Which Loctite to Use?

Discussion in 'Maintenance, Tinkering & Embellishment' started by Cosmodragoon, May 21, 2019.

  1. Cosmodragoon


    Jan 1, 2019
    Hi. I know a lot of people use blue Loctite to keep screws securely in place. I've seen the stick version used by a few reviewers on the web. Do you use it? Which one do you use?
    kreisler likes this.
  2. FullMetalJackass

    FullMetalJackass Gold Member Gold Member

    Apr 10, 2016
    The blue. Don't put too much!
    marrenmiller, TheEdge01 and cwsmith17 like this.
  3. Ajack60

    Ajack60 Platinum Member Platinum Member

    Apr 21, 2013
    Purple (Loctite 222) or Teflon tape, not the thick kind. They make some that is paper thin
  4. AntDog

    AntDog Gold Member Gold Member Basic Member

    Apr 3, 2001
    Good ol 242. A little dab’ll do ya. Only run a bead down one side of the screw and you’re good to go.
    kreisler likes this.
  5. Sharp & Fiery

    Sharp & Fiery Always Embellish Knifemaker / Craftsman / Service Provider

    May 14, 2012
    Generally none. Purple or blue if i must...depends on how easily the pivot backs itself out.
    Lapedog likes this.
  6. eveled

    eveled Gold Member Gold Member

    Mar 11, 2016
    I use a product that you apply to the screw. Then let it dry. Then it stays on the threads through many cycles of use. This way there is no chance of the wet loctite oozing were it doesn’t belong.

    Vibratite VC-3
  7. sickpuppy1

    sickpuppy1 Gold Member Gold Member

    Sep 27, 2018
    Generally speaking, blue is to hold things in place that will need to be taken apart later, its considered medium strength. Good general purpose locking compound. Red is high strength and I would never use it on knives as it will take a fair amount of heat to get it loose. Purple is for use on softer metals, brass, aluminum etc. I would consider it low-medium strength. Green is considered medium-high strength and may take heat to get it loose. Should have done this in order of strength I guess. but IMO, I would only use blue or purple on a knife if I thought I was gonna need to disassemble it at all for cleaning/adjusting.
    marrenmiller and cwsmith17 like this.
  8. bobobama


    Jan 15, 2017
    I'm with you on this. Much as I love loctite I don't find much need for it on knives. I have used the purple on some of my knives but got tired of it, since it didn't really seem to be necessary. Just properly tightening the screws and regularly checking them should suffice for most needs.
  9. brando555


    Sep 26, 2018
    I use 242 and 243, but I tend to favor 243 since it is more oil resistant. 242 holds the best when you clean the threads with acetone or isopropyl first.

    243 doesn't mind a little oil, which is nice because I really only use loctite on pivot screws that have a sweet spot, or pivot screws that tend to back themselves out over time. Handle screws or standoff screws really don't need it since you can torque those down tight for the most part.
  10. Blues

    Blues Lapsed SuperMod / Cattle Knife Rustler Staff Member Super Mod

    Oct 2, 1998
    I'm a big fan of Purple 222 or 222 MS. (But I've yet to need it on a knife.)

    It works on firearms, it'll hold a knife together. (And it's not an issue removing hardware treated with it.)
    kreisler likes this.
  11. sickpuppy1

    sickpuppy1 Gold Member Gold Member

    Sep 27, 2018
    FYI 242 is blue stuff for the ones scratching their heads, and 243 is an "upgraded version" of 242, also blue. confused yet?
  12. Cosmodragoon


    Jan 1, 2019
    I have never used it. Whenever a screw has backed out a little in the past, I've just tightened it back up. The other day, I noticed that the centering on my Naja was off. It had drifted in the direction the liner lock was pushing. I was on the road and didn't have a torx bit handy. So I started this thread!
  13. Night Rider

    Night Rider Gold Member Gold Member

    Apr 16, 2018
    I use to use BLUE on the pivot screw only but since I had a screw fall out of the scale of my Spyderco I now use BLUE on everything.
    kreisler likes this.
  14. Wowbagger


    Sep 20, 2015
    Yuuuuuuup . . . this ^ is designed for tiny screws.
    Blue is for fasteners 1/4 inch and larger.
    Red is much more tenacious and using blue on tiny fasteners (especially if you do it right and use the primer / thread cleaner first) can make the purchase on tiny fasteners with blue on them very tenacious in deed. Not cleaning the threads and just putting blue on is kind of hit or miss as far as the loc strength you get due to varying amounts of oil on the fasteners from the maker.

    Best to use purple, prep the threads with the primer . . . then you KNOW what kind of loc you are going to get.

    Purple : think bubble gum.
    Blue : think fairly hard plastic molded into the threads.
    Red : think epoxy like bond (need to heat the fastener or beat on it to get it apart). The stuff is even fairly heat resistant !
    jpm2, kreisler and Night Rider like this.
  15. kreisler


    May 11, 2012
    Question. Once you've opened a factory-fresh 10ml bottle of (blue or purple) Loctite, for how many months (or years) after the official expiration date is the product still very usable for our knife purposes, from your experience? Storage conditions: tightly closed 380 lid, at room temperature. EAN 0893208001600
    Last edited: Nov 21, 2019
  16. soc_monki

    soc_monki Basic Member Basic Member

    Apr 5, 2019
    I use the blue stick. Less mess, works great. I only use it on pivot screws though, never had a problem with other screws backing out, but I do check them periodically.
    kreisler likes this.
  17. TheEdge01


    Apr 3, 2015
    I use blue and it always works.
    kreisler likes this.
  18. Chronovore

    Chronovore Basic Member Basic Member

    Aug 29, 2019
    I've never tried purple Loctite. Does it come in a stick?

    I just looked up "Purple Loctite Stick" on a major retail website and the result was Loctite Hi-Tack Stick Gasket Dressing. Is that the right stuff?
  19. rycen

    rycen Super Moderator Staff Member Super Mod

    Aug 22, 2002
    Not the same thing. It doesn’t appear as the purple version of the Loctite comes in a stick.
    kreisler likes this.
  20. kreisler


    May 11, 2012
    All good info in PDF format: http://dm.henkel-dam.com/is/content/henkel/threadlocker-user-guide (1)pdf

    That PDF explained in video format:

    Bottom line, tomorrow i am going to buy 10ml of purple. Local dealer sells for less than 13eur oic.
    ( EDIT: i've bought it, unsealed the tip dispenser, and applied the purple stuff on the T9 pivot screw of my eol Enlan. the stuff is as liquid as water wtf, very very low viscosity, "10ml = 11g" i'm shook! i'll let it cure for 2 days np. then i'll try to disassemble the pivot screw again. btw when i disassembled the pivot screw i could tell that there was purple (well, at least not blue or red!) cr*p in the female and male threadings. apparently the Enlan factory uses screw fastening substance too! i'll report back again in a few days. btw the dealer had all kinds of loctite, e.g. the blue stick. )
    Last edited: Nov 26, 2019

Share This Page