J B Weld

[blackthorn]

Can cured J B Weld be drilled and tapped and if so, how strong would the threads be. I have this idea for making handles for a foot locker I am building for my great grandson and I want to make something sort of unique. I want to try using different brass casings held together with J B Weld.

[oldred]

I have been using JB weld just about forever it seems and I love the stuff, it's a real problem solver when used within it's limits. What I consider it's limits for drilling and tapping would be to consider it as if it were soft wood. I know it's a heck of a lot harder than even a hard wood but still it's tensile strength is quite low compared to even some plastics, mix up a batch and give it at least 48 hrs (longer is better) then drill/tap and torque a bolt in the hole to the stripping point and you will see what I mean.



Don't be tempted by the "JB Quick" because while it initially "sets" a LOT faster it still takes just about as long (48 hrs or so) to reach it's max strength and then it's not quite as strong as the regular JB.

[bangerjim]

I have used JB for years. Tap it, drill it, machine it, turn it on the lathe.....just like metal. Just like oldred above.......do NOT use the quick junk! It is great for quick fixes on non-load-bearing stuff, but for real metal-like strength, use the long set standard stuff.

I call it a miracle in tubes. Just make sure you surface is roughed up a bit and perfectly clean!!!!!!!!

But is will break! Do some test set-ups to test the strength you need.

banger

[pdawg_shooter]

Plastic steel has more strength for drilling or tapping.

[blackthorn]

Thank you.

[WallyM3]

Plastic steel has more strength for drilling or tapping.

Epoxy or putty best?

[Alstep]

Gray Marine-Tex is another good product. I've used it to bed rifles, patched cracked castings, sealed holes in gas tanks. Drills & taps nicely. It is strong up to a point, but like everything else, has it's limitations.

[Trey45]

It can be drilled and tapped, but in my honest opinion you should use a helicoil instead. Drill, tap for the helicoil, use JB weld on the helicoil insert and allow it to harden.

[popper]

original JB is plastic with granite embedded. Try the helicoil or plastic steel for more strength. Made in east texas.
Devcon stuff is really good and very machinable.

[kootne]

Just glue in a nut with the desired thread in it.
kootne

[seaboltm]

You could mix some atomized steel in the JB weld (or other epoxy). I do this sometimes when doing a fix. It actually throws sparks when grinding it!

[oldred]

You could mix some atomized steel in the JB weld (or other epoxy). I do this sometimes when doing a fix. It actually throws sparks when grinding it!

JB Weld already has an optimal amount of steel mixed with it (a magnet will actually stick to it because of this) as it comes from the tube, adding more will weaken it.

[Boyscout]

I glued a broken toliet bowl flange with it 15 years ago and it is still holding.

[oldred]

I glued a broken toliet bowl flange with it 15 years ago and it is still holding.


I know of a guy who repaired a burned piston in a Ford 8N tractor engine with the stuff! He scuffed the area where the cast iron piston was burned down the side then applied the JB Weld followed by re-cutting the ring groves with a hack saw blade, not exactly a high tech repair but the darn thing was still running over a year later! It in fact was not an original idea and he did it because he had heard of someone else doing the same thing successfully.


Not even suggesting this is a good idea, just repeating what was done.

[phonejack]

This is one heavy duty application I have used JB weld for. Back in the eighties, I bought a basket case '48 flat head Harley. The exhaust pipes were a press fit, not bolt on , into the iron cylinder head. On one of the head ports,part of it was broken off. I greased the exhaust pipe and put it into the head and used 3 or 4 tubes of JB weld to build up around the pipe. Let it cure for a few days and fired it up. Had the bike for twenty more years years and it never came loose. Great stuff.

[oldred]

Not surprised about the Harley as I have seen this stuff take incredible levels of heat, far in excess of what a person could reasonably expect from an epoxy.

[seaboltm]

JB Weld already has an optimal amount of steel mixed with it (a magnet will actually stick to it because of this) as it comes from the tube, adding more will weaken it.

Learn something new everyday! I keep atomized steel on hand for steel bedding actions with acraglas.

[MaryB]

Friend of mine cracked the engine block on his riding lawn mower. His lawn is 10 acres so a rider is a must. He took the engine off, drained the oil, degreased everything well and then used JB weld on it. Lasted 2 more years before he finally ordered a new engine.

[DoubleAdobe]

It can be drilled and tapped, but in my honest opinion you should use a helicoil instead. Drill, tap for the helicoil, use JB weld on the helicoil insert and allow it to harden.
Real good advice. Take that to the bank.
To reiterate, JB Weld is a superior product with mystical properties when used with a realistic scenario in mind. It is not magic, you still have to use due diligence and give it time. But it is damned amazing for what it is. Be patient with the prep and times.

[jakec]

whats "plastic steel"? is that just a name brand of epoxy?

[pdawg_shooter]

It is a product made and sold by Devcon. I buy it locally at a place that sells bearings. It was developed to build up worn shafts and such. Knowing Amazon you can most likely buy it there. I also used it to bed rifle actions. Way stronger than any epoxy.

[lead-1]

A place I used to work at used a stuff called PC-7, it was an epoxy putty in two parts. I mixed up a batch and repaired an intake on a small block chevy engine for the thermostat housing to bolt to. Filled in the broken spot and let it cure completely, drilled and tapped for the bolt and it is holding still. That was roughly 12 years ago.

[Trey45]

I've used PC-7! There's a marine grade called PC-11. Both are miracle workers.

[DoubleAdobe]

I've used PC-7! There's a marine grade called PC-11. Both are miracle workers.
Both mentioned are good products within their abilities. Both are good to go in the automotive or gun spectrum, IMHO>

[trapper9260]

I worked in a welding shop of repairs and I see some bring something to be fix and they used JB Weld and it broke and for a 5 min. job turn to a 30 min job because need to grind all the JB Weld out before I was to braze it back up.it is a pain when jobs like that came in.You have cast steel and then cast iron and some can not tell and think to just use JB Weld and think that is it . Like was stated it have its place. But need to see where it will work the best.

[oldred]

I worked in a welding shop of repairs and I see some bring something to be fix and they used JB Weld and it broke and for a 5 min. job turn to a 30 min job because need to grind all the JB Weld out before I was to braze it back up.it is a pain when jobs like that came in.You have cast steel and then cast iron and some can not tell and think to just use JB Weld and think that is it . Like was stated it have its place. But need to see where it will work the best.


Despite the name JB Weld should NEVER be used as a substitute for a weld for broken steel or iron if there is any load required! The tensile strength is only a small fraction of the strength of grey iron let alone steel, hey this stuff may be pretty good for some things but in the end it's still glue!