Tank patch

[GeocamperAS]

I have a 1978 polyethylene fresh water tank. The large fill nipple that looks like it was glued or epoxied to the tank seems to be coming apart.
I have searched the threads for what type of glue, caulk, or epoxy to use. The threads I found don't seem to be current.
So what should I use?
Thanks

[markdoane]

If its polyethylene you only real option is to cut it out and weld in a new one. You'll need help from a pro for this one.
If it's on a flat section you can use a bulkhead fitting, but they're hard to keep clean and sanitary.

[Tom Nugler]

Hot air plastic welding can be done by better body shops. Call around and see who may do that type of repair in your area.
I assume the filler isn't under pressure so it should be an easy job to do.
They will be more receptive if you agree to bring them the tank and drop it off for a day or two.

Tom

[Kyle401]

You can use a soldering iron with a flattened tip to plastic weld an HDPE tank with cracks. Strips of milk or juice jugs can be used to add material where necessary. Work from the bottom of the crack up to be sure that you join the full thickness of the material.

There are several youtube videos demonstrating the process. I would recommend that you make sure that you are in a well ventilated space and run a fan to blow the fumes away from you. Most thermoplastics can be repaired in this manner.

[Protagonist]

Originally Posted by Kyle401

You can use a soldering iron with a flattened tip to plastic weld an HDPE tank with cracks. Strips of milk or juice jugs can be used to add material where necessary. Work from the bottom of the crack up to be sure that you join the full thickness of the material.

Excellent suggestion. Both milk and juice jugs are made of food-grade plastics, which is what you need to use when repairing a plastic potable water tank.

[dlb435]

Harbor Freight sells a plastic welding kit that I have used to repair tanks in my old Airstream. It's not very expensive and works very well. You will need to clean off all of the old glue/resin that was used to patch the tank.
You will need an air compessor to supply it with air pressure.