cellular pvc for underwater fixtures

[finefurn]

Has anyone ever used cellular PVC for continuous underwater use. It's the type of PVC used for wood trim in building construction, trade names AZECK, or Kleer. I know it will work fine in the short term. My concern is: Will it turn brittle after a few years, and what effect antifouling paint may have. Specifically I will be making various fixtures for use as mounting blocks for a variety of electronic transducers.

[GordMay]

FWIW:
“... WARNING: AZEK Trim products cannot be used in any stress or structural applications. AZEK Trim products can only be used as the decorative part of your application ...”
➥ https://azek.com/resources/faqs

Why not phone ➥ 1-877-ASK-AZEK

or ➥ https://azek.com/contact

[chris mac]

I've been installing siding for the last couple decades. I've used azek and knock off brands quite a few times. Uv won't hurt it too much, but temp changes will. It has a lot of expansion/contraction due to temp. Enough that adhesion might let go eventually(at the perfectly wrong time of course)
It also isn't too dense, mounting through it will compress it over time.
If you want to use something like this, I would suggest composite decking. Maybe fiberon. Something solid core.
It still expands with temp, but not nearly as much. And it is designed to take abuse, much denser. I've used it to mount my transducer. It has lasted 2 years in alberta so far.