Water Tank Repair

[fixer1958]

I picked up a water tank yesterday (used) that came with a trailer to haul it around in. I'd say the tank was about 350-400 gallons. The kind you stick in the back of a pickup. I'm sure the trailer was built for it. It's not going on the road, just around the property to water animals. Nice setup, been wanting one for awhile. My wife got it for $50.

Anyway there is a crack in the bottom about 2' long. I knew that going in to it. I used to weld plastic many years ago at a job but I don't want to spend $100 or so on the welder. Googling says to use fiberglass and the resin.
I know to sand it down pretty well and use a couple overlapping layers but I wasn't sure about long term adhesion. I'm not sure about the expansion rate of the plastic in hot and cold. The tank is white plastic.

Any experience with this type of repair?

[Huntinfamily]

Have you tried the JB Weld for plastic? I used it on a plastic water barrell a few years ago and it is still holding fine, no leaks. Not sure how well it would work with the weight of a couple of hundred gallons of water sitting on top of it but it worked great on a 55 gallon plastic water barrell. You can get it at Home Depot for something like two bucks and comes in a stick that you cut off the amount needed

[Bearfootfarm]

I'd use JB Weld and fiberglass tape, and if at all possible, put a layer on the inside too

[Common Tator]

Couldn't you use food grade silicone caulk? It is more flexible than the fiberglass, and will stick better too.

[plowjockey]

Originally Posted by Common Tator

Couldn't you use food grade silicone caulk? It is more flexible than the fiberglass, and will stick better too.

+1 on the silicone caulking.

It will handle slight stress and movement better than a rigid sealer.

[fixer1958]

I never really considered caulking. I may try that.
I wonder if I should try to stablized the split beforehand somehow?
It may make it worse though.

[plowjockey]

Originally Posted by fixer1958

I never really considered caulking. I may try that.
I wonder if I should try to stablized the split beforehand somehow?
It may make it worse though.

if it seems "floppy" enough, you could patch it with a piece of sheet metal and bolts and then "coat" it with plenty of silicone calking.

Silicone caulking, is as versatile as duct tape and WD40, in my world.

[fixer1958]

Yes it is.

[Common Tator]

When we bought our ranch 11 years ago, the 20,000 gallon water tank wouldn't hold water. Hubby removed the access port so he could go inside, scraped out about 4 inches of sand sediment from the bottom, and discovered a number of bullet holes in the floor of the tank. someone had climbed the ladder on the outside and fired a gun through the top access port, just to vandalize. Hubby cleaned up the holes and surrounding areas and used a generous amount of food grade silicone caulk. It has held all these years.

[SteveO]

I like the silicon idea but over it I would put a swimming pool patch or a waterbed patch to reinforce it. If it will work under 10 ft of water it should work for you. But you need to find out why you have a split and solve it maybe reinforce the area under it or that may be why it cracked?
Just ideas

[farmerj]

if you can figure out what the material it's made of, I have had good luck using parts of the tank and a propane torch to weld plastic tanks again.

[fixer1958]

I have one of those 250 gallon tanks in a cage that leaks like a sieve. I may take it apart and weld a piece of that on there. It's white plastic. I don't know if it's the same stuff or not.

Thanks for the ideas!

[awhobert7]

Silicone around it a sheet metal patch attached with sheet metal screws. So far lasted 2 years.

[PD-Riverman]

What I have done is clean the area around the split then use a piece of metal about 6" wide(have cut a piece of plastic out of a barrel and used it so it won't rust) and a few inches longer than the split. Drill holes about 1" in and about 1 1/2" to 2" apart all the way around the piece of metal/plastic. I drill all the holes through the metal and into the tank at the same time then I remove the metal and re-drill the holes in the metal slightly larger than the screws so when you tighten up the screws it will pull the metal up tight. I clean up everything again then use a good silicone and coat the whole area then screw down the metal/plastic to the tank and let it dry good for a couple days. Has always worked good for me.

Originally Posted by fixer1958

I picked up a water tank yesterday (used) that came with a trailer to haul it around in. I'd say the tank was about 350-400 gallons. The kind you stick in the back of a pickup. I'm sure the trailer was built for it. It's not going on the road, just around the property to water animals. Nice setup, been wanting one for awhile. My wife got it for $50.

Anyway there is a crack in the bottom about 2' long. I knew that going in to it. I used to weld plastic many years ago at a job but I don't want to spend $100 or so on the welder. Googling says to use fiberglass and the resin.
I know to sand it down pretty well and use a couple overlapping layers but I wasn't sure about long term adhesion. I'm not sure about the expansion rate of the plastic in hot and cold. The tank is white plastic.

Any experience with this type of repair?