How do you make JB Weld NOT stick?

I'm going to use JB Weld to repair a piston in a cylinder. What can I do to get the JB to stick to the piston, but not to the cylinder? As far as I've heard, it'll adhere to anything. Thanks.

-Jeff

 

In my experience, JB Weld does not like heat at all...

 

JB weld on a piston????? Do they make a new one I don't know about?

 

That's been my experience too...Is the piston forged or cast? Could it be welded onto, and then ground back to shape with a dremmel tool? Just a thought.....

 

I don't want to take the motor apart. I'm lazy. It's already broke, so if it doesn't work, I'm not out anything. It's a low compression flathead to boot. I know people that have used it on cracked cylinders and cracked heads with no problem, so why not a slightly burned piston? It's only got to run for a few months anyway till I swap in the Hemi I'm collecting parts for.

 

Is it a chip or a crack? Or is there a whole chunk missing? From what area of the piston?

 

It's a burned spot on the edge of the piston right next to the cylinder wall, about a 1/4" wide. It's melted down into the ring land, so I have compression leaking. I thought it was just a burned valve 'till I pulled the head off. I was using cheap gas when I shouldn't have been, because it went while going down the highway. Still ran good, but misses on the burned cylinder, so I neew a temporary fix until after BTT50's. I'll probably put less than 1,000 miles on it in that time.

-Jeff

 

**** it try it and let us know how it went!!!!!!!!

 

JB Weld is rated to 600 degrees F.

Combustion chamber temps are ... what? 1400 - 2000 F.?
Granted, not a steady state temp, but I'm sure the JB rating would be exceeded.

 

I don't know what to tell you man...I guess if it was me, I'd drop the pan, take the rod bolts offa that one piston and push it out through the top....gotta buddy up here in Fondy that could add some weld to that edge and then you could just work it back down with a belt sander and put it back together with the old con rod bearings...figure it like this...you've got it apart this far, and you're gonna hafta replace the head gaskets, so if it doesn't work, you're gonna be out the dough for those and the time you had in taking it apart and putting it back together....just makes sense to me to go a little further with it and know for sure that it's gonna hold instead of gamblin'....

 

I might even know someone that's got an extra piston laying around...what year flatty is it? Ford?...

 

in my experience JB Weld won't take much more heat than your average piece of toast.

I don't think it'll work on a piston- I've never seen it work at all. I just hope the chunk that falls out of your piston ends up in the oil pan and not blocking some vital clearance, oil gallery, oil pump, etc.

there's lots of manufacturers of JB Weld-like compounds, and their products are MUCH higher quality.

overall, I hate the stuff; I always end up s****ing, grinding or burning it off and doing it right, like I should have the first time.

 

Slide a piece of wax paper down the bore, won't stick then, trim the excess with a razor blade. Can't do any more damage than the J-B...............OLDBEET

 

You tripping?

 

let's start a pool,

I say it'll **** the bed in under fifteen seconds, seizing the piston in the cylinder and rendering the crank and block useless.

Paul

 

it only works like that IN FLORIDA..
they are partial to MONKEY fixing **** like that

 

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I say it'll **** the bed in under fifteen seconds, seizing the piston in the cylinder and rendering the crank and block useless.

Paul



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5 seconds max. upon startup the JB leaves the piston and wedges between the exhaust valve and seat, causing it to run worse than it did with the burnt piston

 

make a coffee table out of the flatty-Install the Hemi now-YOU NEED A HEMI.

 

I used JB weld on a set of steel chevy valve covered, to fill in some spot welds I cut off. It lasted for about 4 months before it started to try to peal off. It really doesn't like heating up and cooling down on something with some thermal expansion to it.

 

I've got another hair-brained idea. You can't weld aluminum to steel, so it shouldn't stick to the cylinder wall. You can see where I'm going with this... If that idea doesn't work, I'll try this one. Either way, I'll keep you posted.

-Jeff the Crazy *******.

 

How's it turnin out Bugman?

 

I JB welded a bung to my exhaust pipe on my 93 Chevy so I could put in a new 02 sensor, the old one stripped out with the old sensor. I cleaned the **** outta the pipe with sandpaper and put it in place, then let it "dry" or "cure" or whatever it does. Then, after a day or so, my son and I took the truck to the store. On the way there's a pretty good size hill we had to go up, like 2nd gear for a while so the engine heated up real good size, and when we got to the top we hit a red light. There was some poor ****er in a Caravan with his wife next to us... and for the rest of my life I will never forget him screaming "oh my God what is that smell? Holy ****, what is that AWFUL SMELL? I'm gonna puke! NO, I'M GONNA DIE!" By then the light turned green and I left... But to this day I wonder...

So anyway, unless you can deal with the most putrid, horrible, plastic, carcinogen burning smell you ever dealt with, never put that **** anywhere where there's gonna be any sorta heat involved!!!

Jay