Inquiry concerning CPVC pipe for outdoor use
Inquiry concerning CPVC pipe for outdoor use
(OP)
thread378-215896: UV protection for PVC
Gentlemen, I read your thread with great interest. I am involved in boat-building and wish to explore using CPVC schedule 80 pipe to replace stainless steel for some structural components on a boat in a hi-use outdoor marine setting. Many inflatable boats are made of PVC and have PVC fittings all over them for handles, stand-offs, etc... They are mostly useless in 4-5 years due to UV degradation.
I wish to custom bend, possibly weld lengths of sched 80 11/2" pipe into grab rails in sections as long as 4 feet. Out of the box, the application works, as CPVC -80 is strong and stiff, but I am concerned about maintaining strength and integrity over a time span of 5-10 years. Grab rail standards in the marine environment is a serious affair.
Can you suggest durable UV protective coatings that don't scrape off, or other means that I might employ to make the pipe useable??
Gentlemen, I read your thread with great interest. I am involved in boat-building and wish to explore using CPVC schedule 80 pipe to replace stainless steel for some structural components on a boat in a hi-use outdoor marine setting. Many inflatable boats are made of PVC and have PVC fittings all over them for handles, stand-offs, etc... They are mostly useless in 4-5 years due to UV degradation.
I wish to custom bend, possibly weld lengths of sched 80 11/2" pipe into grab rails in sections as long as 4 feet. Out of the box, the application works, as CPVC -80 is strong and stiff, but I am concerned about maintaining strength and integrity over a time span of 5-10 years. Grab rail standards in the marine environment is a serious affair.
Can you suggest durable UV protective coatings that don't scrape off, or other means that I might employ to make the pipe useable??





RE: Inquiry concerning CPVC pipe for outdoor use
Who's your lawyer gonna call?
Yes, I know CPVC is great stuff, but the plastic piping industry has had some, ahem, hiccups, over the years, with class action suits and such about other, initially promising, materials.
You're proposing a new use for a relatively new product, and expecting long term performance in an application for which the product has not been specifically tested. Do not expect a CPVC producer to become a willing codefendant.
For some illumination, go to blazemaster.com, a site owned by Lubrizol that sells CPVC for use in fire sprinklers, and also goes to some trouble to explain that environmental stress cracking is already a known problem.
Search the site (search box in u/r corner) for the word 'incompatible'. The page that you will find lists, among other things, SikaFlex sealant and WD40 as specifically _not_ approved for contact with CPVC. Both are likely to be found on boats.
Environmental stress cracking in plastics doesn't work the same way as it does in metals; the environmental stress and the physical stress can be separated in time and still cause a failure, and the environmental stress exposure may be very brief and still cause failure.
The best/ worst/ easiest example of ESC in plastics is polycarbonate. Make a coupon, bend it, twist it, beat on it, you can't break it. Dip a similar coupon in any of dozens of solvents, wipe it off immediately, wash it if you like, try to bend it, and it snaps like glass. CPVC may not be that dramatic... or it may be.
My suggestion: Stick to stainless steel; you got trouble enough.
Mike Halloran
Pembroke Pines, FL, USA
RE: Inquiry concerning CPVC pipe for outdoor use
RE: Inquiry concerning CPVC pipe for outdoor use
Dinghy
RE: Inquiry concerning CPVC pipe for outdoor use
RE: Inquiry concerning CPVC pipe for outdoor use
I have promoted plastics materials into new applications for most of my life. I would run away from this as fast as I could yelling don't do it don't do it.
Regards
Pat
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