Composite 2X4's ?

My plywood on frame boat plans call for standard 2"X4" lumber for the frames. Could those be replaced by composite (plastic) 2"X4" instead? Would there be any advantage other than not having to worry about rot, ever? How well would epoxy work using the glue and screw method with this material? I know that composite lumber is more expensive but am curious as to how well that would work.

 

There are two types of these composite boards, neither is well suited as boat framing, though they don't rot, they also don't hold fasteners worth a damn, don't glue well, they bend easily and cost 3 - 4 times as much as a regular 2x4.

 

Besides being very heavy, having no strength, being high in cost, difficult to bond to, and stating on the label "not designed for structural applications"

I imagine it would be great. (Sarcasm)

 

"not designed for structural applications"

What are they intended for ?

 

Non load bearing applications, like hand rails, decking, fences, posts, etc, they come in various dimensions.

There are similar extruded FRP products. In that size they're hollow and not well suited for the job.

 

When I see 70 or 80 year old timber houses being demolished by excavators and sent to landfill, without any attempt at recovery of useable timber, much of which is of a quality unobtainable today, I could almost cry. What a waste of 15 or 20 tons of timber.

 

Go to the landfill when they are hauling it off, you can drive behind them.

Public landfills will usually allow people to salvage trash, lots of pickers at ours. Load it up, it's that much more they don't have to deal with. You may have a minimal charge and by the ton cost.

There's tons of true dimensional oak out there, you might even be pulling square nails out of it!

 

Composite boards also a tremendous amount of expansion due to temperature changes and say on an 8 foot piece, when install decking, you fix the center say with a screw, and then you need to slot the other screws towards the ends so the board can slip under the screw head (pan head) or alternatively for decks require a slip clip that mounts to the
bottom profile flange to allow the board to expand or contract.

 

Thanks guys! I'm trying to learn all I can before I start my project! :idea: