JB Weld versus Loctite for grubscrews

[fafrd]

A question for those of you that have used Loctite Red for securing stainless grubscrews into these Aluminum terminals.

Did you bother to use primer?

The Loctite directions state that both stainless and aluminum are ‘inactive metals’ and so need to be primed, but I think I’ve heard from several here that primer is nut necessary.

I’ve cleaned my grubscrews and terminal threads with Acetone - do I need to use primer to get a successful Loctite bond or will the strength of the bond be fine without it?

 

[JRG]

A question for those of you that have used Loctite Red for securing stainless grubscrews into these Aluminum terminals.

Did you bother to use primer?

The Loctite directions state that both stainless and aluminum are ‘inactive metals’ and so need to be primed, but I think I’ve heard from several here that primer is nut necessary.

I’ve cleaned my grubscrews and terminal threads with Acetone - do I need to use primer to get a successful Loctite bond or will the strength of the bond be fine without it?

I used Loctite 263 which they say doesn’t need a primer. Used acetone to clean, applied the loctite, and let dry for 4 days before applying 35inlb to test. Held up to the test fine.

 

[fafrd]

I used Loctite 263 which they say doesn’t need a primer. Used acetone to clean, applied the loctite, and let dry for 4 days before applying 35inlb to test. Held up to the test fine.

Ahhh, that may be the issue - I got 271 (all the store had).

I’ll get some 263 - seems much simpler (and cheaper) to skip the primer if there is a way to get an acceptable cure without it...

Thanks.

 

[JRG]

Ahhh, that may be the issue - I got 271 (all the store had).

I’ll get some 263 - seems much simpler (and cheaper) to skip the primer if there is a way to get an acceptable cure without it...

Thanks.

To be fair, the “SS” studs that came with my Basen lishen cells don’t seem to be 100% stainless steel, they are slightly magnetic. Strangely the nuts they provided are completely non-magnetic.

 

[Hedges]

To be fair, the “SS” studs that came with my Basen lishen cells don’t seem to be 100% stainless steel, they are slightly magnetic. Strangely the nuts they provided are completely non-magnetic.

That might be for the best.

Stainless Steel Galling and Its Causes | RG Group

Being aware of galling & taking precautions when using stainless steel parts, you can avoid the hours of headache and rework. Learn more!

www.rg-group.com

"Sometimes using two different stainless steel grades will help prevent galling. By having dissimilar hardness ratings, the materials are much less likely to deform or fuse with one another.

In the worst case, the softer material will deform before damaging the other material, allowing you to remove the damaged part without affecting the other.

Even with differing materials, you should still apply anti-seize since this tip isn’t a cure-all. This is an added protection, especially suited for stainless steel hardware."

 

[fafrd]

To be fair, the “SS” studs that came with my Basen lishen cells don’t seem to be 100% stainless steel, they are slightly magnetic. Strangely the nuts they provided are completely non-magnetic.

Well, 263 explicitly states that it works with Stainless steel, so I think I’m good.

Apparently Loctite needs lack of oxygen and presence of metal molecules to cure, and the ‘inactive metals’ including stainless steel and aluminum don’t give up their surface metal molecules freely enough to result in a cure.

The ‘primer’ apparently includes some copper molecules to provide an easier source of metal molecules for the Loctite that needs it including 271.

But 263 must have some secret sauce added to allow it to get stainless to give up surface molecules of metal more easily, since it explicitly states it does not need primer to work with stainless.

263 is about double the price of 271 but once you factor in the cost of the primer, it’s cheaper.

Cheaper, easier, and proven - no-brained like that don’t come along every day...

 

[JRG]

Well, 263 explicitly states that it works with Stainless steel, so I think I’m good.

Apparently Loctite needs lack of oxygen and presence of metal molecules to cure, and the ‘inactive metals’ including stainless steel and aluminum don’t give up their surface metal molecules freely enough to result in a cure.

The ‘primer’ apparently includes some copper molecules to provide an easier source of metal molecules for the Loctite that needs it including 271.

But 263 must have some secret sauce added to allow it to get stainless to give up surface molecules of metal more easily, since it explicitly states it does not need primer to work with stainless.

263 is about double the price of 271 but once you factor in the cost of the primer, it’s cheaper.

Cheaper, easier, and proven - no-brained like that don’t come along every day...

I’d also recommend to let it dry for more than 24hrs, just to be safe, since cure rate is partially dependent on temperature.

 

[fafrd]

I’d also recommend to let it dry for more than 24hrs, just to be safe, since cure rate is partially dependent on temperature.

I can leave them a full week no problem.

I also have a temperature-controlled chamber and can maintain temps of 80F or even higher - what is the best curing temperature?

 

[JRG]

I can leave them a full week no problem.

I also have a temperature-controlled chamber and can maintain temps of 80F or even higher - what is the best curing temperature?

Not sure. I saw a loctite chart somewhere in one of their brochures.

 

[fafrd]

Not sure. I saw a loctite chart somewhere in one of their brochures.

Looks like it will cure almost instantly at 40C (104F) but 24 hours is enough for a full cure even at 5C (41F): https://tdsna.henkel.com/americas/n...95AAF2B4355B8525760E004BEA0A/$File/263-EN.pdf

At 22C (72F) you get a full cure in 6 hours, so 24 hours at our typical indoor temps of 65F should work just fine...

 

[Hedges]

It says large gaps take much longer to cure (graph shows 72 hours vs. 2 hours for partial cure 80% strength), but activator helps.

"Cure Speed vs. Activator Where cure speed is unacceptably long, or large gaps are present, applying activator to the surface will improve cure speed"

 

[fafrd]

It says large gaps take much longer to cure (graph shows 72 hours vs. 2 hours for partial cure 80% strength), but activator helps.

"Cure Speed vs. Activator Where cure speed is unacceptably long, or large gaps are present, applying activator to the surface will improve cure speed"

Well again, I can wait a full week if needed.

Or I can use my heat chamber to heat up 4-6 cells at a time to 40C / 104F (or whatever maximum temps the cells can safely take).

The only gap that will be ‘large’ is at the bottom where there may be a 1-2mm gap to the bottom of the stud + another 1-2mm indent/cone into the bottoms of the grubscrew...

ArthurEld did report Loctite Red continuing to leak out of his cells for several days after applying Loctite, so accelerating the cure by heating the cells may make sense...

 

[Darkstar]

I’m getting ready to install 20mm SS M6 grubscrews into my EVE 280Ah cells and am down to the last detail of whether to use JB Weld or Loctite to secure the threads.

So I’m asking those members who have experience with both whether there is any disadvantage to using JB Weld over Loctite that I am overlooking?

I understand JB Weld will make a permanent installation and that the grubscrews can only be be removed by stripping out the threads while Loctite makes non-destructive removal possible, but I am not interested in ever removing these grubscrews once installed.

A higher priority for me is strength of the installation especially in the presence of worn threads. The top 3 aluminum threads of my terminals are visibly worn from just 4 insertions/removals of SS bolts with light force (by hand) and one terminal is pretty much stripped over the top 3 threads from being torqued to 4Nm / 35 inch-lbs.

So I want to use these threads only once ever again and have as strong a connection as possible the the 3 pristine lower threads on the worn remains of the upper 3 threads.

I believe JB Weld will be better for an ‘as-strong-as-possible’ permanent installation but appreciate any heads-up of JB Weld is inferior to Loctite for reasons other than the one already listed (removal).

If anyone has already used JB Weld to secure M6 grubscrews into the M6 aluminum threaded holes tapped into 280 Ah LiFePO4 cells, I’m interested in any tips and especially in any regrets.

I understand the holes should be well-cleaned first, so any advice on the best way to clean the threaded holes would also be appreciated...

I have used both on grub screws/battery terminals. Loctite Red with Primer holds MUCH better than JB weld. JB weld has failed on me, loctite has remained locked tite.

 

[DerpsyDoodler]

You’ve had such rotten...luck. I hope you get this solved. I just used jb weld, coated the bottom of the threaded terminal and the bottom of the stud. Then I hand tightened in the stud/grub screw, and just snugged it a little with an Allen wrench. Let sit to cure.
of course, I made sure the threads were good before I started jbwelding anything. I had to use a m6-1 bottoming tap on many of the terminals, but not to cut whole new threads. I just had to clean up existing taps. once I did that, I was able to gently hand tighten m6 bolts and studs into the terminals.

 

[Gazoo]

Well again, I can wait a full week if needed.

Or I can use my heat chamber to heat up 4-6 cells at a time to 40C / 104F (or whatever maximum temps the cells can safely take).

The only gap that will be ‘large’ is at the bottom where there may be a 1-2mm gap to the bottom of the stud + another 1-2mm indent/cone into the bottoms of the grubscrew...

ArthurEld did report Loctite Red continuing to leak out of his cells for several days after applying Loctite, so accelerating the cure by heating the cells may make sense...

I let my 271 cure for apx. 48 hours. I did not use a primer. Any that leaked out was within the first hour. Room temp 72. There is no need to heat the cells and heat is not healthy for the cells.

 

[Gazoo]

I have used both on grub screws/battery terminals. Loctite Red with Primer holds MUCH better than JB weld. JB weld has failed on me, loctite has remained locked tite.

That surprises me since JB Weld has a higher tensile strength than Loctite. Did you use the fast cure stuff or the standard original JB Weld?

 

[fafrd]

You’ve had such rotten...luck. I hope you get this solved. I just used jb weld, coated the bottom of the threaded terminal and the bottom of the stud. Then I hand tightened in the stud/grub screw, and just snugged it a little with an Allen wrench. Let sit to cure.
of course, I made sure the threads were good before I started jbwelding anything. I had to use a m6-1 bottoming tap on many of the terminals, but not to cut whole new threads. I just had to clean up existing taps. once I did that, I was able to gently hand tighten m6 bolts and studs into the terminals.

JB weld worked well for me, but not enough to save a partially-stripped (and shallow) terminal.

I’ll find out how well I did with the Helicoil tomorrow - pretty certain it will be strong enough, but will it be straight?

For my remaining terminals, JB Weld was very slow - when I tried to do more that 1 cell / 2 terminals at a time I got into trouble.

I’m hoping Loctite Red will be much faster to finish up the remaining 9 cells...

 

[DerpsyDoodler]

That surprises me since JB Weld has a higher tensile strength than Loctite. Did you use the fast cure stuff or the standard original JB Weld?

I didnt use the fast cure stuff, and jbweld is rated much stronger than loctite. I bought jbweld thread-locker red, too. havent used it, but am considering it for the nuts on final assembly. It’s not like this stuff is meant to be dis and re assembled a dozen times. Eh, I have nylock nuts and enough stud for a second nut (just in case). Thread locker can sit in my toolbox till it’s actually needed for something.

 

[fafrd]

I didnt use the fast cure stuff, and jbweld is rated much stronger than loctite. I bought jbweld thread-locker red, too. havent used it, but am considering it for the nuts on final assembly. It’s not like this stuff is meant to be dis and re assembled a dozen times. Eh, I have nylock nuts and enough stud for a second nut (just in case). Thread locker can sit in my toolbox till it’s actually needed for something.

The main reason you want threadlocker is to prevent the threads being exercised (which causes gall, threadwear and eventually sheer).

If you are not going to lock your grubscrews, suggest you make sure to use an Allen Head wrench whenever loosening or tightening a nut...

 

[Gazoo]

havent used it, but am considering it for the nuts on final assembly. It’s not like this stuff is meant to be dis and re assembled a dozen times.

Yeah but won't using it on the nuts effect the torque readings?