Trex and Glue?

[semenza]

    I am doing  non-construction, non-deck project. I would like to glue (and screw) two layers of  Trex (has the shape I want), or other composite, deck boards together into a double thick piece.  The glue would be more to keep them tightly sealed rather than for any real strength. Is there a type of glue that will do this? This will be for a spacer rather than any load  bearing or strength situation.

  Also would there be much lateral movement across a 3" wide piece (about a half a deck board width)?

Seth

 

[waho6o9]

From

Trex.com:

CAN TREX DECK BOARDS BE GLUED? TOP
Glue cannot be used as a primary fastener. When using Trex Fascia, glue can be used as a secondary fastener – see Fascia instructions in the Installation Guide for more details.

I'd use JBweld clear and run a test piece.

HTH
[big grin]

 

[Brice Burrell]

    I am doing  non-construction, non-deck project. I would like to glue (and screw) two layers of  Trex (has the shape I want), or other composite, deck boards together into a double thick piece.  The glue would be more to keep them tightly sealed rather than for any real strength. Is there a type of glue that will do this? This will be for a spacer rather than any load  bearing or strength situation.

   Also would there be much lateral movement across a 3" wide piece (about a half a deck board width)?

Seth

You mentioned shape, I assume regular PVC trim boards aren't what you're after.  The advantage of PVC is you know it will glue up fine, even if you have to mill the shape you need.

 

[jacko9]

Seth,

Out here in California I know more contractors ripping out Trex than installing it.  The California sun beats that stuff to death very quickly.

Jack

 

[bkharman]

He did say non-decking and non-construction so I assume it is some sort of decretive thing. That being the case, you could try an apoxy and see if you have holding power. Maybe even some gel type cat glue.

 

[blk65brd]

Seth,
Have had good success with Trex 2 x 6 boards that were planed flat and then glued together with Gorilla original glue.  This was all cut down to 3 x 3  and then ran through molding planer for hand rails on an exterior stairway, after 10 years they are still in good shape, we have Trex walkways that are now 20 plus years old.  The house is in Oregon and all of it is exposed to the weather.
Richard

 

[semenza]

    PVC would be fine too, but color is another issue. Really don't want white. Black or gray would be best.  As far as shape goes ............  the regular bull nose is what I meant. Which I could add to anything, but it can't have  it can't have any grooves , etc. on the back side.

  Not supposed to be any mystery here as to the project. I need/want to add two inches (about)  to the height  of  my truck box.  Allowing a bit more room under the tonneau cover. I was thinking a couple layers of composite would work well for weather resistance appearance , and ease of installing.

  Seth

 

[tjbnwi]

Join the two pieces with sex bolts. If you want to seal the seam, use Sikens polyurethane sealant.

Tom

 

[semenza]

Join the two pieces with sex bolts. If you want to seal the seam, use Sikens polyurethane sealant.

Tom

  Yeah, those bolts look like a good idea. As far as sealing goes , I mean between the two layers. Will the Sikens do that?  Just concerned (maybe I don't need to be) about separation in the areas between the bolts. But maybe I don't need to worry about that if I just space the bolts close together?

  I really have not used composite much at all so I am not real familiar with its movement properties. I am thinking that it doesn't move as much as wood?

Seth

 

[jimbouk]

You could use sika flex. That would bond and seal in one.

 

[tjbnwi]

Join the two pieces with sex bolts. If you want to seal the seam, use Sikens polyurethane sealant.

Tom

   Yeah, those bolts look like a good idea. As far as sealing goes , I mean between the two layers. Will the Sikens do that?  Just concerned (maybe I don't need to be) about separation in the areas between the bolts. But maybe I don't need to worry about that if I just space the bolts close together?

   I really have not used composite much at all so I am not real familiar with its movement properties. I am thinking that it doesn't move as much as wood?

Seth

Yes it will.

HomeDepot near you should have it;

http://www.homedepot.com/p/Sikaflex-SL-10-1-fl-oz-Self-Leveling-Sealant-91065/202527281

Tom

 

[roblg3]

my experience has been that any plastics are very responsive to temperature lots of expansion in  heat and contraction in cold temps.  i've had azek trim boards open a butt gap of an 1/8 of an inch in winter after installing in hot summer.(hence the need for bonding the pvc butts together) in your case, i'm not too sure if they would also thicken and thin some, is that even an issue for you? 
if you pvc glue them, they will have to cut apart, think plumbing joints: once set properly i've never seen one come apart

 

[semenza]

my experience has been that any plastics are very responsive to temperature lots of expansion in  heat and contraction in cold temps.  i've had azek trim boards open a butt gap of an 1/8 of an inch in winter after installing in hot summer.(hence the need for bonding the pvc butts together) in your case, i'm not too sure if they would also thicken and thin some, is that even an issue for you? 
if you pvc glue them, they will have to cut apart, think plumbing joints: once set properly i've never seen one come apart

OK, that's good to know. One reason I was thinking the trex  was to avoid expansion and contraction. That could be a real problem. Looks like I will be going a different way.

Seth

 

[rst]

Trex will definitely swell.  I have a Trex deck that I installed with the hidden Eb-Tys when they first came out.  Worked great except that the Trex swelled to the point that the gaps closed preventing drainage.  I have had to go back and use my cordless reciprocating saw to open the joints; MAJOR PAIN! 

 

[semenza]

I could make what I need from wood, but the expansion / contraction is also the concern there.  Maybe a trip to a fabricating shop in my future?

Seth

 

[Kevin D.]

For gluing outside woods and plastics, West Systems G Flex epoxy is great.  Has almost the same strength as their reg epoxy but 32 times the stretcheability.  Really holds up well with expansion and contraction situations.  Has a very honey consistency also.  In some respects is a PITA but in others it makes life a lot easier.

http://www.westsystem.com/ss/g-flex-epoxy/

But insofar of using Trex for your application, Trex is notorious for mold problems.  You may accomplish one task but inherit another problem with mold for your application which to be honest I don't fully understand what it is you are doing as I've never owned a pick up truck and don't even know what the tonneau is.  [unsure]

I know one issue with either Trex, Azek or any of the man made decking is compressive strength.  I had some left over Azek that I was contemplating using for spacers for a deck ledger board to set it away from the wall of the house.  I called Azek and asked whether there is any reason I should not do that.  I was told by their technical person not to as there is no compressive strength for such an application for Azek under constant pressure and not to do such.  Further, I investigated using UV rated Phenolic plastic, and was told that even that would break down over time.  Ended up going with Deck2Wall spacers which are made out of fiberglass.  http://www.deck2wallspacer.com/

And yes, the expansion contraction of Trex but not so much trex is more than that of wood itself.  There products warn plenty in their install guides about what spacings on butt ends and between boards to use for what temperatures you are installing it in.

 

[semenza]

  A tonneau (cover) is a flat or slightly domed cover over the pick-up box that either folds or rolls up to open.  I would like to add a couple inches to the height of my box to allow for a little bit taller space under the cover. 

Seth

 

[Kevin D.]

  A tonneau (cover) is a flat or slightly domed cover over the pick-up box that either folds or rolls up to open.  I would like to add a couple inches to the height of my box to allow for a little bit taller space under the cover. 

Seth

I get it now.  No real suggestions come to mind though....sorry!

 

[bkharman]

Seth. Any reason you don't want to use rubber?  It would be water tight and shouldn't expand/contract. The color should match what you need as well.

 

[semenza]

Seth. Any reason you don't want to use rubber?  It would be water tight and shouldn't expand/contract. The color should match what you need as well.

  I am looking to add two inches. Can I get rubber that thick?  Maybe cut pieces from rubber mats ?  I don't think I could attach the cover to that though.

Seth