The product to use is Fusor 133 Plastic Repair Adhesive - ph.parker.com/au/en/product-list/fusor-132-133-plastic-repair-adhesive-super-fast - It's a two part epoxy used in Auto Repairs. Clean area with solvent and lightly sand, you may have to open the crack to allow penetration of the 133. www.ebay.com.au/itm/363909325002

Google 'how to repair a polyethelene water tank' and this is what you get

The best way to fix a hole in a poly water tank is with the use of a professional plastic extrusion welder. With a plastic extrusion welder, you inject molten polymer rod into the hole via a bull-nose tip (part of the machine).

deverall11 wrote:

---

Google 'how to repair a polyethelene water tank' and this is what you get

The best way to fix a hole in a poly water tank is with the use of a professional plastic extrusion welder. With a plastic extrusion welder, you inject molten polymer rod into the hole via a bull-nose tip (part of the machine).

---

 Correct. I'm a gummint certified plastic welder now retired.

woolman wrote:

---

It is possible to repair a plastic tank with an electric soldering iron. You need some of the same plastic to be able to add more bulk to the weld. 

I have successfully done this myself so can work, providing no moisture can interfere. We had a 12 volt poly pipe welder that joined pipe in a joint stronger than the pipe itself, hence discovering how easy plastic is to repair.

 

Neil 

---

 That's what I did to fill a few no longer needed holes in my Sit On Top Kayak.  Easy Peasy & still OK 10 years later.

As seen on TV..Flexseal. My Son repaired a 55000 ltr tank with it. 15 months on still good.

RobDor wrote:

---

Have a small crack about 2cm long in poly water tank (its a 127litre tank). Is there a product that will repair the crack ? What do you recommend please ? Also, would you know where to source a new tank if repair is not an option. Many thanks

---

Hi RobDor

I was in the same boat as you, a small crack in my water tank, and found that for whatever reason, that I could not buy a new tank, of the same awkward Jayco shape (80 litres)

My research led me to believe that RV water tanks are made from polyethylene plastic (I saw no plastic type numbers on my tank, as I did not remove it) 

I brought some polyethylene plastic from a local plastic repair mob, and used a normal (cheap from Bunnings) 240 volt 80 watt soldering iron

I cleaned the (dry) area with Isopropyl Alcohol Cleaner, also from Bunnings, but not as cheap as the soldering iron

I managed to fix the leak, by following utube plastic welding, (I did not place any stainless mesh over the repair, as I had none)

The repair has held so far (about 18 months)

As a matter of interest to others, (I was experimenting, err playing around)

Using a 300/600 12 VDC to 240 VAC, inverter from my batteries to the soldering iron, I was pulling just over 8 amps out of the batteries
I repaired the water tank, with the soldering iron running through the inverter from the 12 volt batteries 

Therefore in my opinion, any plastic repair mob would be able to repair a RV water tank