Super sooper strong glue for plastic.

[Gingerbread Man]

The above is my cars heater matrix which is leaking.

It leaks from between two plates - where the inlet/ outlet pipe mount and the heater matrix body. It leaks due to flex and opening up slightly causing water to piss out.

I've tied gasket sealant and everything, the flex still happens even though it's bolts together. My plan is to glue the two plastic parts together. I need this to be a permanent weld that can cope with vibration and flexing, also to keep water in. I unfortunately don't know what type of plastic it is off the top of my head, I'll try find out.

I want it to be as strong as if it was one solid piece. What do I need to order?

[Gingerbread Man]

Would this do it?

Plastic weld

[motco]

To ask how to stick plastic is like asking how big is an animal. Some plastics are easy to bond and others are very difficult - they are all chemically different and even within a polymer type some have filelrs which make bonding harder. If it is polyethylene (not too likely) or polypropylene (more likely) it is difficult because they are both fairly inert. Frankly I think you'll end up getting a new matrix unless the section is thick enough to weld by hot air.