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+-- Thread: Structural Contact Adhesive (/showthread.php?tid=7223530)
Structural Contact Adhesive - Willyou - 02-18-2016
Are any of you familiar with any contact adhesive product that is considered "structural" and permanent? Occasionally, I would like to be able to laminate left-over pieces of 1/4" plywood together to make thicker (1/2" or 3/4") for cabinet making or similar uses. It would be nice to be able to do this without clamping. I'm not sure that readily available products intended for home shop use are strong enough or permanent enough. I've looked around a little and found some (such as 3M) that are marketed as "high strength" but it's not clear exactly what that means. Also, I think, that many of these are for use with industrial equipment and available only in large quantities. Any thoughts or experiences?
Re: Structural Contact Adhesive - CLETUS - 02-18-2016
Have you ever tried removing paneling that had been installed using liquid nails?
I'd consider that permanent.
Of course... a few brads to hold it until the glue dries.
Re: Structural Contact Adhesive - Alan S - 02-18-2016
In my experience, the problem with laminating plywood is making sure the thickness is consistent. Ordinary wood glue holds well enough if you can keep the parts in contact with one another.
A thick (viscous) construction adhesive should be plenty strong, but would be more difficult to squeeze together, so would make it more difficult to achieve an even thickness.
While we usually want more clamping pressure to make a glueline less visible, much less pressure is needed for a strong join. Piling weight on a couple of plywood sheets on a good flat surface should do, as long as they are not too warped to be pressed flat. Brads or screws can help.
Re: Structural Contact Adhesive - Willyou - 02-18-2016
What you said. Plus, I've had very mixed results over the years with liquid nails and similar products. My worst was when the glue completely failed after curing where the cured glue was crumbly. Fortunately, it was not a critical situation.
I've used the typical "off-the-shelf" stuff numerous times for laminate counter tops and it works quite well. Logically, it seems that it should do as well with wood to wood contact. Anyone done this successfully? Let's say, for example, a cabinet shelf, a book shelf, or drawer bottom. I'm thinking that the typical stuff might fail under that kind of loading; even if the failure is only a significant amount of creep.
Re: Structural Contact Adhesive - Robert Adams - 02-18-2016
Sounds like a test drawer bottom for someone's shop is in order. I have glued 1/4" together for heavy tool drawers but didn't use contact cement.
Course allot of that cheap ply looks like they used pink contact cement......
Re: Structural Contact Adhesive - mike4244 - 02-18-2016
I use hot hide glue to laminate plywood. You can laminate thicker pieces (over 1/4") and weight it down instead of clamps.The weight or clamps come off as soon as the glue cools. Not strong yet but will stay in place without peeling apart.
Thinner stock like veneers are done by applying the glue,let it cool,apply the veneer and iron it on.I do not use an iron.I use a heat gun and laminate roller instead of ironing.
I do not know the structural strength of hide glue, I do know it works well to laminate plywood.
mike
Re: Structural Contact Adhesive - chips ahoy - 02-18-2016
I have used PL Premium with good success. Also have used it to glue down plywood sub floor, no way will it come up.
Mel
Re: Structural Contact Adhesive - Steve N - 02-18-2016
Alan S said:
In my experience, the problem with laminating plywood is making sure the thickness is consistent. Ordinary wood glue holds well enough if you can keep the parts in contact with one another.
A thick (viscous) construction adhesive should be plenty strong, but would be more difficult to squeeze together, so would make it more difficult to achieve an even thickness.
All this right here will mean YES you can get 2 pieces of plywood to stick together, but for the most part for any "woodworking" is going to look like it was done by the XYZ Brothers, even rough construction won't lay flat.
Mel stated using this over studs, for attaching a subfloor, this is the intended use, and it works because you are screwing it down to the 2x material. Screws are the worlds cheapest clamps.
Re: Structural Contact Adhesive - Cooler - 02-19-2016
I've glued up plywood sheets. No clamps. Just some weight to keep it in contact. Fast and easy.
Re: Structural Contact Adhesive - Willyou - 02-19-2016
Cooler,
I agree. Done it myself a number of times. But I'm wondering if contact adhesive can be a good alternative, especially for larger pieces that are more difficult to clamp and/or lie flat and weight.