Plastic repair

[Mastiff]

This thread is a followup on my non-K5 problem, but I wanted to get a wider audience.

https://ck5.com/forums/threads/who-understands-obd2-evap-system.331347/

Jeep has a cracked nipple on top of the gas tank, causing a check engine light related to the evap system. I wouldn't care, but I need to pass emissions. I got under there, and luckily I can see the crack easily with the tank in place:

So I'm considering my options for some sort of plastic weld goop or something to fix it in place. I bought some JB weld plastic weld putty, which would be easy to push into the crack and wrap around the whole nipple, but is it as good as the two part? Anyone know if this particular type of plastic will bond with the JB weld? Any other options?

By the way, anyone know how to disconnect those kinds of connectors?

 

[Fastereddie]

You have to lift out that gray lock piece.
Then squeeze.

 

[Blue85]

For plastic repair, there's nothing as good as knowing what kind it is so you can pick the appropriate solvent. Likewise for plastic welding. But as a last resort you could use a plastic repair product that is supposed to be OK for many types of plastic.

 

[Mastiff]

I went with JB Weld "Plastic Bonder", since it specifically said it could do polyethylene, where many others said they could not. I don't know if that's what the tank is, but I think there's a good chance it's in that family. I tested it on the tip from an RTV tube, which is a slick resistant seeming plastic, and it at least seemed to stick well to that. The JB Weld putty did not stick (and it specifically said it did not work on polyethylene).

 

[dyeager535]

I have no idea what the proper applications are for it, but what about model glue...isn't it cyanoacrylate/CA?

Hard not knowing what type of plastic it is, many have different adhesive requirements. CA seems to be used on plastic that is pretty rigid.

Friend had her Chevy Cruze spring a huge leak this weekend. The *plastic* thermostat housing cracked.

 

[diesel4me]

Many newer vehicles use plastic thermostat housings,heater hose fittings,and other things plastic should never have been used for,like intake manifolds...it gets brittle as glass after a few years and it cracks..
I recall a Dodge in my friends shop that had a 2.7 V6 (Charger or Chrysler Cirrus ?) that had a plastic one,and the bolts broke off in the engine thanks to it having brass inserts in the thermostat housing--combined that with steel bolts and an aluminum engine,the bolts were whittled away to 1/8" due to electrolosis...turned into a real bitch of a job,half the engine had to be taken apart to extract the remainder of the bolts..

Dorman has a pretty wide selection of replacement ones,unfortunately unlike the good old days when you could swap your junk die cast "water outlet" for a cast iron one,your stuck with crap-tastic plastic..