Has anyone used Recycled Plastic Wood?

[EightyTwo]

I'm looking to build a new picnic table that converts into a garden bench. My old table has pretty much rotted away so I was thinking of using recycled plastic "wood" rather than pressure treated softwood. I know that it's a lot more expensive but with a life of 40+ years, it should see me out!

My main question is about joining the stuff. I know that I can screw/bolt it together but can I make halflap joints? I need to join some sections with minimum thickness so a simple overlap bolted joint wouldn't be suitable.

I assume that mortice and tenon joints (for bracers) are out of the question and that coach screws (or similar) into "end grain" will work much better than they would in wood.

Any experiences of this material?

 

[big-all]

well its plastic so acts like plastic not wood so you cannot use it in the same way as wood
thats assuming its make from recycled plastic and not heat treated wood

 

[nickjb]

In some ways it does act like wood, in others not so much. It routes and cuts like wood. Thinning it depends on the specific material, some is quite foamy inside and will be weakened substantially with a lap joint but some is quite solid. It can also warp a bit after a while. It's all solvable with careful design. I've used it a few times and like it. You should be able to get samples.

 

[foxhole]

You would need to design according to the material so avoiding any half joints etc.

 

[EightyTwo]

Thanks for all your comments - I think I need to talk to the supplier. Half lap joints would allow the 'back' of the bench to be wider so that the 'front' legs would be closer and the bench would look nicer. I guess that butt joints with dowels and pocket screws might be an option.

If your not sure what I'm talking about, search You Tube for: Wood Picnic Table and Bench

Maybe I'll be using timber...

 

[big-all]

dowels wont work
wood glues penetrates the surface gluing the fibers together thats why joints seldom fail on the glue line
where as plastic will not absorb the glue
you must not think wood you must think plastic and alter your construction methods accordingly

 

[EightyTwo]

I understand completely!

I was thinking of unglued dowels just to hold the joint in place while fixing with screws. If I tried screwing through a mitred butt joint parallel to the material (to make a corner, like a picture frame) for example, there is a good chance that the mitred surfaces would slip. I was thinking of using a roll pin or something simiar. This would take the shear forces whilst the screws would work in tension. Pocket screws come in at an angle and, without clamping very securely, could also slip. I appreciate that there isn't a glue that I could use and I don't want to try plastic welding!

 

[foxhole]

Not sure you do has, to be designed with no joints, everything has to be bolted thru.

 

[EightyTwo]

That's the answer I was looking for. Thanks foxhole