Recommendation? Problems with locktite

darth_cholo

darth_cholo

Joined
Mar 29, 2010
Messages
392
I have a sort of different question that the usual. I can't get locktite to stick and do it's job. I have a Spyderco PM2 that keeps loosening after about 50 flicks. I don't want to keep tightening each time I notice the incremental increase in blade play. I tried applying over existing loctite and that failed. I took out screws and pivot and put in acetone and cleaned out threads with toothpick as much as possible. That didn't work after 48 hrs of letting it cure sitting untouched.

My recent attempt was removing screws and applying different brand of loctite. (Permatex to Vibratite brand gel.) When I unscrewed to apply Vibratite gel the old loctite was still wet and turned white from original light blue color. I re cleaned just the screws this time.

What's my next step if the Vibratite gel doesn't work? Acetone not enough?
 
Probably the threads weren't perfectly cleaned. Acetone should work -- try reaming out the screw hole with a small brush if you can find something hat fits (dental pick?) or run a piece of cotton cord or shoe lace pull-through to get out any little bits. Red loctite is more permanent than blue.
 
It sounds like Loctite reacts with something.

Did you clean the pivot and screw with excess amount of acetone, i.e. dipping them in a large volume?
If not, try dipping them in ethanol after acetone, rinse with running water, and dry.

Alternatively, the thread locker was old, and you squeezed out only the solvent but not much of the reactant.
 
miso2 said:
It sounds like Loctite reacts with something.

Did you clean the pivot and screw with excess amount of acetone, i.e. dipping them in a large volume?
If not, try dipping them in ethanol after acetone, rinse with running water, and dry.

Alternatively, the thread locker was old, and you squeezed out only the solvent but not much of the reactant.
Click to expand...
I submerged in acetone for a couple hours in a mini water bottle and and shook with the cap on a few times. It was old loctite (about 6 years old) so it could of been that. It might take a few days to find out if the new Vibratite worked. Otherwise I'm gonna do another overhaul with some flossers with brustles in the inside of the pivot too.
 
you may be applying too much? I generally only put a very small drop on the screw.
 
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I found an interesting description on Loctite web page.

"Blooming or frosting is a phenomenon that occurs when cyanoacrylate monomer vapourises and reacts with moisture in the surrounding environment and falls back down on the part, leaving a white powdery residue behind. (Interesting fact: it is actually used by detectives to find finger prints at crime scenes.) There are several ways to prevent blooming such as sufficient ventilation over the assembly area, applying less adhesive and/or curing the adhesive faster. The other option is to simply use a LOCTITE Low Odour / Low Bloom instant adhesives which is less volatile and thus less likely to bloom."

Also,

"Anaerobics, that include many of our threadlockers, pipe sealants, retaining compounds and flange sealants, are products that cure in the absence of air. These are products that are designed for metal-to-metal assemblies although they are sometimes used for other materials as well."
 
I think maybe I put too much. Usually when applying locktite I'm screwing something down really tight forcing the locktite out of any area where too much was applied. In this application I'm keeping them loosy goosy to prevent binding.
 
The Acetone wash might have left a greasy residue i always finish with alcohol, then use the red loctite only not the other colors and give it 24 and more hours to cure.
 
Thanks for suggestions but I'm ready to give up. Let the knife sit for 5 days, screws still move after 20 flicks. It's possible the thicker aftermarket scales are preventing screws from screwing into the pivot enough to engage loctite. After acetone and really agitating with q tips in the pivot and scraping the screws with toothpicks, I rinsed with water and then with alcohol. Light dabs of blue loctite on the screws and waited 5 days. I probably took about 2-3 minutes after applying loctite before laying it to cure. I tighted the screws and backed them out only once to keep adjustments minimal.

I'll put the original smooth G10 scales back on on and retry. This time I'll put the loctite on inside the pivot instead of screws, or perhaps find some slightly longer screws to compensate for the thicker aftermarket scales.
 
I have a few knives like that with pivot screws loosening constantly.
I ended up using red Loctite.
Can't recommend it for free spinning pivot, though.

Alternatively, you can try Teflon tape.
It does help.
You need to put little more than you think sufficient.
 
Don't use red Loctite if you ever want to easily separate the parts in the future, with the small torx driver that screw takes. Blue Loctite and just a small drop. Shake the bottle every time before using the Loctite. Assembling spreads it sufficiently. Do as you said, re-clean the threads with either alcohol or acetone ( acetone does not leave a greasy residue ). Don't rinse with water, just allow to dry or soak up excess with a paper towel or Q-tip twisted into the threads or blow them out with air.
 
miso2 said:
I have a few knives like that with pivot screws loosening constantly.
I ended up using red Loctite.
Can't recommend it for free spinning pivot, though.

Alternatively, you can try Teflon tape.
It does help.
You need to put little more than you think sufficient.
Click to expand...
I might try some red loctite. It's a pm2 so it's not free spinning (d shaped in one side).

One more try with blue and maybe some Vibratite nylon lock and then I'm going for red.
 
Hmmm.
PM2 should be fine with blue.

If you have a good torx driver, red Loctite would not be much of an issue.
But sometimes you need to heat up the pivot to loosen it.
Since PM2 scales are synthetic, heating (500F) is not gonna be an option.

So I would suggest you try Teflon tape before going for red.
 
Got home. Removed a screw. Loctite isn't curing. It's still wet. Rubbed if off with qtip. Applied 5 days ago. Too much?. Here is the second screw freshly removed.
7RoaVXi.jpg
 
You can apply it somewhere else, another knife maybe.
If it doesn't cure there, the chemical is probably old and bad, or not mixed enough.

Edit: You don't have to wait overnight. It should solidify to some extent after 1 hour.
 
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I don't have any problems the Permatex Blue stuff and I even have some really old stuff and it always works fine,try putting a drop in the hole and use a needle to stir it a bit because most times it form's a bubble and won't run in the hole and apply a tiny bit to the bolt as well.

With the PM2's I have and I have about 4 of them on everyone the the pivot is indexed on one side so the pivot can't turn and cause the screws to loosen,try what I I said above and wait about 1 hour for the locktite to set up and you should fine don't use the red stuff it's to hard on the screws if you want to take it apart later on,I also have Allen Putman scales and I have no problem's with any of my knives using his scales.

I also find with locktite the part don't need to be cleaned to point you cleaned them most times I just use soapy water to get rid of the oil and rinse them off off under hot water and then dry them off,I also never clean off old locktite I just apply over the old stuff most times and unless the stuff you had left on was really soft that's about the only thing I could see that may have caused a problem.
 
darth_cholo said:
Got home. Removed a screw. Loctite isn't curing. It's still wet. Rubbed if off with qtip. Applied 5 days ago. Too much?. Here is the second screw freshly removed.
7RoaVXi.jpg
Click to expand...

Now I see that the chemical doesn't really spread in the threads, indicating that the male and female parts are not really fit.
Is this the original screw?
 
miso2 said:
Now I see that the chemical doesn't really spread in the threads, indicating that the male and female parts are not really fit.
Is this the original screw?
Click to expand...

Yes original screw from a new smooth g10cruwear
 
If the space between male and female threads is small, the chemical should be spread and distributed more evenly than what is shown in your pic.
Or does it?

If not, maybe assembled with wrong pivot at the factory?
You should probably send it back to Spyderco.

All assuming that you got a genuine PM2 new from a respected dealer.
I believe mine (S110V) came new with red Loctite in the pivot.
Yes, it is still there.

IMG_1154.JPG
 
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