Downside To Deforming Head Hose?

[Delancey]

Thanks for sharing your personal first-hand experience. I would be interested to know if others share it as well.

While the risk involved with expanding is obvious, the danger of using ANY heat might not seem so. Given the difficulty in working with this material it would seem to be fairly common practice to use heat to ease in fitting the right size hose to the right size bar. I can think of innumerous times I have seen the hot water method recommended on this forum.

[Hudson Force]

Originally Posted by Terra Nova

............... Most anyone with any boat building experience at all knows how difficult it can sometimes be to install 1-1/2" white sanitation hose on a properly sized 1-1/2" fitting. ............

It is true that my use of heating the hose with a hair drier is normally with effort, in a small and awkward space, to fit a 1-1/2" hose onto a 1-1/2" fitting. I did recently fit a 5/8" garden hose onto a 3/4" barb with the use of heat; however, this was for a shore source of water to a ball valve on the deck for an air conditioning "back flush" to blow water off the intake strainer.
Heat can suit well, but the location and application need to be considered for function and safety.

[Delancey]

Well I called the nice folks at Trident Marine, the manufacturer of the Shield's hose, and spoke to a very nice man who patiently answered my questions.

He confirmed that in fact the VAC XHD hose is comprised of a blend of rigid and flexible PVC that softens around 180F. He couldn't speak as to the softener. If I had to guess it would be phthalates, but who knows.

He seemed to me a little surprised when I questioned whether or not could could damage the hose by limited heating and commented something to the effect of "Sure, you can heat it up and re-form it, no problem. After all, it's plastic!" which is nice because anybody who ever heated up their coextruded PVC head hose with hot water or a hair dryer doesn't have to run out and change all their plumbing in a panic.

He did also seem very surprised when I said I had some success working it with the expander-tool but dispute that it was possible. The hose itself is designed to resist this after all.

I played around with it a little bit today and found that it readily will expand .15" in diameter, but that to go further is difficult without hard spots occurring which result in uneven stretching.

I figure for what it's worth I'll give it a go. I didn't have a caliper the last time I was on the boat, so will have to see what the exact diameter of the flange is. If it is around 1.70" I think it will probably work but is it's closer to 1.75" I am not so sure.

If it doesn't play then I am okay with that, at least I have something to show for my efforts and maybe you do too.

Thanks Trident Marine!

Cheers