Fixing a faulty pivot

Joined
Dec 3, 2018
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950
Hi BF's

I purchased a custom/mid-tech knife on the exchange. The knife I received had an apparent issue with the pivot loosening. I tightened the pivot hoping it was just loose, but after a dozen flips it had undone itself again.

I don't have any experience with loctite, but decided to give it a go. I watched a few videos and acquired a tube of Permatex medium strength blue thread locker. I applied the thread locker and placed the knife in a zip lock bag with the air squeezed out of the bag for the thread locker to cure. I waited a full 24 hours to allow it to cure before trying the action. The thread-locker only briefly delayed the pivot from becoming undone. I repeated the process two more times using increasing amounts of the blue goo (although this brand seems watery) to hold the pivot in place without any success.

I contacted the maker in an attempt to purchase a new pivot, but he essentially told me to F off because the knife was not purchased directly from him personally.

I'm not really sure what to do from here so I'm seeking assistance. This is the first knife I have used locktite on. Is the Permatex medium strength blue thread-locker an acceptable product to use on knife pivots or should I purchase the name brand Loctite to see if it makes a difference? Should I jump up to the red full-strength stuff since the medium strength stuff isn't able to hold the pivot together?

What would be potential costs/hurdles/time investment of finding a different maker/craftsman to fabricate a new pivot for someone else's design? Is there any other options to remedy my pivot problem?

I appreciate any feedback or advice. Despite my poor experiences with the dbag maker, I really like this knife/design. It suits my tastes perfectly to the point I would be singing the makers praises if it wasn't for the fatal flaw and subsequent negative interactions with the maker. I did contact the seller immediately upon IDing the issue. He offered a full refund no questions asked. Since I really like the knife, I declined and he provided me some loctite tips. I don't feel right about asking him for a refund after initially declining his offer and attempting multiple times to fix the issue myself. I also can't afford to throw away $425 on a knife that isn't safe to use. Fixing the issue is the best course of action...I just don't know how to do that.

Thanks for any assistance you guys are able to provide.
 
Did you clean the pivot to remove all oil before applying the thread locker? If not, try again after cleaning the threads with degreaser or alcohol...that's probably your problem.
 
Did you clean the pivot to remove all oil before applying the thread locker? If not, try again after cleaning the threads with degreaser or alcohol...that's probably your problem.

I did clean the screws with an alcohol pad (91% alcohol). I let the screws air dry before applying the thread-locker. I repeated this step every time I applied the thread-locker.

Although...I never completely disassembled the knife. I just removed the pivot screw, cleaned/dried it, applied the thread-locker, re-inserted the screw, tuned it to an acceptable action, & then placed it in a zip lock bag with the air squeezed out for 24 hours.

Any thoughts on the brand of thread-locker (Permatex)? Should I try the name brand stuff? Should I move up to the Red stuff?

I would appreciate any further tips. Thanks
 
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I did clean the screws with an alcohol pad (91% alcohol). I let the screws air dry before applying the thread-locker. I repeated this step every time I applied the thread-locker.

Although...I never completely disassembled the knife. I just removed the pivot screw, cleaned/dried it, applied the thread-locker, re-inserted the screw, tuned it to an acceptable action, & then placed it in a zip lock bag with the air squeezed out for 24 hours.

Any thoughts on the brand of thread-locker (Permatex)? Should I try the name brand stuff? Should I move up to the Red stuff?

I would appreciate any further tips. Thanks
God no, red Loctite is permanent and requires heat to loosen. Even blue Loctite is overkill for these tiny screws, purple is really the correct stuff. If you didn't clean the oil from the threads on the screw AND the threads inside the pivot barrel that could still be your problem.

The only threadlocker I use on knives is Loctite 243, it's the oil resistant version of the standard blue 242 (but you still have to apply to an oil free surface, it just resists breakdown after curing).
 
a second on definitely no RED loctite ... you'll end up with a bad pivot that you can't work on ...

I would recommend giving Josh @ REK Sharpening a call ... I don't know what brand of knife it is to offer advice if I have any experience with it ...

but Josh will most likely be able to help you ... or fix it if it's possible ... he is about as good as I've met with knives ... and really good to work with.
 
God no, red Loctite is permanent and requires heat to loosen. Even blue Loctite is overkill for these tiny screws, purple is really the correct stuff. If you didn't clean the oil from the threads on the screw AND the threads inside the pivot barrel that could still be your problem.
The only threadlocker I use on knives is Loctite 243, it's the oil resistant version of the standard blue 242 (but you still have to apply to an oil free surface, it just resists breakdown after curing).

I will try again to remedy the issue with the Permatex loctite. I will make a concerted effort to remove any oil/grit/gunk from the screw/pivot barrel. I’m not above considering I made a error, so I will be thorough to rule out user error.

If the issue persists, I will repeat the process again with the Locktite 243 you suggested.

I will try again momentarily and check back tomorrow evening to post the results.

I could film the process as well so a well trained eye could ID any user error, but I understand that is asking a lot and no one may have the time/desire to sit through a maintenance video.
 
a second on definitely no RED loctite ... you'll end up with a bad pivot that you can't work on ...

I would recommend giving Josh @ REK Sharpening a call ... I don't know what brand of knife it is to offer advice if I have any experience with it ...

but Josh will most likely be able to help you ... or fix it if it's possible ... he is about as good as I've met with knives ... and really good to work with.

Thanks. If I’m not able to resolve the issue after implementing the recommendations above and/or trying the Locktite 243...I will contact Josh to see if he is able to help.
 
I would let the thread locker set NOT in a sealed bag. Im thinking not interacting with air is keeping it from curing.
Please do not use red thread locker.
 
I would let the thread locker set NOT in a sealed bag. Im thinking not interacting with air is keeping it from curing.
Please do not use red thread locker.
True threadlocker is an anaerobic adhesive, the absence of oxygen is what causes it to harden. That being said, the baggy thing is pointless...both because you won't remove all the air and it's the tightening action/ pressure that drives the air away from the Loctite.
 
Sounds like the pivot itself rotates slightly during opening/closing and loosen the screw by this movement (maybe?).
I'd recommend to try thread locker from another brand (not permanent for sure), if it does not help - try to replace the screw with longer one (if there is an additional space and threading in pivot). And lastly - replacing the whole pivot assembly.
 
Are you putting the thread locker on the pivot screw or in the female? For blind holes loctite is supposed to be applied into the female or both. I use a toothpick to put a drop on the female threads.
 
Yeah you need to completely degrease both the screws and the bushing /nut (female threads).

This is what I use and it works very well.
 
Yeah you need to completely degrease both the screws and the bushing /nut (female threads).

This is what I use and it works very well.
After a thorough cleaning and another round of Permatex...it failed to hold again. I am repeating the process with the Locktite brand thread locker. If it doesn’t work this time...I’d rather just pay someone to fix.

Would you be interested?
 
After a thorough cleaning and another round of Permatex...it failed to hold again. I am repeating the process with the Locktite brand thread locker. If it doesn’t work this time...I’d rather just pay someone to fix.

Would you be interested?
I'd be happy to look at it and see if I can figure out the issue and see what can be done :)
 
I would suggest in the strongest terms that Using alcohol as a "degreasing" solvent is a waste of time.

Go to an auto parts store and buy your self a can of brake part cleaner.

Avoid the Non-Chlorinated kind, which typically comes in a green can.

You want to avoid as much as possible to avoid getting either type on Micarta or G10 or any other plastic components (don't worry about Teflon or Nylon)

but you want anything you are attempting to "Lock" to be free of oils of any kind.

Remember that loctites of any kind are similar in chemistry to super-glues and like them are inhibited by oils and dissolved with Acetone.
 
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