Fresh water tank repair

Hello Bill.....

Repairing cracks in "poly" plastics can be a real challenge. The first step is to make certain you know exactly what type of plastic the tank is made of. Then I would suggest you call 3M tech support for recommendations from them.

The black tank on my motorhome developed a small 1 inch stress crack. The tank is made of high density polyethylene. I quickly learning that nothing...and I mean NOTHING will stick to or glue HDPE. The only solution is plastic welding.

Plastic welding can be done relativity easy. There are 2 methods to use...hot air or welding iron. At a Harbor Freight store I was able to purchase a welding iron for $10 and it included a couple dozen poly rods. The rods are about the same size as a piece of spaghetti.

Next step was to practice plastic welding. I looked around the garge and discovered several items were made of HDPE. The letters HDPE are stamped on the item. I chose to practice on a plastic dustpan and found the process to be rather easy.

Now it was time to fix the black tank. In my case I was lucky the tank crack was assessable but I had to lay on my back and do so contortions. After an hour twisting my body every which way I was successful in repairing the crack. That was about 2 years ago.

Unfortunately now the gray tank has developed a small crack in the exact same location as the black tank. So sometime this week it is time to get out the $10 welding iron and do the fix.

Here is a link to Harbor Freight.

I bought the 80 watt kit when it was on sale for $10. Best money I ever spent. Give it a try.

I should also mention I learned much of this information as a result of a long telephone conversation with the engineer at the company in Indiana that manufactures the black & gray tanks in my motorhome. That fella had a wealth of knowledge & experience. It was he that said "NOTHING will stick to HDPE". The stuff was developed for that reason.

Hope this info helps you.

I repaired a 30 gallon fresh water tank on an old trailer of mine (cracked along the frame flange) and repaired it using a fiberglass repair kit (epoxy, hardener, cloth). I used to layers and it held. I used wire brush to scar the area first. Also I removed the tank to make the repair. It was a 2 foot crack.

Drill a hole at each end of crack and repair with JB Weld. Permanent fix.

They can be "welded" if not to old. The trouble will be finding someone to warranty their work.
You might call the rig manufacturer and inquire how much for a new tank. Fleetwood was able to provide a brand new tank for my 1990 MH.
Otherwise EBAY has many different tanks for sale on may fit your application

Tank-Depot.com

Call them and ask about repair products. You might even be able to look up the cost of a exact replacement tank.

Fred.