Help: punctured water tank

[40tahitian]

I may be showing my age, but does any one remember the roofing nails for galvanized sheeting, they had a rubber pad under them to make a seal, the modern version for a metal roof and siding is a non rusting self taping screw with a sealing pad under the head, you could even put a dab of sealer under the head like Automotive Permatex, non hardening kind, I think it would work.

[a64pilot]

Your not showing your age, those are the new type of nails. The old type have a lead covering over the head.

[Compass790]

My 2c worth is an o-ring under screw head. Don't over-tighten

[clockwork orange]

Originally Posted by a64pilot

Your not showing your age, those are the new type of nails. The old type have a lead covering over the head.

Damn, you beat me to that lead head thing. But yes, if they are SS that would be a good one. Some of these tanks have a significant wall thickness, I replaced a water and a holding tank on a customers boat this summer and I think they were either 5/16 or 3/8 so plenty for either tapping for a machine screw or a self tapper of any pitch. I would still put a dab of sealant (not adhesive) under the head or the rubber washer.

[Sardean]

A bit of teflon tape around self tapping screw and she'll be right mate

[Empty Pockets]

You can weld a small hole easily with just a soldering gun and a piece of milk jug or six-pack rings as mentioned earlier. Then it’s fixed, not plugged...

[ebsail]

Stainless sheet metal screw with a rubber washer under the head

[john61ct]

Originally Posted by Empty Pockets

You can weld a small hole easily with just a soldering gun and a piece of milk jug or six-pack rings as mentioned earlier. Then it’s fixed, not plugged...

+1, if tank is HDPE like milk jugs

[Tbonem17]

You could sit there with your finger over the hole and when that wears out change fingers. There is never enough time or will to do something right the first time yet there is always time to do it again. Weld the thing up and if you need to ask how then use your finger instead as that will always be more successful. Most plumbers should be able to weld it or better still are the mobile plastic repair people who mainly advertise themselves for repairing car bumpers. Every car yard and panel shop will have contact details for the local (professional!!!!) guy. Then you have the civil contractors laying pipe and the people lining manholes with poly etc etc. You could pay the retail rate or offer someone some liquid inducement or a day out on the water for an after hours job. The later only works on employees and never the boss. With reasonable access it's a half hour job and most of that will be spent waiting for something to heat up.

[Tbonem17]

Further to my previous post I've just retired after spending the last 40 years welding poly mostly in pipe fabrication. If anyone had come into our workshop looking for a repair job on a water tank with the lure of a day out sailing as payment then people would have lined up to help. Hell the opportunity for a look around and a chat about boats would have been enough inducement. Actually getting to go out sailing would get your tank fixed and all your plumbing custom designed and replaced too. There are many trucks in my vicinity driving around with under tray water tanks made out of scrap for the price of a few drinks and boredom relief.

[john61ct]

What is the name of that category of shop in order to find them in google or YP?

[Jerry Woodward]

Thanks for all the helpful ideas. For better or worse, here is what I did:
I screwed a stainless 1/4" pan head screw into the hole through a small pad of Bed-It butyl tape (the good stuff from Main Sail). I tightened it just enough for the butyl to ooze out around the head of the screw. Its been two days now with a full water tank and no leakage. I will continue to monitor it over the course of the season. I figured I can always remove it later and do a proper weld job for a more permanent solution.


Thanks again to all!

[Rod B]

Check the internet for info on spinweld fitting and installation. When I ran a rotational molding plant we used them on polyethylene tanks all the time. This goes for anyone looking to install a fitting in a PE tank.

[Cheechako]

-Thread/tap the hole and install a machine screw
-I would think aquarium silicone would work.

[Jim Cate]

Originally Posted by Jerry Woodward

Thanks for all the helpful ideas. For better or worse, here is what I did:
I screwed a stainless 1/4" pan head screw into the hole through a small pad of Bed-It butyl tape (the good stuff from Main Sail). I tightened it just enough for the butyl to ooze out around the head of the screw. Its been two days now with a full water tank and no leakage. I will continue to monitor it over the course of the season. I figured I can always remove it later and do a proper weld job for a more permanent solution.


Thanks again to all!

Well done, mate! You have done a good job of sorting out the wildly varying advice and come up with a practical and verifiable solution to your problem.

I make this comment because so many times innocent and simple problems get so overthought and over solved here on CF that the poor OP just goes away in despair.

Again, well done!

Jim