JB Weld versus Loctite for grubscrews

[Hedges]

So I think you are saying you would only apply JB Weld to the male thread (without a vent hole)?

Yes.
Vent hole could be good, ensures air escapes. But should work without.

If JB Weld was on female thread, would push to the bottom and cause hydraulic lock.

On male thread, only a little would enter female and would probably bond stud to it.
Most epoxy would stop at the beginning of non-stripped female thread, so would back up and fill stripped area.
Trapped air might just compress (to about 100 psi) or might form a channel through epoxy in stripped area and escape. Probably would leave most epoxy bonding stud threads to stripped surface, easiest to follow air that already escaped. There would be some size bubble formed through the epoxy.

If you had a brake bleeder, could put a cup over the stud placed in hole but not threaded, and draw vacuum. However, that may suck in epoxy, leaving the hydraulic lock issue. Maybe if thread barely started, after drawing out air the 15 psi backfilling wouldn't move epoxy in very fast.
Hmm, this could also be a way to draw epoxy into a (top stripped) hole. Similar to windshield "star" repair.
All depends on viscosity. If you're unlucky, you get only the resin and not the filler.

 

[fafrd]

There are two conversations intertwingled in this thread.
1) What to do if you have damaged or stripped threads.
2) What to do if you have brand spanking new cells with good threads.

I agree with you that loctite on good threads the very first time you screw in the posts is the right thing to do. Get them in and never take them out. (I would probably use red though). In the past I used a conductive silver epoxy but have since decided it is not worth it.

Unfortunately, as DIYers, as soon as we get the cells we want to play with them...and we do. Unless someone has heard the warning that the SS screws will damage the soft aluminum threads, they end up with damaged or stripped threads. That is exactly what happened to me with the first cells I bought. A lot of others on this thread and other threads have said the same. I am willing to bet that for every one that admits they did it there are several that have not admitted it.

Exactly. So I’d say it’s actually four conversations:

1/ What to do with pristine / new threads (if such a thing even exists - I didn’t think to inspect before playing with mine). The consensus seems to be that Loctite Red is best for this situation.

2/ What to do with worn threads (some galling has resulted in visible wear on the upper threads but no actual stripped threads). This is my exact situation and Loctite Red is probably the solution of choice here as well, but until we know more about how JB Weld behaves on the presence of threads and whether it is far more troublesome to work, I’m still on the fence.

3/ What to do with partially-stripped threads (upper threads stripped but lower threads still pristine/unused and upper threads still visible even though stripped). This is what I’m facing with my one partially-stripped threads - 3 upper threads stripped out at 40 inch-lbs but still visible and lower 2 threads are pristine / unused. JB Weld will probably be stronger for this situation is it can used without entailing unnatural acts (among which I would include drilling a vent hole through the center of a stud).

4/ What to do with a completely-stripped thread (smooth walls to the bottom of the terminal hole). JB Welf appears to be proven for this case. It will ooze out the space between the male threads and the smooth walls of the hole and cleaning up the excess that emerges at the top seems to be no big deal.

I just got back from Home Depot with some JB Weld, a 1/4” bolt, and a 1/4” threaded female fitting. I’m going to glue the fitting up so it forms a sealed hole, let it cure completely, and then try glueing the 1/4” bolt into it with JB Weld. Will report back when I have any results to share...

 

[Gazoo]

I'm just amazed at this conversation -- stud strength -- if the JB Weld will hold --- we are talking about 35 inch lbs -- literally nothing as far as torque goes --- personally I would be putting blue loctite on good threads

I was going to use blue and even ordered it. After some research and reading other posts on this forum I decided to use Red. You want to do everything you can to keep the stud in place permanently.

 

[fafrd]

Yes.
Vent hole could be good, ensures air escapes. But should work without.

If JB Weld was on female thread, would push to the bottom and cause hydraulic lock.

On male thread, only a little would enter female and would probably bond stud to it.
Most epoxy would stop at the beginning of non-stripped female thread, so would back up and fill stripped area.
Trapped air might just compress (to about 100 psi) or might form a channel through epoxy in stripped area and escape. Probably would leave most epoxy bonding stud threads to stripped surface, easiest to follow air that already escaped. There would be some size bubble formed through the epoxy.

If you had a brake bleeder, could put a cup over the stud placed in hole but not threaded, and draw vacuum. However, that may suck in epoxy, leaving the hydraulic lock issue. Maybe if thread barely started, after drawing out air the 15 psi backfilling wouldn't move epoxy in very fast.
Hmm, this could also be a way to draw epoxy into a (top stripped) hole. Similar to windshield "star" repair.
All depends on viscosity. If you're unlucky, you get only the resin and not the filler.

This certainly gives a lot to think about.

I’m going to try an alternative approach with my dry run which is 180-degrees the opposite. I’m going to fry to get a small dab of JB weld in the very bottom of the hole, leaving the threads clean.

I will pre-measure the 100% thread insertion and then will thread the bolt after the JB Weld is in place in the bottom of the hole.

Air will easily be able to escape until the bottom of the bolt hits the top of the epoxy dab at which point epoxy will start to squeeze into remaining airspace and I will discover how easily it can be squeezed through the thread gap.

I’ll have the bolt head at one end and a JB Welded-on nut below the bottom end, so I’ll be able to apply some torque and see what torque is needed to get the JB Weld to ooze out through the thread gap (if possible).

If the nut stops before full insertion and even 35 inch-pounds is insufficient to get the JV Weld to ooze into the thread gap, the ‘bottom-up’ approach is a dead-end and it’s either JB Weld in a ‘top-down’ approach as you’ve described or Loctite Red which has no problem flowing through the thread gap (even wicking up into the thread gap, apparently).

 

[noenegdod]

This certainly gives a lot to think about.

I’m going to try an alternative approach with my dry run which is 180-degrees the opposite. I’m going to fry to get a small dab of JB weld in the very bottom of the hole, leaving the threads clean.

I will pre-measure the 100% thread insertion and then will thread the bolt after the JB Weld is in place in the bottom of the hole.

Air will easily be able to escape until the bottom of the bolt hits the top of the epoxy dab at which point epoxy will start to squeeze into remaining airspace and I will discover how easily it can be squeezed through the thread gap.

I’ll have the bolt head at one end and a JB Welded-on nut below the bottom end, so I’ll be able to apply some torque and see what torque is needed to get the JB Weld to ooze out through the thread gap (if possible).

If the nut stops before full insertion and even 35 inch-pounds is insufficient to get the JV Weld to ooze into the thread gap, the ‘bottom-up’ approach is a dead-end and it’s either JB Weld in a ‘top-down’ approach as you’ve described or Loctite Red which has no problem flowing through the thread gap (even wicking up into the thread gap, apparently).

I was going to try this tonight but didnt want to tear down my jig for drilling vent holes and then realized I dont have a bottoming tap either so there was that. The trick will be figuring out how much to put in the hole. Not enough and your left in no mans land not knowing how far it came up the threads. Too much and you have a mess. Im not very hopeful but I do hope it works! Good luck!

How are going to set up your test rig? I am about to jb weld a nut to a plate and try the test tomorrow night.

 

[fafrd]

I was going to try this tonight but didnt want to tear down my jig for drilling vent holes and then realized I dont have a bottoming tap either so there was that. The trick will be figuring out how much to put in the hole. Not enough and your left in no mans land not knowing how far it came up the threads. Too much and you have a mess. Im not very hopeful but I do hope it works! Good luck!

You are correct when it comes to the final install, but for this dry run / test my goal is to make a mess...

How are going to set up your test rig? I am about to jb weld a nut to a plate and try the test tomorrow night.

I’m going to JB Weld my female thread onto one side of a bumper washer to seal off the hole, then I have a hex nut just big enough to slip onto the sleeve, so I will JB Weld than on to provide torque.

I found a 1/4” version of this post at Home Depot which was open-ended on both ends: https://www.homedecorhardware.com/h...o9FnZnxqHJagZdapSUncTwq8hkDymXXRoCqv4QAvD_BwE

I’ll probably glue the jig together and then give it 48-72 hours to cure before running the test...

 

[zzyzx]

1/ What to do with pristine / new threads (if such a thing even exists - I didn’t think to inspect before playing with mine). The consensus seems to be that Loctite Red is best for this situation.

OK, I admit I haven't done anything with MY pristine threads as I have not received any cells yet.

However, I was planning on inserting an M6 Helicoil (based on other discussions) to protect the aluminum threads, but that no longer seems to part of the "virgin" thread discussion? Is that no longer a preferred method to protect new threads?

And if it is still useful, would Loctite Red or JB Weld still be used when a 20mm/25mm SS grub screw is attached for the first time? I was under the impression that the Helicoil would make an even stronger connection with the threads and then some application of a threadlocker or ??? to seal the deal. Obviously, a top hex wrench would still be used hold the grub screw stationary while tightening nuts.

Someone, PLEASE enlighten me! ?️

 

[noenegdod]

Yes I was talking about the final install as for the mess. For the test Im going to fill it right up too and see how far it gets.

Here is my test rig. Am going to try it tomorrow night.

 

[fafrd]

OK, I admit I haven't done anything with MY pristine threads as I have not received any cells yet.

However, I was planning on inserting an M6 Helicoil (based on other discussions) to protect the aluminum threads, but that no longer seems to part of the "virgin" thread discussion? Is that no longer a preferred method to protect new threads?

And if it is still useful, would Loctite Red or JB Weld still be used when a 20mm/25mm SS grub screw is attached for the first time? I was under the impression that the Helicoil would make an even stronger connection with the threads and then some application of a threadlocker or ??? to seal the deal. Obviously, a top hex wrench would still be used hold the grub screw stationary while tightening nuts.

Someone, PLEASE enlighten me! ?️

Helicoil should be stronger than the base aluminum thread but is a more effort and more cost. If you have a need to remove your grubscrews (ever), that’s probably the better way to go.

My goal is to permanently affix grubscrews to my terminals, so Loctite Red is probably the easiest way to achieve that and JB Weld may fi the job as well (but is more justified when threads are already worn or even partially stripped, versus pristine).

If I had new cells coming in, so would use Loctite Red to affix grubscrews before threading anything into those threads.

Helicoil is always there as a fall-back if you ever pull the entire grubscrew with threads and Loctite out...

 

[fafrd]

Yes I was talking about the final install as for the mess. For the test Im going to fill it right up too and see how far it gets.

Here is my test rig. Am going to try it tomorrow night.

Cool.

The binding posts I’m using are a bit longer than that nut. They even make aluminum binding posts in case I want to get serious about create some partially-stripped threads and seeing how well JB Weld secures a grubscrew to them: https://www.amazon.com/Aluminum-Binding-Posts-Screws-Pack/dp/B00FSY0YJA

I’m not in a rush, so I may even get some of these and try both JB Weld and Loctite Red on them.

You could torque these until they pull out and if the Loctite Red lasts as long as the JB Weld, no reason to consider JB Weld for pristine / unused threads.

Then you could strip the first however many threads and repeat the test.

 

[fafrd]

Lowe’s has #8 3/8” long binding posts made out of Aluminum: https://www.lowes.com/pd/Hillman-8-x-3-8-in-Silver-Plain-Flat-Interior-Binding-Post-Screws/3012648

JB Weld a nice strong nut around that post, get a #8 bolt, and you could do a very good job simulating what will be happening in our cell terminals...

 

[noenegdod]

I tested out the epoxy tonight and admittedly it came out of the nut a lot easier than I expected. Even at two or three times the depth it would be still come out, you would just have to go slow and apply steady pressure. I used 1/4 20 nut and bolt, not 6mm.

That said, Im still putting vent holes in all my studs for the simple reason that I don't want any epoxy getting on the terminal contact surface. I could not remember for sure what the material was but in the past I remembered not being able to remove epoxy smudges from a surface after clean up. I tried it this time on a piece of aluminum foil. I put a small dab on the foil and wiped it off. Then wiped it several times with acetone, then Toluene and finally with brake cleaner and the smudge remained. I have no idea if it would have any impact on conductivity or not but for me its not worth trading time drilling holes in studs for trying to do a perfect clean up job and possibly/probably never actually achieving it. Not making the mess is probably better than cleaning it up IMO

 

[fafrd]

I tested out the epoxy tonight and admittedly it came out of the nut a lot easier than I expected. Even at two or three times the depth it would be still come out, you would just have to go slow and apply steady pressure. I used 1/4 20 nut and bolt, not 6mm.

That said, Im still putting vent holes in all my studs for the simple reason that I don't want any epoxy getting on the terminal contact surface. I could not remember for sure what the material was but in the past I remembered not being able to remove epoxy smudges from a surface after clean up. I tried it this time on a piece of aluminum foil. I put a small dab on the foil and wiped it off. Then wiped it several times with acetone, then Toluene and finally with brake cleaner and the smudge remained. I have no idea if it would have any impact on conductivity or not but for me its not worth trading time drilling holes in studs for trying to do a perfect clean up job and possibly/probably never actually achieving it. Not making the mess is probably better than cleaning it up IMO

Cool.

I’ll be trying mine tomorrow.

I’m considering only putting a big dollop of JB Weld on the center bottom of the bolt so that it will only come in contact with the hole/base and start to ooze upwards through the thread gap after it reaches the bottom.

Based on what you saw today, would you think that is an approach worth trying?

 

[Gazoo]

That said, Im still putting vent holes in all my studs for the simple reason that I don't want any epoxy getting on the terminal contact surface.

If you do get any on the terminal, and I will be surprised if you avoid it no matter what you do, take a paper towel and wipe it off. Some might continue to ooze up the threads for the first 15 minutes or so.

Once you are satisfied the terminal is clean wait until the JB Weld starts to cure, maybe an hour or so. Then take acetone and lightly wipe off the terminal. It won't leave a smudge if you wipe it off early. It will take the full 24 hours to cure. I waited two days before I put my cell back into service.

 

[FilterGuy]

If you do get any on the terminal, and I will be surprised if you avoid it no matter what you do,

You need the BINFORD 43000!



Slide it over the post and twist

 

[ArthurEld]

You need the BINFORD 43000!

View attachment 35999

Slide it over the post and twist

That would be easy to make. I've been rubbing all of my terminals with scotchbrite.
I could do something similar with scotchbrite too.

But what would be really great is to rig something like that with cloth on the end for putting on Noalox. I like to just put on a thin layer with no globs. And locked in studs make these tasks a pain.

 

[noenegdod]

Based on what you saw today, would you think that is an approach worth trying?

The reason Im not is consistency. Overfill the hole a little and you get excess on the terminal, Underfill and your stud isnt as secure as it could be.

If you do get any on the terminal, and I will be surprised if you avoid it no matter what you do, take a paper towel and wipe it off. Some might continue to ooze up the threads for the first 15 minutes or so.

Once you are satisfied the terminal is clean wait until the JB Weld starts to cure, maybe an hour or so. Then take acetone and lightly wipe off the terminal. It won't leave a smudge if you wipe it off early. It will take the full 24 hours to cure. I waited two days before I put my cell back into service.

I wiped the foil immediately after I was done doing the test, within 5 min, with acetone, toluene and brake cleaner. The smudge persisted. Not doing that unless I have to.

Epoxy isnt really compressible so there is only two reasons I can think of that any would continue to come up after. First is if you have trapped air in the hole and it is under pressure and is pushing epoxy up the hole and second is if the stud wasnt fully at the bottom of the hole and is continuing to creep down displacing epoxy and pushing it up.

You need the BINFORD 43000!

I have a machinist making me one right now!

 

[Pyrofx]

If you want to get a stud out that is locked in with red thread locker you have to heat it to 450 degrees.
To do that, they recommend touching the stud with a soldering iron. Then turning the stud out while hot.
I don't know how to tell when the stud is 450 degrees.

The stud moves ?

 

[Pyrofx]

When playing with jb or locktite. Use a TINY amount. Almost like it's not there. Put some on the stud and some on the femail threads. We aren't dealing with Grand Canyon gaps here.

Oh. And learn what INCH POUNDS are. I've dealt with aluminum exotic engines since I was 10. Never stripped a single bolt. I'm thinking a lot of people building these have not built many odd projects that require finesse. That's not a knock. Experience is a life teacher.

 

[ArthurEld]

When playing with jb or locktite. Use a TINY amount. Almost like it's not there. Put some on the stud and some on the femail threads. We aren't dealing with Grand Canyon gaps here.

Oh. And learn what INCH POUNDS are. I've dealt with aluminum exotic engines since I was 10. Never stripped a single bolt. I'm thinking a lot of people building these have not built many odd projects that require finesse. That's not a knock. Experience is a life teacher.

The holes are getting stretched buy cell swelling and solid busbars. Also people move the cells with a fixture while the busbars are tight.
I've turned a lot of screws too. Sadly I stripped another one once many years ago.