JB Weld.... love it or hate it?

JB Weld is one of the best products evah …evah … evah …

I use it for all kinds of things. If that doesn’t fix the problem, it’s time to start over.

@meanjoe75fan, I also deleted the air injection on that '90 Toyota of mine. But, my air pump broke on me and the replacemet cost was outrageous. I also passed emissions for several years afterwards with low numbers. As long as you keep it tuned, the air injection is not needed.

My dad used to use JB Weld and had great success with it. I tried it once and was not thrilled with the results so I never used it again.

@BustedKnuckles It’s nice to not have emissions testing.

@missileman If at first you don’t succeed…

I always consider it an option. probably too often. I haven’t had a bad failure out of it in a while though. I’m due for one.

I have used it for decades on almost everything. Filled and rebored throttle body shaft bushings, drilled and tapped mounting bolts for light duty stuff, glued together innumerable broken toys but I guess my most outrageous “repair” was an old snow blower engine that threw a rod. It was more of a “let’s see what happens” kind of experiment but I made new bushings for the rod and glued it back together w/JB Weld. I also glued a patch on the crankcase. It ran like that for years afterward until I tossed it out for other reasons.

BTW- a better product for sealing gas tanks is Seal All in my opinion and experience.

@TwinTurbo, I never thought about tapping it. It sounds good though.

I had a cheap poulan 18" chainsaw a few years back. It may have been my fault for over tightening, but I cracked the plastic housing that held the bar studs. I dobbed a huge pile of JB on it and let it sit for about a week. I slapped it back together and everything worked great for about an hour. Then the crank shaft literally broke off clean behind the clutch. It was a completely an unrelated issue I think, but it was definitely a done deal. I buy no more poulan.

I guess I’ll never know if the JB Weld would have fixed it permanently.

Why “love it or hate it”, why not anything in between? I have fixed a lot of stuff over the years with it. It almost feels like you’re cheating somehow when using it because you can pull off miracle fixes of stupidly broken stuff without breaking a sweat, and the fixes are permanent within reason. Probably the most iffy fix I ever used it for was a leaking hot water pipe in a really inaccessible location.

Just wondering…has anyone ever tried JB Weld for an exhaust repair? I have some JB Weld Steel Stik that says it can handle temps up to 300 F. I remember the old muffler repair kits that had some kind of epoxy compound.

@jesmed1 , I just this morning applied so JB Weld Steel Stik to a busted weld on my muffler. I’m trying to get a little more time out of it to shop for the right replacement. The muffler and pipe look very good, only a little surface rust. The pipe just applied a bit too much stress on the joint thanks to a broken rubber hanger. I’ll let you know if it survives the week. This is on my daily driver.

^ Thanks for the report, will be interesting to find out how long it survives.

Here’s a related question. JB Weld is just some kind of epoxy-resin based product, right? Has anybody compared it to generic epoxy resins? You can buy a pair of small tubes of epoxy resin (the 5 minute quick-set kind) at Harbor Freight for a couple of bucks I think. I wonder if there’s any difference in performance between that and JB Quick?

That’s interesting

most of the other epoxies I see are meant to be used as glue, while JB Weld seems to be meant to be used to build up material that has rusted away, broken off, etc.

JB Weld can be sanded down, drilled, tapped, etc. after it’s had time to harden

Can the same be said of the other epoxies?

@GeorgeSanJose , not all epoxy resins are equal. JB Weld seems to have a lot of metallic properties and sets up very hard. I just used another one recently to fill some voids that is more plastic in composition. Great adhesion, but not very hard. I could easily trim excess with a pocket knife. And I’ve used another type that remained flexible once cured.

Yes, generic 5 minute epoxy at least is similar to a plastic and can be sanded. I’ve made plastic parts with it sometimes.

I split a thumbnail pretty badly at work one day.
Tried a band-aid but it really got in the way.
So I smeared a layer of JB Weld over it and it protected the nail for several days before it started crumbling away.
After that I (currently) keep it coated with clear nail polish so the crack doesn’t increase as it grows out.
Now after ~ a month the split is almost gone.
However, the nail polish does look a lot better than JB Weld

I just broke a tooth. Is JB Weld toxic? :slight_smile:

For years I had a cracked tooth

Very visible, and a front tooth, at that!

Anyways, when I finally got a good dental plan through my current job, I decided to get it fixed

The dentist ground the jagged edge down with some kind of a die grinder/dremel type of tool. Then they mixed up some kind of epoxy, kneaded it into the correct shape, and cured it with a type of heat lamp

It looks very natural, not gray like JB Weld . . . !


Some of those dental mixtures set up not with heat, but with bright light; and light only of a particular color. They use a pencil shaped wand that shines a bright and directed light at the tooth. That technology could come in handy in cars too, say if you needed something to be workable while you arranged the parts in alignment, then once you got it the way you wanted, use the light wand to set it up fast. But I’ve never seen those products offered for cars or home use yet. Dentists actually use a lot of materials, technique,s and tools that could come in handy to the diy’er.

My dentist uses a wand that emits ultraviolet light.
It has a yellow colored shield that blocks the UV from shining back on the user.