fresh water hose join to pipe


Duane Siegfri
 

I have to replace a length of fresh water hose between the water heater and the distribution piping on the aft engine room bulkhead.  


I've read that Amel puts glue in the hose-to-pipe joint since there is not a barb involved.  Any recommendation on type of glue?  I'm thinking about using 3M's 5200, or would RTV work?


I couldn't get the hose off without cutting it, but when I cut it down the length of the pipe it peeled right off.  It's questionable whether it was glued on, but I like the belt-and-suspenders approach.


Thanks,

Duane

Wanderer, SM#477


greatketch@...
 

Duane,

I used 3M weatherstripping adhesive, a rubber based contact cement, to set my hoses on the unbarbed Amel fittings.  I am sure lots of different ones would work.  Silicon (RTV) is probably not a really good choice.  I don't think it is "adhesive" enough for this application.  Once installed, I used double clamps, with a healthy dose of silicon grease in the screw to help avoid corrosion.

For removing hoses it is a bad idea to cut them off if it can be at all avoided.  You risk scratching the fitting, and providing a leak path that can be very tough to seal.  Look for a tool the automotive mechanics call a "heater hose puller".  Basically a hook you slide uder the hose that lets you pull and pry it off without damage to the underlying fitting.

Bill Kinney
SM#160 Harmonie
La Paraguera, Puerto Rico


Gary Wells
 

I know there is much more expertise here than mine, but I wanted to share that using an RTV to affix hose-to-pipe didn't work so well on my boat.  This is unrelated to the freshwater, but I can see that it could cause a blockage just the same.  My boat's P.O. (or somebody doing maintenance on it) had attached pretty much all the seawater coolant hoses to the pipes with liberal clear silicon sealant.  A noble thought, but as you clamp it down it creates a ring of sealant that squeezes out of the end of the hose from the compression of the clamps.  OK on the outside, but not so on the inside.  I had to clear a pretty good blockage of silicon pieces and one nearly complete o-ring of it from the heat exchanger.

If you do use a glue or sealant, use it very sparingly to prevent any contamination on the inside of the water lines.I reassembled everything with no sealants or glues and there have been no leaks at all ... well .. there's this water heater thing, but that's a know entity :)

Take care!

Gary W.
SM 209 Adagio
Fethiye, Turkey








Duane Siegfri
 

Gary & Bill,

Thanks for the information!  I wondered how an RTV (or even 5200) would work.  Would you wait until it set to tighten clamps?  If you do you could leave channels in the RTV that the band clamps wouldn't seal.  If you tighten the band clamps first, then most of the RTV would be squeezed out.  I hadn't thought about a contact cement, good idea!

Duane
Wanderer, SM#477


greatketch@...
 

Duane,

Good question, and you have the issues right.  You want to tighten the clamps before the adhesive cures.  

That is one of the reasons that silicone or RTV is not a good choice for this application. This kind of product makes a good gasket, but not such a good thin line glue.  For this application you want a glue, not a gasket.  The "goop" is there to help hold the hose on--not to prevent leaks.  And for this application you do not need a great glue.  The surface area is very large compared to the forces trying to pull the hose off.

As an aside, I have a strong bias against 5200. I don't keep any in my ship's stores.  It is SUCH a good adhesive, that it really (IMO) only belongs on things that are being installed PERMANENTLY.  Think joint between keel and hull. I have pulled the gelcoat off fiberglass removing deck fittings that someone bedded with this stuff. One of the issues is it is a better adhesive than it is a sealant.  Something bedded with 5200 can start to leak, but it is still stuck down with the tenacity of a pitbull with a bone.  Since I know that sooner or later I'll be taking just about about everything off to repair, maintain or rebed, as a rule, I avoid it.

Bill Kinney
SM#160 Harmonie
La Parguera, Puerto Rico



---In amelyachtowners@..., <sailor63109@...> wrote :

Gary & Bill,

Thanks for the information!  I wondered how an RTV (or even 5200) would work.  Would you wait until it set to tighten clamps?  If you do you could leave channels in the RTV that the band clamps wouldn't seal.  If you tighten the band clamps first, then most of the RTV would be squeezed out.  I hadn't thought about a contact cement, good idea!

Duane
Wanderer, SM#477


Duane Siegfri
 

Bill,

One last question on using contact cement to join the unbarbed connections.

Do you spread it on both surfaces and allow it to become tacky before joining as usual?  Usually contact cement bonds on contact so how can you slide the hose onto the pipe?  Do you just spread it on the pipe, slide the hose on while still wet?

Normally I would go get some scrap pipe and try it out, but I'm on foot in the boatyard and Home Depot is a long walk.

Thanks,
Duane
Wanderer, SM#477
Hard aground in the boatyard...


greatketch@...
 


Duane,

Good question...  I actually spread cement on the male connector, and then slide the hose on while the cement is still wet.  double clamping immediately.  It does take some time to dry, and certainly is not "full strength" when done that way but the next day the hose is on tight.  An additional advantage to doing it this way, is the wet cement acts as a lubricant, making it easy to slide the hose on to its full length.  

I put the cement on the male side so that as little as possible ends up inside the hose.  When I put a hose on this way it is not easy to remove, but it is possible--which is what I am looking for.

I have never felt the need to do this with "barbed" fittings but the smooth male connectors Amel uses seem like they need more than just clamps.

Bill Kinney
SM#160, Harmonie
Punta Montalva, Puerto Rico


---In amelyachtowners@..., <sailor63109@...> wrote :

Bill,

One last question on using contact cement to join the unbarbed connections.

Do you spread it on both surfaces and allow it to become tacky before joining as usual?  Usually contact cement bonds on contact so how can you slide the hose onto the pipe?  Do you just spread it on the pipe, slide the hose on while still wet?

Normally I would go get some scrap pipe and try it out, but I'm on foot in the boatyard and Home Depot is a long walk.

Thanks,
Duane
Wanderer, SM#477
Hard aground in the boatyard...