I've seen much debate on Loctite vs. helicoil, etc. to strengthen studs. I'd say helicoils are the way to go if you want the strongest option, but I decided to go with red loctite since my threads seemed pretty good.
I did my first 4 cells and ended up making a bit of a mess of the terminals. The challenge is that the loctite pushes out the top of the hole as it goes down (hydraulic pressure). The loctite mess was causing poor connections and it was a pain to remove.
The process I used on the rest of my cells worked very well. As follows:
Cleaned terminal top and threads with acetone and q-tips, blow dry.
Apply a small piece of electrical tape to each terminal. This will prevent loctite from contaminating the terminal surface and allows generous use of the loctite.
Use a large drill bit to cleanly cut out the terminal hole. If you spin the bit backwards by hand, it cuts out the electrical tape and doesn't do anything to the aluminum. (edit - the drill bit should be much bigger than the hole, it's cutting on the top, doesn't go into the hole)
Apply primer (improves bond/strength with aluminum and stainless). Rather than spraying, I just shoot some in the cap and use a q-tip to apply to the terminal threads and studs. Let it dry for 5 minutes. I used a little compressed air to make sure the holes are dry.
Apply loctite generously to threads in terminal hole and just a little on the first couple threads of the stud. Screw the stud into the terminal slowly, rocking it as you go. You can see the bubbles work themselves to the surface. Take it to the the bottom of the hole and back off just slightly. You end up with extra loctite around the based of the stud that needs to be wiped up carefully so that you don't get any on the exposed stud.
After wiping up the extra loctite, I put a bus bar on with a couple washers and nut to properly seat the stud. I think this step is important because there is some slop in the threads and you want it to set up in a nice straight position with threads fully engaged. I let it set for at least 12 hours before removing the bus bar and tape. Use acetone to clean off any residual adhesive from the tape and then good to go. They say 24 hours for complete cure.
So far, so good. I'm assembled and disassembled one of my packs at least 5 times with 35 in/lbs of torque and they seem really solid. I guess it always seem solid until it's not.... Time will tell how things hold up.
I did my first 4 cells and ended up making a bit of a mess of the terminals. The challenge is that the loctite pushes out the top of the hole as it goes down (hydraulic pressure). The loctite mess was causing poor connections and it was a pain to remove.
The process I used on the rest of my cells worked very well. As follows:
Cleaned terminal top and threads with acetone and q-tips, blow dry.
Apply a small piece of electrical tape to each terminal. This will prevent loctite from contaminating the terminal surface and allows generous use of the loctite.
Use a large drill bit to cleanly cut out the terminal hole. If you spin the bit backwards by hand, it cuts out the electrical tape and doesn't do anything to the aluminum. (edit - the drill bit should be much bigger than the hole, it's cutting on the top, doesn't go into the hole)
Apply primer (improves bond/strength with aluminum and stainless). Rather than spraying, I just shoot some in the cap and use a q-tip to apply to the terminal threads and studs. Let it dry for 5 minutes. I used a little compressed air to make sure the holes are dry.
Apply loctite generously to threads in terminal hole and just a little on the first couple threads of the stud. Screw the stud into the terminal slowly, rocking it as you go. You can see the bubbles work themselves to the surface. Take it to the the bottom of the hole and back off just slightly. You end up with extra loctite around the based of the stud that needs to be wiped up carefully so that you don't get any on the exposed stud.
After wiping up the extra loctite, I put a bus bar on with a couple washers and nut to properly seat the stud. I think this step is important because there is some slop in the threads and you want it to set up in a nice straight position with threads fully engaged. I let it set for at least 12 hours before removing the bus bar and tape. Use acetone to clean off any residual adhesive from the tape and then good to go. They say 24 hours for complete cure.
So far, so good. I'm assembled and disassembled one of my packs at least 5 times with 35 in/lbs of torque and they seem really solid. I guess it always seem solid until it's not.... Time will tell how things hold up.
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