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How strong is JB-Weld?


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I have used the JB weld and was very happy with the product. I put 2 equal amounts on a Post-it-note, then THOROUGHLY mix with a toothpick, then depending on the application, I use another toothpick or a round toothpick for delicate edges. Give it the appropriate amount of time to harden, and you should be good to go. Seems to make a very strong bond...I really like it.

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Thanks Wayne!

I suppose the regular JB-Weld is stronger than the JB KwikWeld which is sort of a 6 minute JB-Weld.

I'm gluing a small brass with nickel coating, nut, to styrene so I can attach a part with a screw.

I mentioned in another thread that I used Devcon 5 Minute Epoxy and the nut didn't hold.

Edited by crowe-t
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Just an FYI...the longer ANY epoxy product takes to cure, the stronger the bond will be.

Regular JB is stronger than 5-minute stuff.

30-minute hobby-shop RC epoxy is stronger than the 15 minute stuff.

And the stuff I use (made for real aircraft) takes 24 hours to cure at room temperature, plus another 16 hours at elevated temps. Stronger than anything a modeler or layman is likely to EVER encounter. But that's why they glue airplanes together with it. B)

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JB Weld is capable of being drilled and tapped, I've never had a failure using it. I've used it to repair no structural engine block stuff like holes in the block or oil pan. Devon is another metalizer epoxy product that works well, it should for the price!

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Geez, I wish I had read this before this past weekend when I bought the J-B quick. Oh well. As for Devcon, my brother-in-law used it many moons ago to fix a cracked block on a 390 Ford. He bought the motor not knowing it had a crack under the intake manifold. It ran for at least 3 years with no leaks.

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I used Devcon for quite a while, but heard good things about JB, so Ithought I'd try it out. When I moved about 4 years ago, I packed things carefully and the only cars that dropped bumpers etc, were models from long ago that were assembled using tube glue. The rest can be moved around with no problem. So for final assembly, I ALWAYS use JB.

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The primary place where JB or any adhesive, no matter how "strong" it's supposed to be, really lets people down is when it's used for small-surface-area butt joints. If you glue two pieces of 1/16" stock together end to end and expect it to hold...you're dreaming. Even my insanely strong and expensive aircraft stuff wouldn't last long in that application.

The smaller the surface area of your joint, the more likely it will fail, period. It's just common sense.

Yes, you can probably glue tiny little nuts to a model with JB and screw something into them, but as mentioned by someone above, if the screw bottoms in the hole, it will simply jack the nut right off the part it's glued to. And if the threads of the nut aren't perfectly clear, it will probably twist off as you try to screw a screw into it.

One other thing to remember when using JB or similar "hardware store grade" epoxy products: although they're made to be somewhat tolerant of mixing proportion errors, take the time to try to get EXACTLY a 1:1 ratio (if that's what is called for). Epoxies really like to be mixed in the correct proportions to get maximum strength. It's important to give all the little molecules the right number of hands to hold on other molecules...really. TRY to get it as close as you possibly can to the recommended mix-ratio to avoid disappointment.

The stuff we use on aircraft HAS to be mixed on a gram scale, and it HAS to be dead-nuts on to within 1/2 of 1 %.

Edited by Ace-Garageguy
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