The hose thingy

[Della and Dave]

We have been having a "heck" of a time
Getting the new sanitation hose back
On the siphon break U back behind the shower stall.  This was necessary because I cut off the old hose when we overhauled the through hulls and figured, just put on a new one, no problem.....

Working behind the lav vanity makes it hard to get much heat on the hose without burning it.  I have tried boiling water, but it's hard to pull that off without pouring it all over yourself, and the thing cools quickly.  If it were 100F here, might be a different problem.  Three major attempts and three failures brought me to make this gadget: 

Two pieces of all thread and a coupling from chain link fencing with slots cut.  I haven't tried it yet, hope to over the weekend, but I figured I would throw it out to stir things up.  I plan to stuff it into the end of the hose, expand it and then heat it up carefully with a heat gun and an IR thermometer. Hopefully I can get it back out..... I am open to other brilliant ideas for haw to get the !*%{^<!\+]=!!! Hose onto the barbed fitting.  (Yes they are the right size...).

[Della and Dave]

If worked!  We now have a functioning head.   Here it us installed in the hose. 
I was worried about over heating the hose, maybe too much.  I read what they said on the shields web site for the hose and they said not to use a heat gun because you could easily overheat it and it wouldn't contain odors, and life as we know it would end.  Then I talked to other people on the docks, and they use a heat gun all the time.  The thingy worked for me because it let me expand the hose, and use a heat gun carefully, and when it cooled, it had stretched so I could get a hand on it to install it.  Everything else I tried it cooled before I could really get it over the fitting.  The string did two things, it kept me from dropping it, but it also told me when the heat gun was hot enough to melt the string.   

[SVJourney]

Nice job Dave,
If anyone else wants to do this without McGuivering a tool, a tailpipe expander would be the ticket.  They are available at any autoparts store that sells tools.

[Della and Dave]

Why didn't I think of that!    It was fun anyway and I had the bits in the shop, so no harm no foul.  Twenty minutes in the shop saved be 15 bucks plus shipping for me.  The auto parts stores might have it, even up here, but there isn't as much fun in that. 

[PeteW]

I've done a lot of wrestling with the Trident (white) sanitation hose. What I can you tell right off is that not all 1 1/2" hose bards are actually 1 1/2".  The grey plastic ones are the worst. Those need to have the OD sanded down. The white ones (nylon I think) will go on given enough compressive force. But this is a force that no human can muster. The only way to get those on is to pre-assemble the sections on the dock. When heated and lubricated these will pop right on when hit with a compressive blow of a sledge hammer. The bronze barb nipples you can actually push on by hand.  

There is always one piece of hose you can't pre-assemble. For that last connection I substitute a piece of 1 1/2" wet exhaust hose which I think is a better product than the trident stuff anyway. Its double wall, wire reinforced, multi ply rubber and it can be pushed onto a hose barb by a human with moderate upper body strength. And don't forget the double clamps.

I've tried stretching the Trident stuff with a tapper bung. It simply ruined the hose because it does not stretch.

Pete

[Della and Dave]

I tried the tapered bung too, that was abject failure number two.  I was using the Shields white hose, but I think it is pretty similar to the Trident stuff.  Practical Sailor did a review of the different hoses that are available for controlling head odors.  I don't think any of the white plastics actually came out that great.  If I remember correctly, it was a black rubber wire wrapped hose that scored best in their tests, but when I went looking for it, out local west marine didn't carry it, and it was really expensive to order ($24 per foot plus shipping).  The Shields was available at the chandlery in Seward, and fixing the head was high on the family satisfaction with the boat index. 

You comment on the size of the fitting is spot on.  I measured the hose ID at 1.488 inches with calipers, but over the bronze barb fittings is was 1.685.  A real challenge to stretch it that much.  I filed on the barbs a lot and got them down to about 1.590, but not really perfectly round as hard as I tried to keep it.  Working with a hand file back behind the shower stall didn't work that well. I did get the nasty casting seam in the bronze filed out though.

I understand that Shields makes fittings that are longer and a little smaller in diameter without barbs, and they are a lot easier to get the hose on, but that would have meant more tearing stuff apart and the hose on the other end of the U would have had to change, and I really didn't want to get into that.  I was really nervous about overheating it because the instructions said not to heat it over boiling water and not to use a heat gun, so I used a heat gun in the end because that is the only thing that worked.  If it starts to cause odors in the future I think I will just cover it with $100 dollar bills laminated in rubber cement.