Sand filter leaking from dome

[singerteacher]

First off, this is my sand filter: Hayward S200 side mount with clear plastic dome

http://www.walmart.com/ip/Hayward-High-Rate-Side-Mount-In-Ground-Pool-Sand-Filter-S200/44591448

Background: The sand filter was not leaking before we deep-cleaned the sand by unscrewing the plastic dome on top, running water into the sand, etc. Unfortunately, when we put the dome back on, it began to leak from the dome. Not a horrible leak, but visible and worrisome.

So, we bought a new o-ring, cleaned out the threads, added new lubricant, put in the new o-ring, and put the dome back on, tightly. Turned the pump on, and it is now REALLY LEAKING. Badly.

Yes, the dome is on tightly. Yes, the o-ring is seated correctly. Yes, we used pool lubricant. I believe that there must be small fractures in the threaded area near the dome, and that they got worse the second time we messed with it. I'm at a loss as to how they suddenly occurred -- apparently, just unscrewing the dome was enough to cause them? At any rate, we're looking for solutions that don't involve dropping $800 for a new filter.

Do we have any options? Is it a good idea to just replace the top half of the tank, since that's the part that leaks? I've read here about 2-part epoxy, but if every time we unscrew/replace the dome it causes cracks, I worry that it will just get even worse.

 

[cowboycasey]

that sucks that it's leaking, inyo pools has a breakdown and can order all the parts.. I take it you changed #4 on the diagram.. do you think its #3 leaking or #5,

Hayward S-200/ S-240 Sand Filter Parts - INYOPools.com


I hope this helps

 

[duraleigh]

That dome should not be as tight as you describe. You may have overtightened it and cracked it.

Let's certainly hope not but the next thing to do is take the dome back off and inspect the dome and filter body for evidence of cracks. Report back.

 

[rdshackleford]

For certain thread leaks, I have had good luck with Oatey Megaloc w/ Kevlar thread sealant where other things have failed. Ymmv.

Also, notice the seat on the dome flange that matches with the shell. Especially if there is play in the threads, the seat has to match up or it won't clamp down on the o-ring.

 

[singerteacher]

The cracks are in the tank, not the dome. Very tiny cracks. We purchased a special wrench to get the dome off without damaging anything, and it went back on smoothly both times. I don't think overtightening was the problem, because after the first time replacing the dome, when it leaked instantly, we were able to tighten it a bit further (which didn't stop the leak). I will say it is a very old sand filter, and we had never opened the top before in the 8 years we've owned the pool. Not sure if previous owners did or not.

The dome itself is not cracked at all. I wish that was the problem - much cheaper!

Does anyone have experience in replacing the top half of the tank only? Also, why in the world does INYO have the top half going for two different prices based on color? Is the material different? If so, is one kind of material superior to the other?

 

[cowboycasey]

they are 2 different sizes, you could actually get the bigger top and have a bigger sand filter

 

[cowboycasey]

it looks like the bigger one is discontinued everywhere

 

[rdshackleford]

JB Weld? I fixed spider cracks around my pressure gauge port with that.

 

[duraleigh]

I am not part of the "don't run with scissors" crowd, but I would not repair a fibreglass pressure vessel. The filter body "flexes" and will eventually fail about any patch.

Even at only 20 psi or so, you don't want your filter to explode. (and it probably never would) I would get a new one and have no worries.