Threadlocker strength to use?

E

Etna

Joined
Jun 17, 2015
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444
I disassembled one of my AO Schrades to clean off some dirt and grit. Now, no matter how tightly I adjust the pivot screw, it eventually manages to work itself loose after a few days and it's quite annoying to have to tighten it up every other week, so some threadlocker is needed.

What would be a good grade of threadlocker to use? Specifically, I want something that is stronger than a blue and yet not as permanent as red. Would green be good for this?
 
I would reccomend the purple ... its the only thread locker I will use on knives ... its never failed me but its still not too difficult to remove a screw after its set ... and yes just a small amount is best
 
Etna said:
I want something that is stronger than a blue and yet not as permanent as red. Would green be good for this?
Click to expand...

Use the purple; which is much lighter strength than blue.
The key to all this thread locker business is to get the metal oil free and chemically clean. Wash the parts in solvent like carburetor cleaner then use the primer for the locktite (over kill but it feels good to over do it with "magic" elixirs . . . right )?

Green tends to be a bearing mount version of locktite for holding sealed cartridge bearings in a tubular recess to keep them from spinning. Works really well for bearings. Tends to be more crusty / hard like old varnish as compared to the stuff for threads which tends more toward chewing gum/medium hard plastic.

Trivia question . . . for the big prize behind door number three :
WHAT causes loctite to harden ?

a. evaporation of solvent
b. the absence of oxygen
c. chemical cross linking (think epoxy)
​
You have thirty seconds . . . tic . . . tock . . . tic . . . tock . . .
 
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Check out Vibra-Tite VC-3

https://www.alphaknifesupply.com/hardware.htm#HA-VC3

Otherwise purple or blue loctite works well. Purple is weaker than blue. Avoid red like the plague. Whites not so nice either. And if you need something from the store check out Teflon plumbers tape which can be good but some hate it.

In any case if blue is not working for you something else is wrong.

Wowbagger said:
WHAT causes loctite to harden ?

a. evaporation of solvent
b. the absence of oxygen
c. chemical cro
Click to expand...
B
http://www.loctite.com.au/aue/content_data/133403_LT_4985_Threadlocking_Users_Guide.pdf
 
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Vibra-Tite VC3 or Loc Tite Purple or Loc Tite Blue 242

Never use the red or white on knives.
 
I see quite a lot of suggestions for a purple threadlocking solution.

But purple is also the lowest grade in locking strength, isn't it? How can I be certain that purple will not cause the pivot screw to work itself loose over time? Not keen on buying a bottle of threadlocker solution only to find out that it does a poor job of holding the pivot screw in.
 
Ive used blue and had problems getting handle scale screws out. Dont go above blue.
 
Always blue. If you follow the directions and apply as directed you shouldn't have any issues. There are tons of videos on YT too explaining how to apply threadlocker to a small screw vs a larger one. A little goes a long way.
 
Etna said:
I see quite a lot of suggestions for a purple threadlocking solution.

But purple is also the lowest grade in locking strength, isn't it? How can I be certain that purple will not cause the pivot screw to work itself loose over time? Not keen on buying a bottle of threadlocker solution only to find out that it does a poor job of holding the pivot screw in.
Click to expand...

How can I be certain that purple will not cause the pivot screw to work itself loose over time?
Click to expand...
You mean how can you be sure the product will work as advertised ? Clean the threads with solvent and primer and use as directed.

. . . and do you really expect to need thread locker rated ABOVE 300° F ? (blue at 600° F)

The loctite site is so FREEKING LAME that they don't even list Purple; had to go to an alternate source.
Why are the .com home pages invariably more lame and less user friendly than alternate sites.
In any case I know these products from reading the packaging and using them for the last thirty years at work.

Purple
http://na.henkel-adhesives.com/industrial/purple-threadlockers-small-thread-low-strength-13233.htm

Features:
  • Low strength
  • Easy to remove liquid threadlocker
  • Typically used with small screws up to 1/4".
  • The optimum temperature range is -65º F to 300º F.

Blue
http://na.henkel-adhesives.com/industrial/blue-threadlockers-medium-strength-13231.htm

Features:
  • Removable with standard hand tools on ¼ to ¾ fasteners.
  • Available in liquid, stick, paste, gel and tape form.
  • Fast fixture times.
  • Optimum temperature range is range -65ºF to 650ºF.
PS: the "green" I was thinking of that is a bearing mount is this one
http://www.na.henkel-adhesives.com/product-search-1554.htm?nodeid=8797928521729

There is also a WICKING green using to help lock threaded assemblies that are already assembled. I find it works best on things that can be spun so that centrifugal force drives the loctite into the threads. Think spoke nipples on motorcycle spoked wheels. Put the loctite on the spoke on the hub side of the nipple and when spun the loctite travels into the top of the nipple and then into the threads of the nipple.
 
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I use the purple stuff on pivots and threaded scale fasteners. Nothing has ever cammed out with 222.
 
Recently rec'd new Kershaw Cryo, clip screws were coated in brown loctite. Hadn't ever seen the brown used before in knife parts.
 
I clean the fasteners with lacquer thinner, add a small dab of blue loctite and let it cure for 24 hours. Works for me.
 
i have purple loctite 222 but find it pretty witless. i use it only because i bought it and doht want to let it go to waste.

but it's sohh weak!!🤪

the better alternative is to employ cheap transparent paper glue like henkel uhu in order to fasten small screws. very harmless stuff, opens with a cute crack, easy to clean (can be pulled off wiv finger in one piece!). for small screws i doht experience any advantage of using henkel loctite 222 over paper glue tbh. other than feeling superior\professional. lol

buying purple loctite (15usd over here) was one of the few fails\regrets in this knife hobby. definitely waste of $$.
 
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Mo2 said:
Check out Vibra-Tite VC-3

https://www.alphaknifesupply.com/hardware.htm#HA-VC3

Otherwise purple or blue loctite works well. Purple is weaker than blue. Avoid red like the plague. Whites not so nice either. And if you need something from the store check out Teflon plumbers tape which can be good but some hate it.

In any case if blue is not working for you something else is wrong.


B
http://www.loctite.com.au/aue/content_data/133403_LT_4985_Threadlocking_Users_Guide.pdf
Click to expand...

I recently converted to Vibra Tite. Being able to tweak the pivot after assembly, and reuse the threadlocker a few times before having to reapply. Been working great so far! A bit messy to apply (I got the little jar with a brush) but I've worked out a technique where I pull out the brush and touch the screw to it. Works for me.
 
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