Sixtysix 280ah Cells from Deligreen

[fafrd]

I finished the capacity test. According to the BMS I got 262.2Ah. The battery monitor showed that I got 270Ah.
I don't know which is correct. Cell 14 hit the limit first again.
I will use it as is.

On to the next one.

I also torqued all of the terminals to 35 in lbs.

So sounds like you are pretty happy with Loctite Red and convinced it will deliver 4Nm / 35 inch-lbs of torque.

Are you going to stop there or try getting up to 40 or 45 inch-lbs?

From what you’ve now experienced, do you believe Loctite Red would do a good job salvaging partially-stripped threads (top 3 out of 5 threads stripped) or would you go with Helicoil for that situation instead?

After seeing that JB Weld strength test video, I’m on the fence about trying that to salvage my partially stripped thread or giving Red Loctite a try.

My logic is that JB Weld should be stronger for salvaging that partially stripped thread, so I could try that first.

If is is a PITA I can switch to Loctite Red for all of the other threads;

And if I find it about as easy as you found using Loctite Red, I can just continue to use JB Weld for all of my terminals...

Thoughts?

 

[fafrd]

I meant charge controller. I have a MPP Solar 3048 all in one.
I measured the amps on the cable that goes to the battery.

How? With a clamp-meter or with an in-line DC Ammeter?

I have a multimeter and a clamp meter for checking amps.
I do not have a water heater or a device that I know the expected amps. But I will look for one.
Maybe my heat gun would work.

Thanks for the replys

A heat gun is AC and will not work (unless you can measure a resistance through it, in which case it might).

I have a 600W 120V AC electric charcoal starter. It is a passive resistance measuring ~23 Ohms.

So if I connect that to my 24VDC battery I will get just over 1A of current.

That same connection through my DMM Ameter in series allows me to measure that current at the same time it is flowing.

A kitchen hotplate is another passive DC heating element - what you need is either the raw heating element or the heating element in a device with nothing other than a plain ol’ switch (no brains / fancy electronics that need 120VAC to operate properly).

 

[ArthurEld]

So sounds like you are pretty happy with Loctite Red and convinced it will deliver 4Nm / 35 inch-lbs of torque.

Are you going to stop there or try getting up to 40 or 45 inch-lbs?

I don't think I need to torque to 40 or 45 but I will probably give it a try. I will have to time it so I can comfortably stop and put a helicoil in if I need to.
The only reason I would torque to 45 in lbs is because I think they should take 45 in lbs to be safe. There are a lot of ways to cause extra pressure on the threads. So even if they are torqued to 35 in lbs, there is a good chance that something will cause them to get pulled to 45 in lbs. At least for me because I am using solid busbars. The cells could move from inflation and there are a lot of other reasons a cell could move a little and it shouldn't cause the screws to pop out.

From what you’ve now experienced, do you believe Loctite Red would do a good job salvaging partially-stripped threads (top 3 out of 5 threads stripped) or would you go with Helicoil for that situation instead?

I am fairly sure I partially stripped one of my threads. There were other terminals with threads that were loose. The threads were sloppy even with the screw turned in just off the bottom. I could move the stud around. The studs all feel solid now.
But I will still have to give them the 45 in lb torque test just to be sure.

After seeing that JB Weld strength test video, I’m on the fence about trying that to salvage my partially stripped thread or giving Red Loctite a try.

My logic is that JB Weld should be stronger for salvaging that partially stripped thread, so I could try that first.

If is is a PITA I can switch to Loctite Red for all of the other threads;

And if I find it about as easy as you found using Loctite Red, I can just continue to use JB Weld for all of my terminals...

Thoughts?

I know helicoils are strong and dependable. Dependable is important. It can be dangerous if these threads give way.

From what I gather, thread locker can be really strong if done right. I didn't want to count on thread locker or JB weld for completely torn out threads. But people do. People have broken off loctited stainless steel screws trying to force them out. That sounds like holding power to me.

 

[fafrd]

I don't think I need to torque to 40 or 45 but I will probably give it a try. I will have to time it so I can comfortably stop and put a helicoil in if I need to.
The only reason I would torque to 45 in lbs is because I think they should take 45 in lbs to be safe. There are a lot of ways to cause extra pressure on the threads. So even if they are torqued to 35 in lbs, there is a good chance that something will cause them to get pulled to 45 in lbs. At least for me because I am using solid busbars. The cells could move from inflation and there are a lot of other reasons a cell could move a little and it shouldn't cause the screws to pop out.

I am fairly sure I partially stripped one of my threads. There were other terminals with threads that were loose. The threads were sloppy even with the screw turned in just off the bottom. I could move the stud around. The studs all feel solid now.
But I will still have to give them the 45 in lb torque test just to be sure.

I know helicoils are strong and dependable. Dependable is important. It can be dangerous if these threads give way.

From what I gather, thread locker can be really strong if done right. I didn't want to count on thread locker or JB weld for completely torn out threads. But people do. People have broken off loctited stainless steel screws trying to force them out. That sounds like holding power to me.

That’s a good point. On the other hand, those may have been intact threads.

If you used Loctite Red on partially-stripped threads and studs that were loose in the threads, that’s a reason to think it could be a good solution for repairing partially-stripped threads like the one I have.

On the other hand, the only reason I can think of to prefer Loctite Red over JB Weld for permanent stud attachment is if JB Weld is a lot messier and more trouble overall to use for this application.

You’rd posts have been very helpful and I’m confident I understand the (lack of) complexity involved in using Loctite Red.

Even though I believe several Forum members have used JB Weld, they must be off enjoying their batteries / lives because none of them have piped up with any comments on the experience.

So I’m thinking I may be the Guinea Pig and try JB Weld on my partially-stripped thread. You’ve helped me to understand that even in the event of a mess/failure, Helicoil presents a solid back-up solution to salvage the cell...

Have you measured the resistance between your stainless studs and the aluminum terminal surface? Would be interesting to understand whether you measure any difference between the Loctite Red and the Helicoil (as well as any naked Stainless-against-Aluminum resistance if you still have untreated cells)...

Of course, resistance is likely to be below the sensitivity limit of your DMM, so measuring voltage drop at some constant charge or discharge current applied through the studs only is more likely to be meaningful...

 

[MisterSandals]

So I’m thinking I may be the Guinea Pig and try JB Weld on my partially-stripped thread.

With so many bloated and damaged cells around, it'd be a shame to experiment on a good cell...

 

[fafrd]

With so many bloated and damaged cells around, it'd be a shame to experiment on a good cell...

If anyone with a damaged cell wants to offer to test JB Weld on it, I can hold off.

But I’ve got one cell with damaged threads (top 3 out of 5 threads stripped) so that is the cell I was going to use for this experiment.

2 unanswered questions:

1/ How much stronger / better is JB Weld than Loctite Red for recovering partially-stripped threads (permanently)?

2/ How much more complicated / messy is glueing in a grubscrew / threaded post with JB Weld compared to the apparent ease of using Loctite Rex?

Inquiring Minds want to know...

 

[ArthurEld]

With so many bloated and damaged cells around, it'd be a shame to experiment on a good cell...

The first cell I put a helicoil in was a bad cell. But the threads were good on the hole I used. I should have done a loctite test before I put the helicoil in.

 

[ArthurEld]

If anyone with a damaged cell wants to offer to test JB Weld on it, I can hold off.

But I’ve got one cell with damaged threads (top 3 out of 5 threads stripped) so that is the cell I was going to use for this experiment.

2 unanswered questions:

1/ How much stronger / better is JB Weld than Loctite Red for recovering partially-stripped threads (permanently)?

2/ How much more complicated / messy is glueing in a grubscrew / threaded post with JB Weld compared to the apparent ease of using Loctite Rex?

Inquiring Minds want to know...

You could find any piece of aluminum more than 1/3 inch thick and replicate the test. You could just drill the hole and JB weld a stud in it

 

[fafrd]

You could find any piece of aluminum more than 1/3 inch thick and replicate the test. You could just drill the hole and JB weld a stud in it

That’s a good idea. At least if it makes a big mess, I’d know before I screw up my terminal.

But I’m pretty sure we’ve already heard from some members who have successfully used JB Weld to glue in threaded posts, so I believe we’d already know if it was a disaster.

I’m not really concerned about conductance, but my thought is to:

-apply JB Weld the grubscrew threads, scraping off excess with a toothpick

-apply JB Weld to terminal threads with toothpick, leaving a dollop at the bottom of the hole

-thread to the bottom lightly by hand using a hex wrench

-immediately thread a nut and tighten by finger or to a low torque to ‘raise’ the post so that top of post thread are in contact with bottom of terminal threads

This should maximize the thickness of the epoxy layer below the post thread and will also provide maximum conductance / contact between aluminum terminal and stainless grubscrew.

The only concern I really have is how much JB Weld will come squirting up out of the hole and how much of a hassle it will be to clean it all off of the aluminum surface.

In fact, I may put down some paper or tape as a sacrificial layer I can peel off, hopefully taking all of the excess JB Weld with it...

 

[Hedges]

From what you’ve now experienced, do you believe Loctite Red would do a good job salvaging partially-stripped threads (top 3 out of 5 threads stripped) or would you go with Helicoil for that situation instead?

I wouldn't expect Loctite thread locker to provide any strength in stripped threads. It is designed to provide shear strength along a thread. If probably has some strength to hold a stud in a smooth hole, but not documented.

Products sold as thread repair would have some strength, hopefully quoted as torque or pull-out values.

JB weld as an epoxy would normally have a thin bond line, but they do indicate it can be machined, so can be used as a structure. The metal particle fill may help. My math indicated it was sufficient for the relatively low torque used for these low strength aluminum terminals.

Helicoil of course puts metal in compression from stud, through the spring, to aluminum terminal. So that's going to be much better.

 

[Hedges]

-immediately thread a nut and tighten by finger or to a low torque to ‘raise’ the post so that top of post thread are in contact with bottom of terminal threads

In fact, I may put down some paper or tape as a sacrificial layer I can peel off, hopefully taking all of the excess JB Weld with it...

I would be worried about he nut getting JB Welded in place. Even if surface is cleaned off first, tightening the nut (which may be an unnecessary step) could extrude some.

Waxed paper punched over the stud, some sort of release like oil on the threads (the thread repair kits include or recommend a release substance).
Maybe put a (non threaded) standoff over the stud against waxed paper, and a nut to clamp it. No intimate contact with terminal or thread near terminal, avoiding contact with epoxy. Large enough diameter standoff and a washer for the nut, no need for waxed paper or other release material.

When using urethane glue to put down tongue and groove flooring, I clamped the boards with straps. Last board would always buckle upward, so one extra board without glue. To prevent it from bonding to the last glued down board, a sheet of waxed paper folded over the edge. Hand lotion was my way to avoid gluing my fingers in the process.

 

[Bob B]

I wouldn't expect Loctite thread locker to provide any strength in stripped threads. It is designed to provide shear strength along a thread. If probably has some strength to hold a stud in a smooth hole, but not documented.

Products sold as thread repair would have some strength, hopefully quoted as torque or pull-out values.

JB weld as an epoxy would normally have a thin bond line, but they do indicate it can be machined, so can be used as a structure. The metal particle fill may help. My math indicated it was sufficient for the relatively low torque used for these low strength aluminum terminals.

Helicoil of course puts metal in compression from stud, through the spring, to aluminum terminal. So that's going to be much better.

From their how to use document

 

[fafrd]

I would be worried about he nut getting JB Welded in place. Even if surface is cleaned off first, tightening the nut (which may be an unnecessary step) could extrude some.

There are a few options to avoid that, including use of a short 3/8” tube covered by a washer before I thread the nut.

The safe thing to do would be to tighten enough to squeeze out any JB Weld (though if the grubscrew rises, sucking some more JB Weld down seems more likely), remove everything to inspect before it has hardened, clean up anything that needs it, and then either leave it alone or reassemble whatever structure and retighten.

I’m also not terribly worried about a bit of excess hardened JB Weld around the base of the threads - if it’s enough to interfere with a lug, removing with a Dremel shouldn’t be a big deal...

Waxed paper punched over the stud, some sort of release like oil on the threads (the thread repair kits include or recommend a release substance).
Maybe put a (non threaded) standoff over the stud against waxed paper, and a nut to clamp it. No intimate contact with terminal or thread near terminal, avoiding contact with epoxy. Large enough diameter standoff and a washer for the nut, no need for waxed paper or other release material.

I’m not too worried about the thread - between lug, washer, and locknut, there will be done distance above the terminal surface before the threads are engaged by the nut.

Avoiding JB Weld between the lug and the terminal surface is my primary concern. Avoiding hardened JB Weld around the post near the terminal surface which interferes with the lug is my secondary concern, but again, some time with an appropriate dremel grinder should quickly resolve that...

When using urethane glue to put down tongue and groove flooring, I clamped the boards with straps. Last board would always buckle upward, so one extra board without glue. To prevent it from bonding to the last glued down board, a sheet of waxed paper folded over the edge. Hand lotion was my way to avoid gluing my fingers in the process.

Good idea, but hopefully this proves to be an easier problem.

My greatest concern, frankly, is trying to go too fast. Trying to use one batch of JB Weld to glue in several posts could result in a big mess. So this first go-round, I’ll only focus on that one single post on that one single (partially-stripped) thread and then I’ll see how long the remaining JB Weld remains workable.

I’m pretty confident I’ll be able to get that one post successfully glued-in with JB Weld - it just may be such a PITA that I want to switch to Loctite Red for the remaining 31 studs (I have a total of 16 cells for two 8S batteries).

 

[ArthurEld]

It sounds like a huge pain in the ass to use JB weld on all of the holes. I have never seen that advised either.
I have never used JB weld for anything so it is hard for me to give advice.

But for the holes with threads, I would use loctite.
Loctite is cheap. And it is the recommended and much easier method to lock the screws in. Acetone is the primer and cleaner.
Acetone is cheap at the drug store. You can get loctite all over and it is easy to clean up with a rag damp with acetone.

Just about any glue method can be fixed if it doesn't work so try away.

 

[Gazoo]

That’s a good idea. At least if it makes a big mess, I’d know before I screw up my terminal.

But I’m pretty sure we’ve already heard from some members who have successfully used JB Weld to glue in threaded posts, so I believe we’d already know if it was a disaster.

I’m not really concerned about conductance, but my thought is to:

-apply JB Weld the grubscrew threads, scraping off excess with a toothpick

-apply JB Weld to terminal threads with toothpick, leaving a dollop at the bottom of the hole

-thread to the bottom lightly by hand using a hex wrench

-immediately thread a nut and tighten by finger or to a low torque to ‘raise’ the post so that top of post thread are in contact with bottom of terminal threads

This should maximize the thickness of the epoxy layer below the post thread and will also provide maximum conductance / contact between aluminum terminal and stainless grubscrew.

The only concern I really have is how much JB Weld will come squirting up out of the hole and how much of a hassle it will be to clean it all off of the aluminum surface.

In fact, I may put down some paper or tape as a sacrificial layer I can peel off, hopefully taking all of the excess JB Weld with it...

Keep it simple. No need to raise the stud with a nut for a better electrical connection. No need to thread to the bottom using a hex wrench. Use your fingers and slowly screw the stud in.. No need to worry about anything squirting out.

No matter what you do some will ooze out. Wipe it all off with paper towels including any you get on the thread in the bottom area of the stud if you are concerned about that. It's better to apply too much than too little. Remember it takes 24 hours to fully cure. I let mine cure for two days.

I have done this to repair a stripped terminal...remember? It's not complicated. It's easy.

 

[Gazoo]

It sounds like a huge pain in the ass to use JB weld on all of the holes. I have never seen that advised either.
I have never used JB weld for anything so it is hard for me to give advice.

First time for everything. If I had to do it all over again I would use JB weld. But go slowly and mix several different batches as I am moving along.

But for the holes with threads, I would use loctite.
Loctite is cheap. And it is the recommended and much easier method to lock the screws in. Acetone is the primer and cleaner.
Acetone is cheap at the drug store. You can get loctite all over and it is easy to clean up with a rag damp with acetone.

JB Weld is cheap too and no primer is required. I would clean the cells threads with acetone using a q-tip. I did before I applied Loctite to my cells.

Just about any glue method can be fixed if it doesn't work so try away.

Exactly.

 

[Gazoo]

I am not suggesting anyone use the standard JB Weld on cells that have good threads. Loctite 262 would probably be fine and JB Weld makes thread lockers...permanent ones too.

 

[ArthurEld]

First time for everything. If I had to do it all over again I would use JB weld. But go slowly and mix several different batches as I am moving along..

We want pictures.

 

[fafrd]

Keep it simple. No need to raise the stud with a nut for a better electrical connection. No need to thread to the bottom using a hex wrench. Use your fingers and slowly screw the stud in.. No need to worry about anything squirting out.

No matter what you do some will ooze out. Wipe it all off with paper towels including any you get on the thread in the bottom area of the stud if you are concerned about that. It's better to apply too much than too little. Remember it takes 24 hours to fully cure. I let mine cure for two days.

I have done this to repair a stripped terminal...remember? It's not complicated. It's easy.

I recall a discussion in some thread somewhere when I first engaged with the Forum that a member had used JB Weld - it was you! (seems like a lifetime ago)

So clean up is easy with a paper towel and the best strategy is to overfill and clean up whatever oozes out of the top - thanks.

The 3 questions I have for you are:

1/ Is the stripped thread you have repaired with JB Weld as strong as your non-stripped threads (locked with Loctite or JB Weld)?

2/ What maximum torque have you applied to the terminal repaired with JB Weld?

3/ I know you said you would not recommend JB Weld to secure grubscrews in non-stripped terminals, but if you had a mixture of some stripped terminals and others that are not fully stripped but are worn, would you use JB Weld for all of them or only the few that are fully stripped?

 

[Gazoo]

1/ Is the stripped thread you have repaired with JB Weld as strong as your non-stripped threads (locked with Loctite or JB Weld)?

I don't know yet. I will know when I reassemble my cells. Keep in mind I had no threads left. So I wouldn't expect it to be as strong as using Loctite in a cell with non stripped threads.

2/ What maximum torque have you applied to the terminal repaired with JB Weld?

3nm and I stopped. When I reassemble my cells I will try for 4nm and stop there. Your chances for success are better since you have a few threads left.

3/ I know you said you would not recommend JB Weld to secure grubscrews in non-stripped terminals, but if you had a mixture of some stripped terminals and others that are not fully stripped but are worn, would you use JB Weld for all of them or only the few that are fully stripped?

What I meant by that statement is it is a personal decision whether or not to use it on non stripped screws and I should have made that clear.

For partially or fully stripped studs I do recommend it. There may be better products for this but I was in a hurry and did not research everything that's out there. Like you, I watched the YouTube videos comparing different products and decided if the standard JB Weld doesn't work, then it's likely nothing else will.

So clean up is easy with a paper towel and the best strategy is to overfill and clean up whatever oozes out of the top - thanks.

Yes but don't overdo it either. In my case some did continue to ooze up over a short period of time...maybe 15 minutes at most. I lightly cleaned the cell's terminal with acetone to make sure there wasn't any residual left and I waited a bit to allow the JB Weld to start curing. I didn't want any acetone going down into the hole and I didn't want to disturb the stud for the remainder of the cure.

I broke off the head of a Q-tip and used the stick to apply the JB Weld to the inner part of the cell's hole where the threads were. Naturally some flowed to the bottom of the hole. I saved the mixed batch and occasionally checked it to take notice of the curing process. It did take a good long while before the JB Weld was fully cured in my mixed batch, at least the full 24 hours.

Ultimately the best thing to do is to tap the hole. But by the time one buys everything needed to properly tap the terminal, one is approaching the price of a new cell. And since I only have one stripped cell, I thought I would try this first.

I am fully aware this subject is debatable and it is an excellent debate. I am sharing my recommendations based on my own experience and the posts of others. I always look forward to other's experiences concerning the topics I am interested in, and this is one of those topics. That's my disclaimer...lol.