Adhesive for nylon in radiator bottom

[paulsharvey]

What adhesive, epoxy, plastic weld, ect, would be a good product on the nylon portion of a radiator? It's not a puncture, it got hit, and cracked where a bottom "peg" attaches to the tank.

It's actually odd, funny, ironic? But I was backing up, and the way a rear tire lifted a limb, smacking the bottom right of the rear of the radiator. New radiator is $600, so that's not gonna happen. I actually assumed it was the smaller, lower radiator hose, as I've seen multiple reports of that being a weak point, but in my case, that's not the issue.

 

[paulsharvey]

Pictures of the damaged area

 

[RjCorazza]

I have had good luck with the various formulations of JB Weld. I'm sure they have an epoxy product for your application.

 

[paulsharvey]

I have had good luck with the various formulations of JB Weld. I'm sure they have an epoxy product for your application.

I have tried JB weld on a metal one years ago, with not good results, but that could have been prep/cleaning.

I've seen reports for super glue, cylo-something, but typically super glue doesn't hold up to high temps, also not sure if the liquid part is good, to get down in the crack, or build up; or maybe high temp super glue in the crack, with JB on top, maybe?

 

[RjCorazza]

I have had practically zero good results with super glue type adhesives on plastics. I was able to super glue coroplast plastic sign material years ago, but it required a very specific "flaming" technique (for lack of a better term). That's not necessarily related to your nylon material though.

 

[paulsharvey]

Looks like JB Weld, Plastic Bonder, is likely worth a try. It says it does bond to nylon, and is rated to 250 degrees F.

 

[paulsharvey]

By all means, if that is a bad idea, an unsuitable product, or there is something else that is readily available, that works better, I'm open for suggestions.

 

[Sportsman762]

I am not sure if this is a wise repair.

It's not a puncture, it got hit, and cracked where a bottom "peg" attaches to the tank.

The plastic peg is a high stress area, hence why it broke from the impact. A complete failure in this area will drain the radiator very quickly. If not noticed it could lead to the engine rapidly overheating. An engine is darned expensive. I would replace the radiator as a failure could be catastrophic. I am risk adverse so I would not do this if it was my tractor.
I am pretty sure this is the same engine as in your tractor. $6968 is a darned lot of money for me when I could have avoided it for 1/10th the cost.

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[rScotty]

I have had practically zero good results with super glue type adhesives on plastics. I was able to super glue coroplast plastic sign material years ago, but it required a very specific "flaming" technique (for lack of a better term). That's not necessarily related to your nylon material though.

That's what I think as well - though I am not convinced that tank is nylon. It may be some sort of polypropylene - since that is a type of plastic popular for hot water systems. At a minimum you would want to find out exactly what type of plastic it is, and then probably look at making some reinforcement for that joint using commercial adhesives - not hardware store plastic cements.

Even if it is polypro, hot water in a house isn't nearly as hot as a a radiator has to deal with. And to make it worse, that break isn't a slip joint with lots of surface area at the break, it's a butt joint right in the wrong direction to hold pressure. To stand a chance of working for a while, It needs lots of surface area.

The trouble I have with this repair is that most of the ideas in this thread would work for a little while - good enough to finish a job or maybe a season. But when it fails you don't just lose the coolant, you could lose a diesel engine.

Bottom line is I don't see a decent radiator repair. You might want to look at aftermarket generic replacement radiators. Maybe Google replacement compact tractor radiators.

rScotty

 

[paulsharvey]

Hmm, after watching more on YouTube, I'm wondering if I should plastic weld it? Everything seems to suggest tank is Nylon, and in automotive applications, the "right" fix is to weld the crack; preheat with heat gun, about 250 degrees F, use welder to "gouge" the crack, add nylon rod, and "stir" the rod into the parent material. I have also seen some suggesting heat pressing SS screen into the repair

 

[rScotty]

Is it nylon? How do you tell? Are there different types of Nylon?

 

[paulsharvey]

Is it nylon? How do you tell? Are there different types of Nylon?

Tomorrow I'll try to cut a sample. Everything I've seen suggest the Vast majority of the tanks are Nylon 6-6 or 66, it seems like different sites refer to it different.

 

[mllud]

Make sure you rough the surface with a small burr. Texture will help the bond stick. I can't suggest a material. But I would fill that into a gusset bond. Applying JB weld thin doesn't work well.
That is a high stress point. It's almost broke off. I don't know if its thick enough to remove the nipple and tap it with NTP tap and screw in a nipple.
Even if you only had a thread or two all the way around the diameter holding it could be stronger than just filling a crack.
Then fill with epoxy or plastic weld for stiffening as suggested. I can't think of a fitting that would replace the nipple.

Whatever you do after you clamp your hose put a strain relief on your hose so its not getting pulled to the side.
Maybe a guard also.
Find a plastic welding group or maybe the RC crowd.

 

[number two]

Rapid-Fix.
Google it.
Good Luck!

 

[mllud]

I don't know if it could be PVC.

 

[5030]

Are you sure it's not molded structural structural fiber? The tanks on my Kubota's are. I'm with everyone else, just replace it. If it fails, you could very well lunch the engine.

 

[bearthebruce]

My 2 cents... the problem with nylon is that with age, the water in the material evaporates leaving a brittle material. Once it cracks and fails, it continues to crack and fail.

Learned all this the hard way with nylon parts used in our diagnostic tools. Some of our nylon parts would just break apart. We found that the region in which it used, the temps at which it used, and so on all had an effect. Nylon's flexibility and durability do change with environmental conditions.

I am with all those that say, replace. Your repair may hold for awhile but it is going to fail again. Will you be out in the field/woods when a major fail occurs? Why risk it?

 

[pmsmechanic]

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.

 

[sandman2234]

If you decide to repair it, and want to add a very fine mesh stainless steel to the epoxy, let me know and I will give you some. I had to buy a huge sheet for a project that used a 1 inch square, and I have a lot left over!
David from jax

 

[5030]

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.