How well does HDPE lumber hold up to marine envronment?

[Mark42]

Thinking of using some HDPE dimensional lumber for some pieces on my boat. (I think the white plastic dimensional trim boards at Lowes are HDPE High Density Polyetheline). It has no wood fibers and is made entirely of recycled plastic like milk bottles and plastic bags.

Wondering if anyone has used this material on their boat and how well it held up.

 

[tashasdaddy]

Re: How well does HDPE lumber hold up to marine envronment?

Mark i have used it as trim, not on a boat, NEVER AGAIN. you can't nail thru it, has to be drilled and then nailed or screwed. the easiest thing i found was to hot glue it.

 

[erikgreen]

Re: How well does HDPE lumber hold up to marine envronment?

Lots of people have thought of doing this, but none have tried and succeeded.

Basically the stuff is very rot resistant since it's non organic, but its other properties make it very difficult to nail, glue, glass, or otherwise fasten.

If you really want non-rotting structural members, spend the money for foam core fiberglass stringers or mold deck sections out of pure non-cored fiberglass.

Don't feel bad about the idea...this is probably the most common thing that I've seen folks repairing boats here suggest after they encounter their first rotting hull.


Erik

 

[Mark42]

Re: How well does HDPE lumber hold up to marine envronment?

The decorative shutters on my shed are made from HDPE. Just a few vertical pieces of 1x3 with two horiztals on each shutter. They were never painted, and other than some mildew, the sun and weather has never bothered them. So I thought it would be good for marine use. But seeing as its not really structural stuff, it shouldn't be used for stringers or transom. But I could see it being used as a slat floor in a tinny or other small boat.

 

[Ned L]

Re: How well does HDPE lumber hold up to marine envronment?

I believe HDPE is not as stiff as wood lumber, which would also make it undesirable for structural uses such as stringers. If you look at the stuff like "Trex" decking, they recommend joists at 12" centers because of just this reason.

 

[tashasdaddy]

Re: How well does HDPE lumber hold up to marine envronment?

trex, is also heavy.

 

[ondarvr]

Re: How well does HDPE lumber hold up to marine envronment?

I haven't seen the HDPE stuff, but I do see the PVC trim boards, they're fairly light compared to recycled boards and could work very well, I use them for trim on my house, you can even glue them with PVC glue.

Don't go with the recycled milk jug type stuff, it's junk, Many of the types of plastics used to make them are not designed to be used outside and the heat resistance is low, they can't be painted, they change shape, plus many of them have wood fiber in them.

 

[180shabah]

Re: How well does HDPE lumber hold up to marine envronment?

Mark, do you have a project in mind, or just thinking out loud?

 

[fdmsiv]

Re: How well does HDPE lumber hold up to marine envronment?

I have thought about this approach also, but have not found what I am looking for.

All of the stuff at HD seems to be PVC, when you cross cut it you don't get an even surface, the core of the material has bubbles in it.

I have never seen or used Starboard, but I imagine it is similar to the stuff I have seen the guys on Router Workshop and New Yankee shows. These types of materials can be machined, drilled, etc. They have a solid, consistent make up throughout the material. I haven't checked today, but the price of Starboard rivals gold or platinum.

Anywho, the HD stuff glues up with pvc cement and can leave a weird looking joint (if you have ever build a plastic model with testors glue and put too much glue on the joint).

 

[ondarvr]

Re: How well does HDPE lumber hold up to marine envronment?

Yes the PVC boards are slightly foamed to make them lighter, easier to work with and less expensive. This can be an issue if you want an exposed cut edge, the good part is there are many shapes and sizes, so you should be able to find what you need. Sloppy gluing can leave an ugly joint, but it doesn't need to be glued, that's just one option, most any caulk can be used with it also.

 

[GO OVRIT]

Re: How well does HDPE lumber hold up to marine envronment?

I use a bunch of the pvc on exteriors of houses. It holds up great, but moves too much for a lot of uses. Example: I ran a 1x8 across the band of a porch mith miter cut ends and uses "trim" screws summer before last. This past spring it had to be removed for acsess behind it. It sat in the cold air all night and was 5/16" shorter (on an 18' run) when I tried to put it back. It had to sit inside with a heater all day. Its also very expensive. The last 3/4" 4x8 sheet was $110.

 

[Maine Tom]

Re: How well does HDPE lumber hold up to marine envronment?

I have used it on many jobs (I am a builder) where it is exposed to salt air with great results. I also have used it for different projects on my boat. Last year we added a leaning post with tackle storage and it works and looks great. I will be changing a few hatch covers as soon as I get some large leftover scraps. It is true that you need to pre-drill and screw and I use phenoseal adhesive caulk on the joints. It is easy to work with .The brand I have used is AZAK and it come in 4x8 sheets or in common lumber sizes. I was going to use starboard but the price seems way to high me considering I have the AZAK Good luck