Can’t get 1 bulkhead to stop leaking

HighChiefKC · May 21, 2020

I have one drain bulkhead out of 3 that has leaked from the start. My first attempt at plumbing the drains, I glued all the pipe (slip x slip). Two of the bulkheads have been perfect since the start. First time leak test the bulkhead leaked from the seal. I tightened it, still leaked. Messed with it for days, still leaked. I finally gave up and assumed there was something wrong with the bulkhead. I took a sawsall and cut the pvc pipe, I had a union below. Replaced half of union and pipe and had to order a new bulkhead. BRS and Premium were sold out of bulkheads. Only size matching I could find was a “stubby” from a plumbing supply store online. Reinstalled new bulkhead and this time I didn’t glue anything. First trial run I can’t find any leak. Put a paper towel around below bulkhead, next morning it’s soaked. I had only hand tightened nut. So I tightened it a quarter turn that morning. Still dripping that night. Last night I take it apart again. Examine the bulkhead, threads, nut, gasket. I don’t see any issues. This time I take the old gasket off and now I have a gasket on the inside and outside. I know that’s not how it’s supposed to be, but I’m trying anything. This morning paper towel is a little less wet and now it looks like it’s leaking from the threads. No water coming from around the hole and gasket like before. I wiped it dry and just kinda pushed on the pipe from above.

Any ideas as to why I’m having a nightmare with this one bulkhead? I inspected the cut hole last night, it seems smooth. I’ve had zero trouble with all the other bulkheads in system.
Any other steps I can take?

najer · May 21, 2020

Maybe a small smear of silicon on the thread where the nut tightens and seats to see if that seals the thread?

X-37B · May 21, 2020

If its leaking at the threads it means its not flush with the bottom of the tank. Is it the very thin gasket on a black pvc standard aquarium bulkhead?
I would replace the gasket with a neoprene type that is standard on scheduled 40/80 pvc. They are thicker and you can tighten them more as they compress.
I always smear some aquarium silicone on the gasket and then lightly tighten it down with the bulkhead in place.
Wait 24 hours to cure. Then tighten it down and your good. This seals the gasket to the tank. I never need this if running schedule 40/80 bulk heads with the thicker gaskets though.

X-37B · May 21, 2020

najer said:
Maybe a small smear of silicon on the thread where the nut tightens and seats to see if that seals the thread?

Silicone on the threads does nothing.
The seal is the gasket.

AlexG · May 21, 2020

Bulkheads can be frustrating sometimes. I would recommend completely removing the bulkhead and clean gasket with alcohol along with the sealing surface on the tank to ensure it is as clean as possible. The bulkhead can be installed again on its own you can lightly apply some silicone and let it cure for 24 hours. I would also ensure that the plumbing attached to the bulkhead is not putting lateral pressure on the bulkhead seal which can cause it to leak.

canadianeh · May 21, 2020

I had this similar issue with my red sea tank that is currently cycling right now. I tighten and re-tape the thread using pink or white tapes, and it still leaked. I used waterproof caulking around the seem of the joint, and it still leaked.

So I finally got a clear aqueon aquarium sealant and applied it on the inner seam inside the pipe joint and also outer seam of the joint. Voila! It worked!

vetteguy53081 · May 21, 2020

Either seal is damaged, or overtightened. A new gasket is the answer and is the gasket inside the tank or outside. It should be inside.
In an urgency, I lowered water when I had this, loosened bulkhead and dried it up good and used aqueon aquarium sealant - NOT silicone and it was dry for remaining two years when I sold tank

X-37B · May 21, 2020

vetteguy53081 said:
Either seal is damaged, or overtightened. A new gasket is the answer and is the gasket inside the tank or outside. It should be inside.
In an urgency, I lowered water when I had this, loosened bulkhead and dried it up good and used aqueon aquarium sealant - NOT silicone and it was dry for remaining two years when I sold tank

Aquarium sealant is 100% silicone, but I get it.
Dont want someone to just grab any type of silicone and have another issue.

ca1ore · May 21, 2020

Couple of things you can do for a stubborn bulkhead. One is to use silicone sealant on both sides of the gasket. That will seal everything up, but, you have to give it a couple of days to cure. Second is to use one of these. They're Sch80 that fit a Sch40 hole but use O-rings rather than a gasket. You don't say what size bulkhead, so they may not have the one you need. Also, make sure the gasket is under the flange not the nut.

Schedule 80 Bulkhead Slip to Slip

Professional Aquarium Bulkhead Style: Slip to Slip Available in: 1/2in, 3/4in, 1in, 1.25in, 1.5in and 2in

www.coralvue.com

HighChiefKC · May 21, 2020

It’s a 1.5” bulkhead. Which everyone seems to be out of stock, including coralvue.
The original bulkhead had a thicker gasket than the one that came with the stubby bulkhead.
Gasket has always been inside overflow, nut
On outside.
Is there any kind of silicone sealant that I can get at hardware store so I don’t have to wait a week for ordering online?

Here’s the current install of the stubby. I’ve since added the thicker gasket to the outside along with the thinner one on the inside just to see if it would work.

HighChiefKC · May 21, 2020

Is there any kind of silicone sealant that I can get at hardware store so I don’t have to wait a week for ordering online?

HighChiefKC · May 23, 2020

Well I went to ace hardware. Bought a big bulky threadxthread bulkhead that was 1.5”. Turns out it’s a lot bigger in diameter than my drain hole. But it came with a big thick gasket. So I took the gasket off that and I’m using it on the stubby bulkhead. Thing that worries me is the gasket is a lot bigger than the hole, but it seemed like the bulkhead fit good on it and I tightened it down. In the first ten min of tank draining, I didn’t have any drips. We’ll see what the paper towel looks like in a few hours...

flyfisher2 · May 23, 2020

Good luck!
I had same issue on my 180 and after several attempts I discovered that the end of pipe in the sump was contacting the side of the sump and the leverage was causing enough pressure to keep the bulkheaad from seating perfectly. That was enough to cause a drip. After I readjusted the distance in the sump the bulkhead sat properly and I tightened it down. No leak.

mfinn · May 23, 2020

When I install new bulkheads I always use a bead of silicone around the base of the bulkhead where it goes through the glass. My idea is to fill any gap (no matter how big or small it is) between the plastic of the bulkhead and the glass.
It's ok if some squesses out.
I finger tighten the bulkhead and give it a 1/4 turn with a wrench, and then don't touch it atll for at least 24 hours. Some will say make it 48 hours.
The silicone closes the gap in the glass where the threads start.
The silicone will not permanently adhere to the plastic, but will fill any gap.

HighChiefKC · May 23, 2020

Ugh. It still leaks.
they have any safe silicone at Lowe’s?

mfinn · May 23, 2020

HighChiefKC said:
Ugh. It still leaks.
they have any safe silicone at Lowe’s?

any petco's or petsmart's or local fish stores in the area?

HighChiefKC · May 23, 2020

mfinn · May 23, 2020

HighChiefKC said:
Yea

They will usually have small tubes of reef safe silicone.
I'm sure there is a reef safe silicone at Lowes, but over the years there has been some much discussion over which is and which isn't, I just gave up trying to keep it straight.
I usually have Momentive RTV 103 or 108 around, or plan ahead and have it.
I've also ordered the All Glass brand from amazon.
Then when I need a small tube, I got check Petco or Petsmart, which are local to me.

flyfisher2 · May 23, 2020

I drained the area where the bulkhead is with airline tubing and got in there and wiped it clean at the same time that I ensured I relieved the pressure where the other end of pipe was pressing against the sump wall. If the bulkhead isn't perfectly flat it may continue to give problems. Keep in mind we are dealing with glass rubber and plastic. Hope you can get it fixed.