Replacing black/gray tank adapters

[92landyacht]

I'm replacing the two gray and black water tank adapters since they started to crack and leak. The remainder (valves and pipes) are still in good working order. I ordered the two tank adapters from Inland RV and they should arrive some time today. I also ordered two Thetford valve rebuild kits since I needed new O-rings that go between the valve body and the adapters. I also figured this would be a good time to rebuild the valves even though they didn't leak. One question though. What type of sealant should I use on the tank outlets where the adapters go in. I've thought of silicone glue/sealant and I also have some Dicor self leveling lap sealant. Any suggestions on what I should use?

[CRH]

The ones on my trailer are just clamped in. No sealant.

[92landyacht]

Looks like AS did use some form of sealant as both of the adapters that I pulled out of the tanks did have some form of gray coating on them. Since the tanks are nylon and not very compressible I'd feel better having some form of sealant there. Just trying to see what others have used.

[Waipio Rim]

I used silicone and it worked. I read in another thread that Airstream originally used Vulkem.

[CRH]

I thought AS used polyethylene tanks and silicone will not stick to poly.

[A W Warn]

Use Vulkem (or similar polyurethane)or Lexel.
If you use silicone, next time the caulk may hav adhesion issues.

[92landyacht]

Ordered the Vulkem 116 today from Amazon Prime. Should arrive by Tuesday.


Once the valve rebuild kits arrive and the Vulkem arrives, I'll be ready for the re-installation of the drain system. I'll try to post picks of the rebuild process but it looks to be pretty straight forward.