Bulkhead leak - Need a fix!

blecki · Dec 13, 2023

Leaking through the union or through the glued joints on either side? Again with the bulkhead - leaking through the threaded part or between the bulkhead and glass?

Bruttal is spot on for glued joints. They are really idiot proof if done right: Lots of glue and a twist to make them leak free. They can't really be re-glued if they leak but if it's a drain pipe (not under pressure) just slather some more glue around the join to plug up any small holes. Or if it's slow enough wait for the salt creep to do it.

For threaded joints, I don't see any thread tape on that one you screwed into the bulkhead. Definitely needs that. Personally I hate threaded bulkheads and avoid them if I can. PITA to get the pipe tight in the bottom without compromising the seal at the top.

jason2459 · Dec 13, 2023

Subsea said:
For reliability, leave valves off drain lines. Even $200 valves will introduce a failure point.

As a senior subsea engineer in deep water drilling on underwater blowout preventer control systems, I mentored corporate design engineers to use the
“kiss“ principle: Keep It Simple, Stupid.

Bean Animal overflow with valve on primary drain works wonderfully.

dadnjesse · Dec 13, 2023

You should use a good plumbers thread sealant on the threaded connections. I like Loctite 567 tread sealant but it's very expensive.

enlighten · Dec 13, 2023

blecki said:
Leaking through the union or through the glued joints on either side? Again with the bulkhead - leaking through the threaded part or between the bulkhead and glass?

Bruttal is spot on for glued joints. They are really idiot proof if done right: Lots of glue and a twist to make them leak free. They can't really be re-glued if they leak but if it's a drain pipe (not under pressure) just slather some more glue around the join to plug up any small holes. Or if it's slow enough wait for the salt creep to do it.

For threaded joints, I don't see any thread tape on that one you screwed into the bulkhead. Definitely needs that. Personally I hate threaded bulkheads and avoid them if I can. PITA to get the pipe tight in the bottom without compromising the seal at the top.

Yeah I feel that, they did have some put maybe not enough. I didnt skimp on the pvc glue connections, those are al solid. With a twist! I went light on the tape and saw leaks on those joints, so I will go heavy on those. When I was loosening the leaky union on the right drain, it was so close to the wood it loosened the bulkhead and leaking between at the glass.

enlighten · Dec 13, 2023

I wanted threaded for easy removal and access in case of replacement. Both are setup as a Durso, so not sure if a spears gate valve would have effect!

enlighten · Dec 13, 2023

dadnjesse said:
You should use a good plumbers thread sealant on the threaded connections. I like Loctite 567 tread sealant but it's very expensive.

I think it would be worth the extra price, the theads at the bulkhead seem to be a problem point, not sure why i am having issues with unions sealing. maybe just not tight or too tight? I usually just do hand tight.

blecki · Dec 13, 2023

Sure the little rubber gasket didn't fall out? It's possible that the union itself is just bad. Damage to the mating surfaces or the rubber could make it leak.

The advantage of slip bulkheads are simple - you won't turn the bulkhead accidentally while screwing in the pipe fitting, and your glue joint is far less likely to leak. Yes you give up the ability to remove them without cutting pipe but it's not like you can't get new ones.

Also sometimes the bulkheads are just crap and the threads don't fit right.

EeyoreIsMySpiritAnimal · Dec 13, 2023

blecki said:
For threaded joints, I don't see any thread tape on that one you screwed into the bulkhead. Definitely needs that

No!

enlighten said:
! I went light on the tape and saw leaks on those joints,

No, no, no. This is not the appropriate application for tape. Use pipe dope or similar (loctite 567, RectorSeal t+2, etc)

enlighten · Dec 13, 2023

EeyoreIsMySpiritAnimal said:
No!

No, no, no. This is not the appropriate application for tape. Use pipe dope or similar (loctite 567, RectorSeal t+2, etc)

I can use rectorseal t plus 2, so to be clear, it is used in leiu of teflon tape or with it?

blecki · Dec 13, 2023

In leiu. They serve the same purpose, don't mix them.

enlighten · Dec 13, 2023

blecki said:
In leiu. They serve the same purpose, don't mix them.

Glad I asked, will do this for sure!

fishyjoes · Dec 13, 2023

One thing I didn't see anybody mention is that when gluing pvc, in addition to inserting with a twist you have to force it together and hold it under pressure for like 10 seconds to prevent "push out" (the pieces can/will separate and make a very weak connection)

enlighten · Dec 13, 2023

fishyjoes said:
One thing I didn't see anybody mention is that when gluing pvc, in addition to inserting with a twist you have to force it together and hold it under pressure for like 10 seconds to prevent "push out" (the pieces can/will separate and make a very weak connection)

Did all this, my glued areas are not presenting any issues atm. It was the threaded area and one of my unions

enlighten · Dec 13, 2023

Do I need to twist the threaded part of the pvc all the way into the bulkhead thread? It does it for the 3/4 but the 1.5" was a little tight and got only halfway up.

blecki · Dec 13, 2023

I've never been able to get them all the way in without silicon grease and a couple strap wrenches... but I guess since you've already glued the other side putting the fitting in away from the tank then dropping it through the hole is out of the question huh?