Adhesive for nylon in radiator bottom

[Tinhack]

I've never had good results with trying to fix radiators. The primary negative is never being able to get all the coolant out of the crack. Nothing will stick if there's even a minutus coating of coolant left in the crack. Even if dry.

 

[mikester]

If the plastic is "perfectly clean" and "new" you could try plastic welding or epoxy.

I know that I would never be able to get an older used plastic rad perfectly clean.

In the good old days I'd take it to the radiator repair shop and have them replace the broken bits. We are a throw away society now and I can't find anybody that does these repairs anymore. I'd throw that rad away and buy new...way cheaper than replacing or rebuilding a cooked diesel motor.

 

[rScotty]

If the plastic is "perfectly clean" and "new" you could try plastic welding or epoxy.

I know that I would never be able to get an older used plastic rad perfectly clean.

In the good old days I'd take it to the radiator repair shop and have them replace the broken bits. We are a throw away society now and I can't find anybody that does these repairs anymore. I'd throw that rad away and buy new...way cheaper than replacing or rebuilding a cooked diesel motor.

Like most older mechanics, I welded, brazed or soldered as required. If I was replacing a plastic radiator, it would be with one that could be repaired. Old copper and brass radiators are easy to repair, same for older soldered copper plumbing in the house. Anyone can do it.

 

[zzvyb6]

I've just used a 'plastic' welder to fix radiator support brackets on a car radiator. This is the hot wire type of reinforcement that will help with strain relief (movement). I'd put at least 3 in that crack and another on the back side, again: for strain relief. Then use 2 part epoxy to seal the leak.

 

[paulsharvey]

Find out the part number for the radiator and google it. I use the format "xxxxxx Kioti" or "xxxxxx radiator" and usually get good results. If you come up with alternate/updated part numbers, make sure you google those too. Sometimes that gives better results than the original part number. If you can find an after market replacement I'm thinking the price will be around $200. That's my guess. Good luck.

I did do some searching, and I have no doubt there is a generic Honda race radiator or similar that could be fitted. I also did some searching to just replace the bottom tank, which is just crimped on, but i didn't find a definite fit.

 

[paulsharvey]

Again, you sure it's nylon and not extruded structural fiber? I do know that Modine (who makes a ton of radiators for all sorts of applications) uses structural fiber for their upper and lower tanks on rads today and the tanks on their rads are sonically welded to the aluminum heat exchangers are cannot be replaced. Even oil pans on commercial diesel engines today are structural fiber, pressure die cast.

Sadly, the days of copper alloy rad cores and upper and lower tanks are gone and are in reality better because they can actually be repaired and re-cored. The new rads cannot be, so replacement is the only option.

Im not really sure what extruded structural fiber is? These tanks are definitely crimped, not welded to the aluminum core.

 

[paulsharvey]

So, I stopped and got the Plast-bond JB weld, seems worth a try. Gouged out the crack and roughed up the area, cleaned with alchohol and added a thin layer. Gonna let it do a 24 hr cure, or atleast 16, and then reinstall and test. Definitely will keep an eye on it, and might replace at somepoint.

I have used some incredible epoxies at work, upto 9000 psi to bond brocken structural concrete to new, so, I dont doubt the correct epoxy is capable. I just don't know about thermal expansion, ect, and what matches the parent material.

 

[sandman2234]

Good luck, hope it works!
David from jax

 

[frogpond]

I have had good luck with cracked nipples like this with 3M 5200, a polyurethane goop which holds on practically everything. I would build up a thick fillet around it. Let it cure for a day or two. It's close to indestructible, and shock resistant. You can reliably glue a boat together with it. I have not used it in hot applications, but you could ask 3M. Marine stores like West Marine carry it

 

[paulsharvey]

I've been working at the old house getting it ready for sale, and it's been raining all day today, so...

My plan, I'm going to run it for 45 minutes, above idle, but below PTO speed, to check the repair, but I want to watch it for that 45 minutes. Not start it and get distracted, and come check on it later... If that holds, I'll drain the water, and put 50/50 back in, run for another 45, and return it to work.