Goop on tank connections

[CA_Tallguy]

Hey folks,


Just wondering if someone can tell me what the recommended goop is on the pipe connections to the waste tanks. I have a 77 excella 500 and it looks to me that one tank may have "pipe dope" whatever that is (speculating that this is what it is but I don't really know) and another tank has perhaps vulkem/trempro.

I e searched the forums but don't see a ready answer and I'm about to disassemble my stuff.

Thanks!

[Jammer]

For threaded connections, there should be a high quality pipe dope, e.g. Rectorseal #5.

Slip connections should be solvent welded.

[CA_Tallguy]

Thanks - but one question... I thought it was a bad idea to solvent weld the valves to the tank otherwise you can't repair them easily in the future?

Here is the setup on one of my valves now and I believe this is fairly common? I seem to have read about similar setups with the pipe clamps on tank outlets...

[Jammer]

There are many ways to do it. On my Cayo, I solvent welded the flanges to the tanks. It is rare for a flange to fail, and if it does there are various alternatives involving cutting out some or all of the old flange. On the other hand, that doesn't work with polyethylene tanks, only with ABS tanks.

I don't see any sealant in your photo, except for some accumulated debris on the valve.

[CA_Tallguy]

Ahhh that makes sense. I think mine may be poly as they are white-ish.

I think the stuff on both was definitely vulkem or something pretty darn rubbery. They were tough to get off.., almost like a rubber band pulling them right back in as I tried to pull out.

I think that I need to investigate pipe dope or something else that won't be so difficult for someone next time. Or maybe vulkem would be ok with your logic about flanges not failing. Hmmm. I'm open to suggestions!

[CA_Tallguy]

The guy at the hardware store suggested butyl caulk. Any thoughts?