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greycode's avatar
greycode
Explorer
Sep 11, 2017

Fresh water tank spin weld fitting cracked - now what?

I have a 10 year old travel trailer that I'm getting ready to sell. I've since purchased a new trailer. While cleaning up and inspecting it, I discovered that the 1/2" spin weld fitting on the fresh water tank that goes to the water pump was cracked. After fussing with it a little, it has since completely cracked into 2 pieces horizontally.

Naively, I attempted to glue it back together. Now I'm beginning to understand that it's probably made of polyethylene and will not bond to glue very easily.

Does anyone have any recommendations? The section that has cracked and fallen off contains around 2/3 of the threads for a male right angle barb connector.

I'm considering the following options:
* melt the two sides and attempt to weld them back together
* use some type of specialty epoxy
* re-tap the fitting and use the lower half

I really don't want to put too much money into this trailer since I'd like to sell it to help pay for my new trailer.

Ideas anyone?
  • Thanks everyone for the great advice.

    I'm going to try one more time with the glue fix. I see that Loctite has a 2 part plastics bonding system that purports to bond well with polyethylene. I feel like the connection would be strong enough if the glue actually bonded the fitting together.

    If this fails, I think I'll just bite the bullet and take it to my dealer for a fix. Hopefully they have a way to patch and spin weld a new $1 fitting on.

    I like the idea of a mechanical fix. However, I fear that punching more holes in the tank will just put me too far down the path of no return...
  • I think plastic weld is the only method for a proper and permanent repair of a poly tank.

    Look at cutting away the old fitting and installing a spin weld patch or fitting in it's place. Not sure if this is a DIY process or not. Requires a special driver for a router. Router spins the patch piece at high speed creating heat that welds the patch in place. Patch pieces/fittings are cheap but the needed tools aren't. Perhaps there's a local shop that can do it?

    Maybe the best thing to do would be call one of the RV holding tank manufacturers like Icon Direct, Plastic-Mart or Tank Depot. They also have spin weld patches and fittings.

    I have to wonder if you could do your own mechanical patch. May use a 1-1/2" or 2" brass flange so you can get a finger(s) inside to install a s/s washer and nut. Drill some additional holes around it. Cut away the old fitting and use a gasket between flange and tank. Water pressure would push tank wall against flange & gasket that would help seal it. If you it mess it up somehow tho., you could be looking at a new tank. Use a reducer bushing to get back down to 1/2".

  • Bite the bullet and have a tech come out. Plastic weld over the old one and have a new one installed.
    I am sure, you would not want to buy a camper, with a jury-rig repair.
  • Virtually none of the epoxies are potable water safe. At least I have not found one yet and I have been looking.

    Your beat bet is to find a local plastic fabricator if you can't do a cold fix.

    Matt
  • 3M makes all sorts of 2 part epoxies. I fixed my grey tank drain pipe with 3M panel bond adhesive used for automotive repairs. It has held well for years now.
  • Bumpyroad wrote:
    can you find tubing that will slip over pipes and use radiator clamps?
    bumpy


    Possibly. The fitting is not completely circular on the outside so I'd need to form it first. It would also be difficult since 1/2 of the fitting is broken off.

    Not sure if this will show up but here's an image of what a new one looks like:

  • TurnThePage wrote:
    Not sure if this would be applicable for you or not. I sealed my fresh water tank output connection, then routed a new hose from the fresh water drain to the water pump. I just used an elbow, Tee, cutoff valve (for draining), some hose and clamps.


    I believe this could work for me as well. I'd need to do some investigation as to where a couple of drains that I have are routed to. My main drain is right next to the fitting and connected with a gate valve. Along the same vein, I might be able to seal/patch this fitting and install a new one next to it.?
  • can you find tubing that will slip over pipes and use radiator clamps?
    bumpy
  • Not sure if this would be applicable for you or not. I sealed my fresh water tank output connection, then routed a new hose from the fresh water drain to the water pump. I just used an elbow, Tee, cutoff valve (for draining), some hose and clamps.

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