Water tank repair?

Question

Can anyone tell me how to repair a hole in a plastic water hauling container that is used to haul consumable water? It is a pretty big hole and I can't use anything that may be toxic.

Answer 1

If your tank is polyethylene (most potable plastic containers are, and they are usually stamped with a code to tell you what type of plastic they are made out of) you can use the same technique used to repair plastic kayaks (kayaks get jacked up all the time).

Here is a previous answer given by answerer "David in Kenai" concerning plastic boat repair.  Just substitute "water tank" wherever it says "boat."

David in Kenai, " I assume this is a polyethylene (PE) boat.

Propane torches are too hot.

You can weld PE on PE in several ways. The nicest way is with a hot-air plastic welding rig. It blows an adjustable temperature of hot air to pre-heat the boat plastic and feeds plastic rod to fill in the weld.

Ski bases are PE also, so ski shops sometimes have little rigs like that. But lots of shops just use the trick below:

The other, very cheap and simple way to do it is to pre-warm the boat with a hair dryer on "high" (so there is less temperature difference between the boat and PE filler materials. For the filler material, you can buy PE rod, or just cut strips from a yogurt container or milk carton (check the recycling symbol on the bottom that it is PE, LDPE or HDPE). Cut a strip about 1/2" wide and light one end with a match or lighter. Molten plastic will drip off the end (like a candle held sideways) and you drip it into the cut or hole or whatever you are fixing.

For a biggish hole, put layers of masking tape on the other side (to stop and pool the molten plastic). For any weld, orient the boat so the work area is level.

If you want to get fancy, you can find food containers or PE toys that are a similar color so the patch will look better. Or just use clear containers. There will be some soot in the patched area. But hey! What do you want for a repair that cost you a book of matches.

Wear leather gloves. Molten plastic doesn't stay hot long, but it sure can burn skin. Practice on thicker food containers or toys from Goodwill. Try pre-warming and not and then stress your practice piece till it breaks. See what works best for you.

Source(s):

I've done this on ski bases, PE kayaks, canoes, process equipment and toys. In ski shops, at home and on an actual desert island (Espirito Santos, Baja)"