1974 Airstream Fresh Tank Fitting Size - Help!

[Aopsahl7]

Finally getting to plumbing. I am using the original 1974 fresh tank but I have switched to a different tank level monitor system. With that said, I have a bunch of the threaded holes for the old tank level sensors that I need to plug.

For the life of me I cannot figure out what size plug I need. It’s close to a half or 3/8 but those don’t fit. Maybe it’s metric?

Let me know if anyone has any info.

[Jim & Susan]

I don't know the size either, but here's something that might work.

While removing the floor in our '73, I inadvertently cut about a 8" gash across the top of the fresh water tank with a circular saw. I took the tank to the local RV dealership and they were able patch it. If you search around the repair forums here you may be able to find the instructions to do it yourself. Basically, you're just heating a raw plastic repair rod and filling in the open/damaged areas. Problem is I can't remember any of the particulars (what type of plastic, what type of heat source, that kind of stuff).

Somebody else may chime in with more info. Good luck.

JIm

[Aopsahl7]

So after 3 box stores as well as a few local hardware stores I have finally made some progress.

The fitting is a 3/8 mip. Where this goes sideways is no one seems to make a 3/8 mip elbow to 1/2 pex. I am going to check McMaster tonight.