Urethane or Hypalon for tubes?

[sunrider]

The link below is to a report made in 1993 by the US Navy comparing the benefits of Urethane versus Hypalon coated fabric for use in RIBs. Does anyone know of more current research or information on the subject, or discussion of other types of fabric? In particular, I would like to learn what research has shown to be the best material to use in a high UV location such as Hawaii.

http://www.wing.com/PUvHYPE%204.13.05.pdf

[boatster]

Thinking of retubing some more Willard ribs?

Very interesting read btw, thanks for that. So when they state "urethane coated fabrics" do they mean the pvc material that boats at West Marine and Zodiac sell as tenders? It seems, according to this document the urethane coated fabrics are much better suited for ribs. Or am I getting urethane as in polyurethane mixed up with pvc ?

I wonder how the military determines when a tubeset is worn out. The document says the British Military replace every 8 years. My Avon sr4 is roughly 14 years old. I doubt they replaced the tubes during its life. How would you know it was going bad? They don't leak air and all the seams are still good. Seems good to me.

[boatster]

BTW Sunrider,

Did you see those 2 Willards in HI that are up for auction?

[codprawn]

Having seen Avon's still going strong after 20 yrs of REAL abuse I find it strange anyone could want anything other than Hypalon!!!

[limeydal]

where do you get the links for the HI auction??
Would like to check them out;
cheers Dal

[boatster]

Just promise you won't bid against me if a rib pops up in California

http://cgi.govliquidation.com/auction/view?id=616509

[sunrider]

Yes boatster, I saw the Willards in Hawaii. I bought one on the previous auction there and the current ones are similar, but may not be in as good condition. I'm getting some current prices on tube sets, but don't think I will need one for the Willard I already have..but perhaps one of the others. It may be as easy for me to work on a couple of them as on one while I'm in the islands so will be watching the bids. About the fabric...I'm told that the west marine and zodiac non-hypalon boats are usually made from Strongan, a proprietary coated fabric developed by Zodiac. Others may have more accurate information though. I believe the pvc boats are straight pvc, and the urethane products are coated fabric...but others will know more than I on that subject as well and I hope we hear from them on this forum.

Limeydal, they are being auctioned by the government - there are multiple sites that post boats for auction by the government (at every level) and you can find the entire list easily via Google.

codprawn, I'm with you on being very satisfied with hypalon. that's why this research was so interesting to me - it seems to favor urethane. My experience with Hypalon has been great. My primary RIB has been in the unprotected sun, and all oceans, since 1991. The tubes are oxidized but still hold air well. I've contacted the Navy to see if they have any updates to this research and will post any results I come across.

[boatster]

Sunrider,

The urethane seems to win in the manufacture, weight, and strength dept according to that article. Very compelling argument, but with such a good reputation for hypalon only time or a good weathering test can determine how Urethane materials hold up. I can't imagine that someone hasn't already made a better material with all the technology we have today. Aren't the USCG & military going towards those SAFE boat foam collard boats anyways?

[codprawn]

Better technology today??? NOT always the case - for example most paints these days are not as good as the oldies - becuase of environmental reasons - the same with antifoulings.

Look at guns - modern technology hasn't really come up with a better way of killing people on a man to man basis - the Browning 0.5" machine gun is still in use - first came out in 1921!!!

Then you have jet engines - more fuel efficient and quieter BUT speeds have dropped since the 60s.

So just becuase it is newer doesn't ALWAYS mean better!!!

[prairie tuber]

I did some research into this a year or so ago, and came to the conclusion that while polyurethane may have better abrasion resistance than hypalon, it will deteriorate (as will PVC/strongan - same thing) far more rapidly than hypalon will, especially with UV exposure. Additionally polyurethane & PVC are much more difficult for DIY repairs, usually the tubes need to be repaired by the manufacturers.

Zodiac's pleasure boats went to PVC (strongan) for the main reason of reducing productions costs. Their are some applications, where things can be done with PVC that can't be done with hypalon (such as air floors). As for Zodiac's Professional & Military boats, all but one (the gs 380 with air floor) use hypalon rather than PVC. Again the cost of those hypalon boats is far greater than their PVC counterparts. For example, if you look at Zodiac's military futura commando 470 (probably zodiacs most famous craft), it will easily cost double what the PVC Futura Mark III would cost.

For me, I would only consider hypalon if I am spending several thousands of dollars on a boat.