Questions on PVC and internal overflow.

sweatervest13

sweatervest13

Active Member
So I have a build thread going here but I have a quick question on some things and I thought this might get more looks quicker.
I am having some issues with leaks on the PVC system draining and returning water from the tank's overflow to the fish room. I have about 10-12 feet of PVC for each line and most of it is connected well.
I have/had an issue with the return line going into the bulkhead. The bulkhead is a 3/4" threaded (inside and out on the side that is sticking out of the bottom of the tank) and threaded on the side that is in the overflow. This goes to black tubing that runs to the spray out connection. The bulkhead is trashed now and the new one is a bit different. It is threaded only on the outside of the dry side the other fittings are slip. Because of this I need to redo the inside of the overflow part. Can I just use solid 3/4" PVC or do I need to use flex-able tubing like was in there before?? I can't think of a reason why I could not. But I figured before I glue all this together I would ask here to see.
Next is the fitting of the bulkhead to the PVC. Before I used a connection that screwed into the bulkhead. This leaked and would not allow me to tighten the bulkhead. Every time I tried to tighten it would just twist the bulkhead making more leaks. WHAT A MESS!!!. So I was kind of happy to only find the style of bulkhead with a slip fitting on that side. So I will be gluing into that. Can I also use silicone to help with the fittings? How long will I need to wait for everything to dry before testing?
Any help/feedback is super appreciated
 
saltwaterdud3

saltwaterdud3

Member
Alright, after reading your post a few times to make sense of it...
The FTP fittings should always have teflon tape wrapped around the threads before you screw it in. This kind of lubricates and seals the threads so you don't have any leaks. The best way to do PVC work is to use both a primer and the cement. You prime it, let it semi dry and then you cement it liberally. After you push it into the joint, your supposed to give it a one quarter turn to make sure the cement makes a strong seal.
Silicone will not help seal off PVC. I wouldn't do that. Also, you only hand tighten bulkheads and when you can't get it any tighter by hand, you only give it 1/8th of a turn with pliers to completely seal it off. Too tight and it will leak. Obviously, too loose and it will leak as well.
 
sweatervest13

sweatervest13

Active Member

Alright, after reading your post a few times to make sense of it...

The FTP fittings should always have teflon tape wrapped around the threads before you screw it in. This kind of lubricates and seals the threads so you don't have any leaks. The best way to do PVC work is to use both a primer and the cement. You prime it, let it semi dry and then you cement it liberally. After you push it into the joint, your supposed to give it a one quarter turn to make sure the cement makes a strong seal.

Silicone will not help seal off PVC. I wouldn't do that. Also, you only hand tighten bulkheads and when you can't get it any tighter by hand, you only give it 1/8th of a turn with pliers to completely seal it off. Too tight and it will leak. Obviously, too loose and it will leak as well.


I had to reread it a few times as well. First time doing PVC if you could not tell. Lol
Thanx for the advice. I didn't do the 1/4 turn after cement but those connections are not leaking. I will keep that In mind going forward. I had heard that about the bulkheads. So it should not be a problem doing a regular PVC in the overflow cemented in both sides of the bulkhead?
Thanks
Ryan
 
2quills

2quills

Well-Known Member
If you still want to use the flexible plumbing with the slip bulkhead...get a slip by thread coupling and a short piece of pipe and glue it in.
 
saltwaterdud3

saltwaterdud3

Member
Great advice 2quills.
Eh, what I've done in the past when coming up on that problem is cementing in a piece of PVC in the slip and then putting a vinyl tube over it and hose clamping it down really tight. That usually works especially if teh line is not under an extreme amount of pressure.
 
achilles tang

achilles tang

Member
darn wish i knew this first lol. but i used PVC cement and those circle claps and i don't have any leaks. super happy now lol. but I'm defiantly ganna keep this tape in mind for my next tank :)
 
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