# Bulkhead to PVC Threaded Connection



## fmueller (Jan 11, 2004)

OK, I am finally busy trying to get my 10' tank set up. There are a number of 1.5" bulkheads in the plumbing, which I bought at a quality plumbing store here in New Zealand, together with male threaded adapters going to PVC pipe. I glued the pipe to the male threaded adapter with PVC cement - no worries. The bulkheads are made in New Zealand and Hansen brand, but they are basically indistinguishable from what I used in the USA. The bulkheads themselves are also perfectly tight. It's the bulkhead to adapter threaded connection I am having trouble with. For the life of me, I don't seem to be able to get it drip free. I've spend days of reading on the Internet - make it tight, don't over-tighten, use Teflon Tape, use the good thicker Teflon Tape...

I've tried it all, but drip, drip, drip. Has anybody had any luck with these connections short of gluing them together? I would really like to be able to pull this apart for maintenance when necessary, but if nothing else works, I guess I'll just have to glue them together and make do. Maybe if I put Silicone on the threaded connection before screwing it together, I might even be able to pull it apart again. The last thing I need is my wife finding a puddle on the new laminate flooring I just put down!

Thanks for any advice!


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## caldwelldaniel26 (Jun 11, 2017)

Have you tried using the teflon paste or the thread sealant available at most plumbing supply stores? Both come in a can with a brush. I used this stuff called Blue Monster on my fittings. I got it for free from work but it's readily available online if you can't find an equivalent


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## fmueller (Jan 11, 2004)

Thanks, I read about that online, but the folks in the professional plumbing supply store here in New Zealand stared at me blankly when I inquired about it. I might have to order the paste from the US. It seems I am ordering everything either from the US or China :roll:


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## fmueller (Jan 11, 2004)

That's US$3.75 for the paste, and US46.55 for shipping. I think I will try something else first. It probably doesn't cost more than $5 to actually send this, but Americans do not like selling stuff overseas!


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## caldwelldaniel26 (Jun 11, 2017)

I'm sorry it's so expensive to ship! I'm surprised they don't carry some sort of thread sealant compound locally also. Did you try Amazon? They have it listed on there here in the states.


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## PfunMo (Jul 30, 2009)

Plastic plumbing does have some weird little things that need different methods. How does the leak start? Is it there due to the fittings not quite sealing right away or is it something that occurs after a time like a week or more? 
For the first. I normally find the threaded fittings do okay with three laps of the sealing tape. Several types of the goop is not to be used on plastic as it can have a chemical reaction. Something to check as there are specific sealers for plastic if you want to go that way. 
However, if the leak is something that comes around after the fitting has been in place for a while, I now do plastic drains differently. I do not try to go with them dry as designed as I find the plastic has a much higher rate of movement when heated or cooled and it does cause leaks in traps and places like that. I find keeping a tube of clear silicone in the toolbox is worthwhile and just automatically add some to the threaded fittings on plumbing. It can make getting a trap off just a bit weird but still works well. The weirdness comes when you turn the fitting a bit and it moves back to the original position. I have to turn it far enough to actually break the sealing silicone loose which is different! Also putting it together takes a different move as I have to give the silicone plenty of time before testing. Since it is enclosed and the fumes can't gas off in the normal way, this may need to be the next day before hitting it with water. Water can just wash the silicone out if done too soon but it does make a super nice, long lasting seal. I've not found any silicone that degrades the plastic.


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## fmueller (Jan 11, 2004)

Turns out I made the rookie mistake of relying on info by the store, when I should have checked the manufacturer's web site. The makers of the bulk heads recommend a special sealing paste, which is Loctite 5331. Almost as expensive as the Blue Monster with shipping, but these connections are not something I am keen to take a chance on, so I've ordered it.

No sellers on Amazon is prepared to ship Blue Monster to NZ. I used to be a prime customer when living in Ohio, so I can still go on the site and see I would have gotten it for peanuts there with free overnight shipping 

I've talked to folks here, and they say Silicone does not work with these bulkheads. I have a hard times seeing why not, but again, better not take any chances. So far my leaks came on right away, but before I found out about the Loctite, I tried acrylic caulking. So far it's perfectly tight, but as you say, who knows what happens after some months.


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## caldwelldaniel26 (Jun 11, 2017)

Yeah, the cost is well worth the peace of mind knowing your tank isn't going to leak. I didn't think about loctite but that should definitely seal the threads.


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## gillmanjr (Jan 27, 2017)

I had the same issue with the Eshopps overflow box that I bought, one of the bulkheads was dripping. Teflon paste fixed the problem, thats what you need.


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## greid (Jul 25, 2017)

Did you find an alternative to the Loctite 5331?

I had the same problem with other threaded pipe with my sump. 
Used the thicker teflon tape and cranked it as far as I dared (very slowly) but was afraid I'd crack it.
Definitely prefer glued joints.

I looked into pipe sealant but couldn't find any for use with plastic locally (London, Ontario, CA).
Graham


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## fmueller (Jan 11, 2004)

I've mail ordered Loctite 5331. Cost me about NZ$50 ( about US$35) for a smallish tube, but works like a charm. Connections are 100% drip free, 100% of the time. Worth every penny to me!


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## greid (Jul 25, 2017)

I found a source for - Loctite® No More Leaks™ Plastic Pipe Sealant - cost was going to be $47 CA.
Did some digging & I think the following should be fine: Cost $16 CA

"MASTERS® PRO-DOPE® is a non-toxic, non-corrosive, non-hardening paste. It effectively seals both metal and plastic threaded connections. It will not dry out, stain, harden or separate. Lubricates during assembly and can easily be disassembled even after years of service.
MASTERS® PRO-DOPE® effectively seals most liquids and gases against leakage to 10,000 psi and from -200°F to +400°F (-129°C to +204°C)."

http://www.gfthompson.com/ProductSheets ... 202015.pdf

Graham


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