HELP !!! POLY to PVC BULKHEAD LEAK

[barryian]

Hi All - I just built DYI F filter for a friend who couldn't spend a fortune on filtration. I used a 55 gallon poly drum (pics below).
I used 3 bulkheads, one 1-1/2" cleanout on bottom, one 1-1/2" intake on the bottom & one gravity 2" return on the top. I used
3M 5200 marine adhesive in the white quick dry (24 hour) set. I used this for everything for years.

Problem is the bottom 2 bulkheads are leak by the 3m 5200. One's a slow drip and one is a fine squirt. I'm amazed but now thinking it doesn't bond to poly. All my fittings of pvc are glued and fine. The flow out the top is amazing ....

Would anyone know what I can use to go over the white 5200 to seal the bulkheads to the poly container? Possible PL Roofing and Flashing sealer? Any help would greatly appreciated. Thanks so much ....

 

[carolinaguy]

Tough question. It would work better if the seal could be used on the inside so that the water pressure helps to seal. If you have an EPDM fragment, then cut the fragment to form a hole with no rat tails and slightly smaller than the pipe. The fragment should be a couple of inches larger than the pipe. Use Lexcel (ace hardware where we live) to coat the surface of the fragment and press against the inside of the barrel. Surfaces must be dry. Tighten the bulwark fitting to compress and let dry for a day or so. Might work. I used Lexcel on my bottom drains with no problem at about 4 feet of water.

 

[sissy]

The reason they do not seal well is the bottom of the barrel is more rounded .There is a bulkhead that is an odd shape but have not seen it for a long time .Did you try plumbing tape or the plumbing sealer for pvc even a thick rubber gasket may seal it .When the hole is cut with a hole saw it will cut an uneven shape in a rounded barrel

 

[barryian]

Tough question. It would work better if the seal could be used on the inside so that the water pressure helps to seal. If you have an EPDM fragment, then cut the fragment to form a hole with no rat tails and slightly smaller than the pipe. The fragment should be a couple of inches larger than the pipe. Use Lexcel (ace hardware where we live) to coat the surface of the fragment and press against the inside of the barrel. Surfaces must be dry. Tighten the bulwark fitting to compress and let dry for a day or so. Might work. I used Lexcel on my bottom drains with no problem at about 4 feet of water.

Thanks. Sounds like I'd have to somehow, if even possible take this all apart. When you say " fragment ", you're referring to what?

 

[BlueOrca]

I have had great results with that marine adhesive, I usually scuff up around the hole in the poly with an abrasive pad or sandpaper (dremel works too) for better adhesion. Just an observation from the pics is that is seems most of your adhesive is on the bulkhead nut and not a bead around the seal area (where it would leak) Use a generous amount and spread it with your finger for better results. Not sure if new caulk will stick to old caulk btw....

 

[BlueOrca]

Thanks. Sounds like I'd have to somehow, if even possible take this all apart. When you say " fragment ", you're referring to what?

Rubber liner patch I think he is referring to...used as a gasket.

 

[poconojoe]

3M 5200 is strong marine grade stuff. It's gotta be that poly material. Maybe too smooth to adhere to. Maybe you can rough it up with course sandpaper and try again? Just curious, why did you use sealant? Didn't your bulkhead fitting come with a gasket?

 

[barryian]

I have had great results with that marine adhesive, I usually scuff up around the hole in the poly with an abrasive pad or sandpaper (dremel works too) for better adhesion. Just an observation from the pics is that is seems most of your adhesive is on the bulkhead nut and not a bead around the seal area (where it would leak) Use a generous amount and spread it with your finger for better results. Not sure if new caulk will stick to old caulk btw....

I've used it for years and like you never had a problem. I did use it inside and out all around the bulkhead at the container and then threaded the piece tight. I was shocked to see these 2 leaks. If I can actually remove the 5200, the sand and scuffing sounds like a good idea. I'm hands on everything but that was an over sight. With 375 lbs of water, the pressure is a lot down at the bottom. Thanks BlueOrca. Much appreciated.

 

[barryian]

3M 5200 is strong marine grade stuff. It's gotta be that poly material. Maybe too smooth to adhere to. Maybe you can rough it up with course sandpaper and try again? Just curious, why did you use sealant? Didn't your bulkhead fitting come with a gasket?

Yes, they have the gasket on one side only but the curve left gaps even when tightening with a wrench. Can't over
tighten or the gasket with crunch. Thought this was going to be a walk in the park. Might need 2 new bulkheads.

 

[carolinaguy]

Thanks. Sounds like I'd have to somehow, if even possible take this all apart. When you say " fragment ", you're referring to what?

A piece of EPDM maybe 6 to 8 inches square or round. The important detail is making the cut round with no cuts that might tear. A brand new utility knife blade keeps the cut smooth.

 

[Jhn]

Agree with carolinaguy, flip bulkhead around with gasket on the inside, nut to tighten on the outside. Water pressure will help seal it.

 

[barryian]

A piece of EPDM maybe 6 to 8 inches square or round. The important detail is making the cut round with no cuts that might tear. A brand new utility knife blade keeps the cut smooth.

I just ordered 2 new bulkheads. Somehow, I'll have to get these off. Are you saying, put the gasket inside with no sealant? Then use the EDPM on the outside? If so, I would need several layers because of the curve in the 55 gallon drum .... The drum and the gaskets are poly. Obviously the 5200 doesn't adhere well to poly. Should the bulkheads come with 2 gaskets??? Can you clarify ... Thanks as I appreciate the help. Last time I used a bulk head was on my Savio 5 years ago going to a underground tank for overflow. No pressure so no problem.

JUST EDITED THIS : Just removed one bulkhead. The 5200 didn't even stick. Peeled off clean. Doesn't take to poly whatsoever. Probably better using nothing but gaskets on inside and EDPM on outside as a gasket as you suggested. Thoughts?

 

[Jhn]

Yes on bulkheads the gasket goes on the inside, the nut to tighten goes on the outside. Some bulkheads come with two gaskets, some one.

Thinking about it more, really standard bulkheads aren’t great for curved surfaces. A more effective bulkhead for curved surfaces is a uniseal bulkhead. Just a rubber gasket that shoves in the hole then pvc pipe shoves in through that, creating a water tight seal.

 

[barryian]

Yes on bulkheads the gasket goes on the inside, the nut to tighten goes on the outside. Some bulkheads come with two gaskets, some one.

Thinking about it more, really standard bulkheads aren’t great for curved surfaces. A more effective bulkhead for curved surfaces is a uniseal bulkhead. Just a rubber gasket that shoves in the hole then pvc pipe shoves in through that, creating a water tight seal.

I'm starting to think after seeing how the 5200 came peeling right off, I should have used the think washer inside without 5200. I can't use the uniseal at this point as my holes are cut through from the 1-1/2 inch bulkhead ( 2-1/4" hole) and the 2" bulkhead ( 3" cutout ) so I'm locked into these. The new ones are ordered. I believe which I find hard to believe, lol .... that the 5200 on poly caused the problem .... Thanks for all the input to everyone....

 

[GBBUDD]

I haven't read all the responses here but if you use a new bulked it should come with a cardboard or cork and a rubber washer these alone should do the job if cleaned and tightened properly and not over tightened.