Loctite issues possible?

The #1 community for Gun Owners in Indiana

Member Benefits:

  • Fewer Ads!
  • Discuss all aspects of firearm ownership
  • Discuss anti-gun legislation
  • Buy, sell, and trade in the classified section
  • Chat with Local gun shops, ranges, trainers & other businesses
  • Discover free outdoor shooting areas
  • View up to date on firearm-related events
  • Share photos & video with other members
  • ...and so much more!
  • halfmileharry

    Grandmaster
    Rating - 100%
    65   0   0
    Dec 2, 2010
    11,450
    99
    South of Indy
    My last few trips to the range have me finding some problems with screws backing out EVEN AFTER being loc tite treated.
    I am using the Permatex Thread Lock 24200. Blue, medium.
    All problems are with AR optics and mounts. Shooting 55gr fmj Federal premium and 62 gr M855.
    American Defense mount on my Aimpoint Comp M3 backed off on my LE6920 this morning.
    Yesterday it was a Millett 4 screw ring mount system. Never had problems with them before going to the Permatex brand.
    I use NON-residue grease and wax remover and blow off the excess before using. I am letting them sit for at least 24 hours before using the rifles.
    Suggestions? Thoughts? I'm getting a bit frustrated at this point.
     

    Mr. Habib

    Master
    Rating - 0%
    0   0   0
    Mar 4, 2009
    3,781
    149
    Somewhere else
    The purple Loctite has a lower yield torque than the blue does, I don't think that's what you want. Check the expiration date on your bottle, it can go bad. Are both the mounts and rail MIL 1913 or are the mounts Weaver style? I have seen the same thing happen with a Weaver mount on a Picatinny rail. The cross bolts aren't the same size and the slots are different widths. You can't that combination tight enough to not move sometimes.
     

    1911ly

    Grandmaster
    Site Supporter
    Rating - 100%
    6   0   0
    Dec 11, 2011
    13,419
    83
    South Bend
    If your threads have came loose to many times they might just be worn. You can step up to the red But you will mostlikely need heat to remove the screws. I use a soldering iron, but you have to be careful what you put it on.

    Mr H's comment is probably spot on, maybe old.

    Are you shaking your bottle before applying??
     

    Mr. Habib

    Master
    Rating - 0%
    0   0   0
    Mar 4, 2009
    3,781
    149
    Somewhere else
    The blue stuff should be plenty strong. I have snapped Allen wrenches in two trying to break loose screws with blue Loctite. If that isn't working, your issue most likely lies elsewhere.
     

    churchmouse

    I still care....Really
    Emeritus
    Rating - 100%
    187   0   0
    Dec 7, 2011
    191,809
    152
    Speedway area
    Clean the threads in the gun and on the screws completely. No oils present. Inspect the threads.
    If blue does not hold them there may be another issue.
     

    halfmileharry

    Grandmaster
    Rating - 100%
    65   0   0
    Dec 2, 2010
    11,450
    99
    South of Indy
    Both mounts are in excellent shape. No stripping or loose tolerances on either.
    This is the first Permatex I have used. They were out of the LocTite brand so I went to the auto parts store for this. It's fresh new packaging. I shook it well. The Permatex seems thin and watery compared to the LocTite.
    I have been making it a priority to practice in this cold weather. I was wondering about the metals contracting at different rates in this cold.
    EDIT:
    I do clean the threads very well to remove any oils or contaminants with a good non residue cleaner I've been using for over a decade. I know it's good in that aspect.
     

    Drail

    Master
    Rating - 0%
    0   0   0
    Oct 13, 2008
    2,542
    48
    Bloomington
    It is most likely the use of "non residue cleaner" is the problem. You don't want a "cleaner" - you need a powerful solvent. Use acetone. Nothing does a better job of removing EVERYTHING - it will melt most plastics - be careful with it. Use red Loctite. I have used this method for 30 years and it's never failed.
     

    halfmileharry

    Grandmaster
    Rating - 100%
    65   0   0
    Dec 2, 2010
    11,450
    99
    South of Indy
    It is most likely the use of "non residue cleaner" is the problem. You don't want a "cleaner" - you need a powerful solvent. Use acetone. Nothing does a better job of removing EVERYTHING - it will melt most plastics - be careful with it. Use red Loctite. I have used this method for 30 years and it's never failed.

    I've been using this same method for a heck of a long time and the only variable I have done is the Permatex instead of LocTite.
    This is a solvent/cleaner that leaves NO residue.
    The cold weather is the only other variable.
     

    t-squared

    Master
    Site Supporter
    Rating - 100%
    7   0   0
    May 9, 2012
    1,765
    113
    Crown Point
    I bought some cheap "no name" blue loctite from Harbor Freight once and found that it didn't do nearly as good a job as the real stuff. Maybe the Permatex stuff isn't as good as LokTite brand...or you got a bad batch..???
     

    Hookeye

    Grandmaster
    Rating - 100%
    4   0   0
    Dec 19, 2011
    15,039
    77
    armpit of the midwest
    Crowd your mount's crossbolts to the muzzle side of the slot and then tighten.
    I've done that and my mounts/rings on Weaver bases and flattops have stayed solid (no Loctite).
     

    Hookeye

    Grandmaster
    Rating - 100%
    4   0   0
    Dec 19, 2011
    15,039
    77
    armpit of the midwest
    Cleaner/solvent leaves no residue............that might be false advertising.
    Bad batch of thread locker could be additional problem.

    Gunscrubber and then real Blue Loctite, new batch.
    If things are problematic after that (proper torque) then you probably have something mechanical out of spec.

    Gotta crowd the crossbolts to the front of the slots though, no matter what.
     

    johnb62

    Master
    Rating - 100%
    48   0   0
    Oct 15, 2008
    3,466
    84
    Evansville Area
    Having used all types of Loctite in an industrial environment, I can only echo what has been previously mentioned. Clean, residue free surfaces are the key. Be careful with red. It can be a bear if you want to disassemble.
     

    halfmileharry

    Grandmaster
    Rating - 100%
    65   0   0
    Dec 2, 2010
    11,450
    99
    South of Indy
    Problem found.
    I bought some LocTite brand blue yesterday and redid my rings and bases in it. The Permatex still hadn't set up on the screws.
    I cut open the tubes (2) of the Permatex and it was rock hard in the bottom and runny on the top. It had separated. Old? Maybe? I'm not sure. I do know that the compound wasn't working.
    I went out a few hours ago and re-sighted in my Comp M3 and 4x Leupold. I checked the screws before going out and they were snug and proper.
    I guess I got some old stock Permatex or some that had been frozen? Maybe? Not sure.
     

    Grelber

    Master
    Rating - 100%
    17   0   0
    Jan 7, 2012
    3,479
    48
    Southern Indiana
    Loctite brand has never let me down so I spend for the name, of note, 243 blue is the new and improved 242 (better tolerance of some contamination on the threads is the main difference I think).

    Probably still a very good idea to keep it somewhat fresh & shake the container though.
     

    calcot7

    Master
    Rating - 100%
    11   0   0
    Dec 12, 2008
    2,571
    38
    Indy N Side
    I have also had problems with the "permatex" brand not performing as I expected it to. It is thinner (Runny) and has not held the screws on the last couple of projects I have used it on.
     
    Top Bottom