JB Weld not curing properly? (2024)

Attached a Aeropac retainer to the HMAS Bonestell Saturday. Squirted out the portions of JB Weld, mixed it up, spread it around the aft of the motor tube and slid the retainer in place. There was a little bit of a bead around the base of the retainer so I smoothed it out into a fillet as best I could. JB cures quickly.
Yesterday I was looking over the attachment and noticed some JB smeared on the outside of the Aeropac. Crud, this stuff is supposed to be rockhard and nearly impervious. In agitation I picked at it with a fingernail and it scraped off!
Quite easily in fact. Concerned I checked the mixing cup and the JB left in the cup is still cured but soft, a wee bit tacky and pliable. A a rubber like texture.
I've torqued on the retainer as best I could and it doesn't budge, but what happens when it heats up?
This is my first experience with JB Weld and it was purchased last week, so it isn't an older batch.

Wazzzup whit dat"????

I don't know where you got the idea that "JB cures quickly" because in my experience, it does not. It stays soft for a few hours.

That said, insufficient curing could be caused by several factors, the most important of which is:

MIX REALLY REALLY THOROUGHLY. Scrape the surface of the mixing stick, and the container/surface you're mixing on, and then scrape them again. And then mix. And then repeat.

CarVac said:

I don't know where you got the idea that "JB cures quickly" because in my experience, it does not. It stays soft for a few hours.

That said, insufficient curing could be caused by several factors, the most important of which is:

MIX REALLY REALLY THOROUGHLY. Scrape the surface of the mixing stick, and the container/surface you're mixing on, and then scrape them again. And then mix. And then repeat.

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Let me clarify, it sets quickly.
The package states "Sets in 6 minutes, cures in 4-6 hours" but that was 48 hours ago. SHould I be concerned about the joint strength?

CarVac said:

I don't know where you got the idea that "JB cures quickly" because in my experience, it does not. It stays soft for a few hours.

That said, insufficient curing could be caused by several factors, the most important of which is:

MIX REALLY REALLY THOROUGHLY. Scrape the surface of the mixing stick, and the container/surface you're mixing on, and then scrape them again. And then mix. And then repeat.

Click to expand...

I agree ,mix,mix and when you think you are done....mix some more.

Also ,you should apply some JB inside the Aeropack retainer itself ,and not just the motor tube ,as you may squeeze all the epoxy out if it`s only on the MT.

JB Weld (not the quick set stuff) should stay workable for a good hour +

Paul t

Pem Tech said:

Let me clarify, it sets quickly.
The package states "Sets in 6 minutes, cures in 4-6 hours" but that was 48 hours ago. SHould I be concerned about the joint strength?

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Is this JB Qwik (or however it's spelled)?

JB Qwik is not sufficiently temperature resistant for motor retention.

In fact, from the one time I used it, it never hardened. I consider it pretty much worthless.

CarVac said:

Is this JB Qwik (or however it's spelled)?

JB Qwik is not sufficiently temperature resistant for motor retention.

In fact, from the one time I used it, it never hardened. I consider it pretty much worthless.

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Foul language....
It is Kwik Weld....

%^($#! how am I going to get the retainer off to reattach?

Pem Tech said:

Foul language....
It is Kwik Weld....

%^($#! how am I going to get the retainer off to reattach?

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Try a hairdryer. Heat it up, which will further soften the epoxy, and then grab the retainer body with something insulating and yank it off.

CarVac said:

Try a hairdryer. Heat it up, which will further soften the epoxy, and then grab the retainer body with something insulating and yank it off.

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I'll borrow one from one of the grrls at work and give it a shot.

Glad I asked and didn't just fly her as is.

Pem Tech said:

I'll borrow one from one of the grrls at work and give it a shot.

Glad I asked and didn't just fly her as is.

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Got a mini propane torch? Just wave it around the metal, trying not to set the rest of your rocket on fire... On second thought, with the luck your having lately, just stick with the hair dryer :tongue:

Adrian

jd2cylman said:

Got a mini propane torch? Just wave it around the metal, trying not to set the rest of your rocket on fire... On second thought, with the luck your having lately, just stick with the hair dryer :tongue:

Adrian

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Sadly enough, you have a point. I do have a propane torch that could be turned down...
If it all goes to h*ll you get custody of the Llamas.

Pem Tech said:

I'll borrow one from one of the grrls at work and give it a shot.

Glad I asked and didn't just fly her as is.

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Um, Layne?

You're likely going to make a mess of that hairdryer.

Unless you'd rather one of the women never speak to you again, go to the store and spend $10 on your own hair dryer....

-Kevin

better yet, get a real heat gun.

troj said:

Um, Layne?

You're likely going to make a mess of that hairdryer.

Unless you'd rather one of the women never speak to you again, go to the store and spend $10 on your own hair dryer....

-Kevin

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troj said:

Um, Layne?
You're likely going to make a mess of that hairdryer.
Unless you'd rather one of the women never speak to you again, go to the store and spend $10 on your own hair dryer....
-Kevin

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Not sure what you think I'll be doing with said heating device, but in one particular case that outcome would be welcome.

SwingWing said:

better yet, get a real heat gun.

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OH BOY!!
And excuse to buy another tool!!!

https://www.harborfreight.com/1500-watt-dual-temperature-heat-gun-572-1112-96289.html

qquake2k said:

https://www.harborfreight.com/1500-watt-dual-temperature-heat-gun-572-1112-96289.html

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Low prices and ever improving quality keep me going back to HF. Having things on sale that allow you to add in the 20% off coupon is

nice. Thinking over a few more tools this month ...like an electric chainsaw...

Oh, yeah, HF has their own version of JB Weld and it's the slow harden variety. Worked good for the things I've used it for.

Pem Tech said:

Not sure what you think I'll be doing with said heating device, but in one particular case that outcome would be welcome.

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Trust me, if your hide is at risk, you'll get something stuck to it....

OH BOY!!
And excuse to buy another tool!!!

Click to expand...

Now you're thinkin'!

-Kevin

dave carver said:

Low prices and ever improving quality keep me going back to HF. Having things on sale that allow you to add in the 20% off coupon is

really

nice. Thinking over a few more tools this month ...like an electric chainsaw...

Oh, yeah, HF has their own version of JB Weld and it's the slow harden variety. Worked good for the things I've used it for.

Click to expand...

I buy a lot of tools from Harbor Freight. I've rarely been disappointed.

qquake2k said:

https://www.harborfreight.com/1500-watt-dual-temperature-heat-gun-572-1112-96289.html

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WOW! They are cheap.....

Area66 said:

No, he have to invite the girl to come to help him, he need someone to hold the dryer .....

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I don't think their husbands would approve.

Pem Tech said:

WOW! They are cheap.....

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Yeah, and a heat gun will get hotter than a blow dryer, and direct the heat to a smaller area.

This has got me thinking. I really want to add rail-buttons (with stand-offs) to my Ventris, but since I've already installed the MMT and the retainer, I cant get the well nut in place for the lower button. If I could get the estes retainer off, I could make it work. Would a heat gun soften jb weld (the standard stuff, not quickweld) enough to pull the retainer? Also, would the retainer survive, or would I be replacing it?

(Sorry about hijacking his thread, Layne.)

Pem Tech said:

I don't think their husbands would approve.

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That, and you'd likely end up with too much hot air!

rbelknap said:

This has got me thinking. I really want to add rail-buttons (with stand-offs) to my Ventris, but since I've already installed the MMT and the retainer, I cant get the well nut in place for the lower button. If I could get the estes retainer off, I could make it work. Would a heat gun soften jb weld (the standard stuff, not quickweld) enough to pull the retainer? Also, would the retainer survive, or would I be replacing it?

(Sorry about hijacking his thread, Layne.)

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It does, but you'll turn your Estes retainer into a puddle too.

I recommend getting Acme standoff rail guides which may be tall enough for your purposes, and can be surface-mounted without a problem.

rbelknap said:

This has got me thinking. I really want to add rail-buttons (with stand-offs) to my Ventris, but since I've already installed the MMT and the retainer, I cant get the well nut in place for the lower button. If I could get the estes retainer off, I could make it work. Would a heat gun soften jb weld (the standard stuff, not quickweld) enough to pull the retainer? Also, would the retainer survive, or would I be replacing it?

(Sorry about hijacking his thread, Layne.)

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I'm not sure I understand, Robert. Are you saying there's not enough room between the lower body tube and motor tube for a well nut? What is the diameter of the lower body tube? And Dog House has rail button standoffs.

https://doghouse.blastzone.org/DogHouseRocketry/Rail_Buttons.html

rbelknap said:

This has got me thinking. I really want to add rail-buttons (with stand-offs) to my Ventris, but since I've already installed the MMT and the retainer, I cant get the well nut in place for the lower button. If I could get the estes retainer off, I could make it work. Would a heat gun soften jb weld (the standard stuff, not quickweld) enough to pull the retainer? Also, would the retainer survive, or would I be replacing it?

(Sorry about hijacking his thread, Layne.)

Click to expand...

Bad Breath to the Thread Hijacker!!!
Wait, too late for that....

qquake2k said:

I'm not sure I understand, Robert. Are you saying there's not enough room between the lower body tube and motor tube for a well nut? What is the diameter of the lower body tube? And Dog House has rail button standoffs.

https://doghouse.blastzone.org/DogHouseRocketry/Rail_Buttons.html

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I've got about 1/4" between the BT and the MMT

I have stand-offs, and there is enough room for a weld nut between the BT and MMT. There isn't enough room the get the shank of weld nut past the base of the retainer (by the width of the retainer threads. Argh.)

I could cut a slit in the body tube, and then patch it back up, or I could try filing down the weld nut, but I might mess up the threads.

The well nuts that I have, I wouldn't be able to insert them all the way before they'd but up against the MMT. I know this isn't too big of a deal, since they are designed to contract, but then the 1" long screws I have would be pressing into the MMT. 3/4" long screws are just short enough that I can't engage the threads in the well nut.