Installing Bulkhead Tips

[AZDesertRat]

As I mention many times in this thread, I do not and will not use slip bulkheads. I have seen far too many of them cut apart and thrown away.

As redfish mentioned though, if the slip is on the inside you should not glue the standpipe or fitting in as it will need occasional disassembly and cleaning. If it is external, and slip is what you have and your only choice, not mine though, then do glue a union somewhere close. If you ever have to remove it it will still require cutting apart but you can disassemble it.
I would find thread by thread bulkheads if it were my tank so you can unscrew any fittings in the future and not have to waste a bulkhead.

Silicone does not permanently adhere to plastic or glass and the seal can be easily broken. I would remove it and take the time to investigate why it was dripping and do a proper fix. It's usually some excess plastic in the threads or the flat flange surface that needs filing or sanding smooth.

 

[metrokat]

Thanks AZ

 

[mrvn]

How tight do the bulkheads need to be? I'm setting up a reef ready 60 gallon tank and I'm not sure if I need to use a wrench or only do it by hand

 

[tom reilly]

I have a bulkhead ? for the resident expert....:bigsmile:

I have a custom four sided overflow box I am putting on the inside of the tank. The flange will be on the inside and the bulkhead will go through the back wall of the box and then through tank with the nut on the outside. Should I use one or two gaskets? I can't figure out if I should just put one between the flange and the overflow box so it would go flange-gasket-overflow box-glass-nut or should I use two gaskets and have it flange-gasket-overflow box-gasket-glass-nut? I saw on gl*******s site that they use two gaskets with their box but they put the flange on the outside of the tank.

Clueless??

Gasket and flange in the box. Silicone between box and tank. Do not over tighten.

 

[cromag27]

Never use silicone with bulkheads.

 

[funkyrxman]

One of my overflows has a second bulkhead in it that was originally put in as a dry pvc pass through for cords. It has a 2" thread on the outside (bottom). I wanted to cut the dry pvc pipe in the overflow and put an elbow on the outside thread to use as a backup overflow to safely restrict overflow drain to reduce noise. No way to plumb to that outside thread on the bulkhead for a super short run of pvc?

 

[AZDesertRat]

The outside threads on a bulkhead are not NPT tapered pipe threads. Even if you could find something to fit over the outside it would leak since it is the tapered surfaces that seal as you tighten them up. Bulkheads are designed to use only the interior threads or slip/socket.

 

[Dave1045]

With a 1" Bulkhead and overflow- roughly how many gallons per hour can it support in siphon- to the sump?

 

[esquare]

AZDesertRat, i just got a stick of the plasto joint stick. I checked the SDS and it says it is a skin irritant, is this reef safe?

 

[AZDesertRat]

It does not carry a NSF label but I have never heard of any problems using it. More than likely it has not been subjected to the very expensive and time consuming certification process. Doesn't mean it isn't safe though.
LaCo has another product called Pipetite that does carry a NSF label if that is a concern to you though. It is more of a general purpose thread lubricant versus the Plasto Joint which is specifically for plastic threads. Not much difference though.

 

[esquare]

Thank you, I appreciate it.

 

[fragit]

@AZDesertRat, I need some help STAT! Just went down to my sump for something (diy 40 breeder). It's been running fine no leaks since last August(almost a year). My bulkhead is all of a sudden leaking. What should I do? I tried reseating it which did not work. I cleaned all surfaces and made sure they were dry. I don't have another one and will have to order one. Best thing I could come up with for a quick fix is to use some aquarium silicone and seal the outside. Do bulkheads suddenly fail often? Any guesses on how long my fix will last? What would your recommendations be?

 

[ca1ore]

FWIW, I only use slip bulkheads. May mean the occasional sacrificing, but less likely to leak than threaded ones. If you use threaded, no tape, use the liquid thread sealant. Although it should not be necessary, there is nothing inherently wrong with using silicone sealant. If I have an application where the bulkhead would be inconvenient to reset I will silicone it in (uninterrupted bead on both side of the gasket). Makes them tougher to remove certainly, but almost leak proof. I recently replaced my 25 year old ATO reservoir (an old plywood box) which had a siliconed bullhead from the start.

BTW, if you go to places like flex PVC they do sell bulkhead replacement nuts that are actually 90 degree fittings that will accept NPT piping. Never used them, so cannot vouch for how well they work, but in an application where rear clearance is a problem it's an option to consider.

 

[ca1ore]

With a 1" Bulkhead and overflow- roughly how many gallons per hour can it support in siphon- to the sump?

Depends on the 'drop'.

 

[Engloid]

I think water will siphon at the same rate, regardless of the length of drop. https://www.reef2reef.com/threads/1-pvc-flow-rate.125543/

 

[ca1ore]

It makes a HUGE difference. Think of drop as 'anti-head pressure' if it helps.

 

[KStatefan]

The velocity of the water will be the sqrt (2*g*h) where g=gravity and h=height the flow will then be v*area of pipe.

If you double the height you get about 1.4 times the flow.

 

[sportrax400ex]

Use RTV silicone gasket maker, I’ve had a few leaks and this can be used anywhere, to seal threads, to seal the gasket, and it is flexible and comes off clean for dissasembly. I’ve even started using it to stop air leaks on my air compressor lines, it’s better than pipe dope to seal, more flexible than regular silicone, and comes apart cleaner. Also reef safe so far.

 

[mniemann]

After applying plasto joint stick (which I found on amazon for anyone looking for it). Is there a set up time needed before water can be run through the systems?

 

[BZOFIQ]

Does anyone know how a modular marine ghost overflow is plumbed with bulkheads between the internal and external parts. Seems to be defying the consensus stated in this thread yet people report to leaks. Is there 1 or 2 gaskets on the bulkheads that connect the internal and external boxes?