# glue plastic lumber?



## Danpaddles (Jan 26, 2012)

I am thinking to repurpose some salvaged deck boards, the kind they make from milk jugs. I did some looking on suppliers web pages, but most references to gluing are a little vague, if not downright dismal.

I am thinking to run a dado lengthwise on the underside of slats, to use on a garden bench. Then, a narrow strip will be glued and screwed into the dado. I am trying to take out some of the flex of those plastic boards. So the glue will be pretty well protected from weather/ UV rays.

Anyone ever tried gorilla glue with those boards? One manuf. recommended Lexcel, but I can not find out anything about it, not even who makes it. I have a feeling it may be a polyurethane though. West Systems Epoxy talks about it a little, they recommend providing a means for a physical …. grip, or a surface preparation, to let their epoxy grab.

Using PolyU (Gorilla) is more appealing to me then using West systems, partly because I am a cheap SOB, I have almost no West Systems left in the can. And that stuff is not cheap.

Alternatively, I could just make a little bench, maybe only 2 and a half feet wide, then the flex would not be a problem.

Ideas? Thoughts?

thanks guys-


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## ClintSearl (Dec 8, 2011)

PL Polyurethane construction adhesive.


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## Jeff28078 (Aug 27, 2009)

From what I looked up many people suggest Gorilla glue but with some extra support such as you're going to provide with the screws. Even a Trex rep suggested Gorilla. Let us know how it turns out.


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## oluf (Jan 29, 2010)

If you have enough material I would reccomend making the seat double thickness. Space your joints as far apart as possable. Glue the two boards together with construction adheasive and fasten with lots of screws up from the bottem. Got enough boards? make them three thick.


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## Danpaddles (Jan 26, 2012)

Well, Oluf, the curve of the bench would make it tough to just add thickness. I am actually using a 5/4 board, right now the bench has 3/4 wood on it. So I will be increasing the thickness some. But we have set the 5/4 boards on sawhorses, they are just not real strong.

Clint, I'm gonna look real close at the label on that PL Polyurethane construction adhesive. Might be just what I want. Otherwise, I have a bottle of Gorilla glue out there now.

This is a Spring Break project (my 16 y.o. needs to work off some bad karma) so I will know by the end of the week.

thanks a bunch for taking the time to post, this was just the help I was looking for!


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## crank49 (Apr 7, 2010)

If those boards are made from milk bottles, that is polyethelene plastic and there is no glue that will bond to that.

But, the construction adhesives, like PL, will stick to it pretty good, just not a solid bond like PVA on wood.

What kind of strip are you putting in the dado? Can it be proud of the bottom surface?

You are correct that plastic composite deck boards are flexible. They barely function as a walking surface and feel springy even with joists on 12" centers. Best thing I have come up with for repurposing this material is sill material under walls installed in a basement.


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## Danpaddles (Jan 26, 2012)

Michael, I am looking to just add a strip of the same material- sticking proud by an inch or so, to keep it from bending so much. I will be able to pepper it with screws, anyway. Sticky may be good enough. And if the whole thing craps out next year, well, we will have had one year from the bench. We are not talking fancy stuff here, the original came from HP. But the cast iron is still in good shape.

I gotta have SOMETHING to keep this dang teenager busy. He thought he would be sleeping for the whole Spring break.


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## Danpaddles (Jan 26, 2012)

We ended up using PL construction adhesive. With lots of screws, it is good. The whole project turned out great! He worked at it, painted some, cut the boards, drove some screws, and did the final assembly.

thanks!


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## Danpaddles (Jan 26, 2012)

P.S.- there was some PL adhesive drippings on some his scraps. I was picking up today, noticed the drips, gave them a test. They have almost no grab on the poly wood, I could lift the globs off cleanly with my fingers.

Oh well.

hindsight is 20-20- but maybe I should have tried a hot melt glue gun. Some poly is weldable.


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