How Repair Hairline Crack in Nexus?

[MikeM]

For the past few months I've found a wet or moist spot in the filter pit at the base of one of the Nexus filters. It wasn't much, but it has bothered me. However, some days everything was bone dry. Perhaps a little bit of spray from a yard sprinkler was getting into the pit? Checking it out, I determined that was not the cause. I went over every pipe connection and found nothing leaking. What was really troubling was that the moist spot was only irregularly present. There would be no sign of anything for days, and then there would be again. I was squeezed under the Nexus units a few days ago checking all the pipes and connections again when I thought I felt a drop of water land on my back. At first I thought it must be a leak at a connection that is on the underside of a Nexus, but that was dry. I was beginning to think I had imagined the drop, when I saw it... a hairline crack on the underside of the outer Nexus chamber. The 'fracture' is perhaps 0.75" long. There was a dark spot (between the 'kiss points') where a single drop of water emerged. On that occasion, it was dripping at a rate of one small drop every 6 or 7 seconds. The attached photos show the before & after of a single drop of water emerging. The hairline crack cannot be seen in the photo, but there is one.

I think I've read everything on the EA website and find nothing about how to fix such a thing... probably because it should not happen! Since discovering the drip, I have observed the 'spot' frequently. Usually there is no drip and no sign of anything wrong. If I did not know to look for the hairline crack, I'd never see it. (Presumably temperature or some pressure/stress occurs that is related to the hairline crack opening just enough for a single drop of water to get through and later it stops when that stress factor is not present.) I want to apply a repair now, because I am concerned that over time whatever caused the little crack will cause it to become bigger. I have a couple of ideas in mind, but before wasting time on useless or second-rate fixes, I thought it best to ask for advice.

Suggestions?

[luke frisbee]

MikeM,
I can actually give you some good advice on this

it can be easily fixed.
The BEST person to fix it is a place that deals with Kayaks, especially Renting kayaks. however if you watch them repair one of their boats you will be able to do it .
imagine they have to make the Crack stronger than before cuz the next knuckleheads life depends on it...
I am fairly certain the Nexus is made of the same stuff as the Hydra Vortex chambers, and I "melted/repaired one of mine three years ago and it is fine now...and I did a butcher job on it.
Yuo might wanna pay the guy to come repair it for you (You're Rich..and picky). But all I did was take a heat gun and warm it up so it was "waxy/melted and while I was doing that I took a scrap (the kayak place has plenty of scrap because they cut stowage holes in the boats they get...they also make repair sticks if you wanna go that route.
I then melted some more of the plastic it might be HDPE and glued some of the scrap I got from the kayak guy over it on the inside and out. i went way over board. but then I didn't feel competent, and felt that it would fail soon...it hasn't.
But like i say...see a Kayak retailer/rental guy and he should be able to help you out.

[luke frisbee]

Another guy you might want to call would be a Spa guy...Home spas are made of the same stuff, and of course people are rough on them too.

Plus a spa guy will make it look pretty, and will be more likely to make a housecall.

[JasPR]

Mike, I had two leaks in my fiberglass indoor pond. They were both around the PVC buldheads and the fiberglass surface itself.
I talked to Mat McCann who put me onto a two step epoxy cement. It worked beautifully! No leaks after living two seasons with a drip that lately became- more than a drip! The stuff sets up quickly and is hard in 6 hours. I have had the fish in contact with it for two weeks now with no problems. As Mat said, it is a small amount in contact with thousands of gallons of water.
Anyway, good stuff. It is used in the plumbing industry for patching leaks in leaking pipes but is also used to repair marine hulls- so a boating supply place will have it. Goes by several names - plumber's fix or also known, appropriately enough, as ' the good stuff' All crafts professional epoxy for potable water.

works on PVC, fiberglass, glass, ABS, wood, Hard Rubber, Cement----

JR

[luke frisbee]

BTW we really didn't need to see a pic of your leaking crack

[MikeM]

Thanks, guys!

Yeah, Luke; but if somebody had the same thing happen, they'd be able to see it was the same.

[Eugeneg]

[ I have a couple of ideas in mind, but before wasting time on useless or second-rate fixes, I thought it best to ask for advice.

Whether it be a boat or drain what I always use is a plummers repair stick .
You tear a piece off and kneed together and stick on . Works a lot like epoxy . You can also get the same at a local marina at 3 times the price but has a picture of a boat on it .
Regards
Eugene

[Nancy M.]

Ken, at Eastern had a Nexus that the side wall, when manufactured was defective, the wall was so thin you could see through it. Burt Ballou came over and cut the section out and fiberglassed it. No leaks been running for a little over a year. So I guess you could fiberglass it.

[PapaBear]

For stuff like that I've used the same epoxy JR mentioned, but I always like to bed in some fiberglass repair tape with it. Call me obsessive, but the extra strength of a wee bit of glass embedded is worth the minuscule effort. The plumbers putty epoxy sticks work pretty good too. It is fundamentally the same as JB Weld.

[bekko]

HDPE is one of the hardest materials to get anything to stick to. Epoxy will work as long as nothing ever moves. If there is movement it will pop loose.

When there is some movement expected, something like silicon may work better because it has elasticity. Aquarium silicone will last for many years under water but the silicone from the hardware store will fail in about a year.

The weld (melt) method is more permanent. Besides the aforementioned, anyone who does auto body repair will be proficient at welding HDPE. You will need to dig out the crack a bit so the edges can be beveled. Otherwise, the weld is just sitting on top and will not be as strong.

If it were me, I would just ignore it or put a pail under the filter to catch the drip. If the crack grows, it will grow slowly and give you plenty of time to react. When/if the time comes, repairing a 3-inch crack will be no more difficult than repairing a 3/4-inch crack.

-steveh opki