the glue.[/QUOTE]

Is this just a special roller cover for a regular paint roller for applying adhesive? I see them on the HD website.

[Rich Engelhardt]

Those little 3" trim rollers work great.
Last time I glued a couple pieces of ply together, I laid them on the floor of the garage, jacked the car up and slid them under a wheel, then let the jack down.
I put some weights around the perimeter and left it overnight.

[johnny means]

I've laminated plywood hundreds of times for all sorts of uses. Beams, thick panels, giant blocks and any other form you can dream up. You need not get to crazy with your glue application. A simple scribble of glue will do, with a border line around your edges. Really, it's never going to come apart and the sheets are to thick for bubbles and wrinkles to be an issue.

[Steve Jenkins]

Is this just a special roller cover for a regular paint roller for applying adhesive? I see them on the HD website.

Yes it's a special napped cover. It looks sort of like Velcro. It is washable and reusable. I buy the 9" ones and for smaller projects cut the down to fit a 3" roller frame.

[George Bokros]

Steve will this work?

http://www.lowes.com/pd_105732-1748-...dhesive+roller

Thanks

[Robert Engel]

I would use contact cement rolled on with that roller you looking at.

Use sticks about every foot pull from middle and go toward ends.

You should use two coats the first will be a seal coat.

Put two pieces side by side and just flip over on top.

Roll out very thoroughly. No clamps needed.

[Gerry Grzadzinski]

If appearance on one side isn't important, I agree with Todd, Titebond and staples. Quick and easy.

One problem with contact cement is that it can be difficult to apply enouigh pressure to get a good bond, especially if the plywood isn't perfectly flat, which is often the case with plywood.

[George Bokros]

I plan to use Titebond III and put the ply on a know smooth flat surface (a laminate floor) and put 50# bags of water softener salt on the top sheet to apply pressure. Cannot use any fasteners of any kind as both sides are visible.

Thanks for all the input.

[Pat Barry]

Titebond suggests clamping force of 100 PSI for softwoods. I don't think its possible to put enough bags of salt down to get that much pressure. I think you should consider making some clamping cauls or cutting the pieces oversize and screwing them together around the periphery in concert with your sand bags. Then you can cut them to size after they are complete if you don't want the screws

[George Bokros]

cutting the pieces oversize and screwing them together around the periphery in concert with your sand bags. Then you can cut them to size after they are complete if you don't want the screws

How does this apply pressure to the center of the pieces?

[glenn bradley]

How does this apply pressure to the center of the pieces?

I used PVA (Titebond) and a small silicone pasta roller that I got at Wal Mart. If you can't drive screws in for temporary clamps dues to appearance's sake. I weight things down on a flat surface.

Pasta-Roller.jpg . TNNW (12).jpg . TNNW (8).jpg

[Art Mann]

I have only laminated plywood once and that was 1/4 to 3/4 about 18 inches square but I have laminated very large pieces of 3/4 MDF many many times when building up very flat and strong work tables and router tables. I have always gotten excellent results. This is kind of tool I used to spread regular yellow wood glue and it is fast and uniform.

http://www.homedepot.com/p/QEP-1-4-i...0116/203296702

Putting 150 pounds of weight on a large surface isn't even enough to guarantee 100% contact, much less high strength. The manufacturer of Titebond recommends something like 150 pounds per square inch. If you can, use drywall crews that won't penetrate all the way through both layers. Install them on about a 12 inch grid and place the whole assembly on a very flat surface and weight that down to prevent bowing. When the glue dries, remove the drywall screws and you will have a piece that is as strong and uniform as if it were made in a factory.