Which Thread Locker?

[DanGee]

I recently installed a Burris Fastfire 3 on my 3-5-7 range gun. It only took three cylinders worth of shooting to dial in, but then another two cylinders loosened the mounting screws so that my groups became a pattern. What do you guys use to ensure the screws back out? I see there are several grades of Locktite.

 

[lkabug]

Check out the Loctite website. You probably want to use Loctite Threadlocker blue.

 

[RGPM1A]

I always use Blue for this.

 

[Protocall_Design]

I have used the blue #242 medium strength for years with good results. The blue is now called grd. C. Blue #243 can be harder to deal with than #242.

I have lately gone to purple #222 low strength, now called grd. H. It seems to be a lower viscosity and fills in the voids a little better. So far, it is working as well or better than the blue.

Either one will do a fine job of holding the parts in place while allowing for adjustments or removal without using any heat. You need to clean the male and female threads with solvent, make sure the solvent evaporates or is otherwise gone, and coat the threads with Loctite, assemble and wipe off any excess. A Q-tip is handy for cleanup operations.

 

[chief38]

Here are the 3 main Loctite colors:

Purple (#222) low strength
Blue (#243) Medium strength
Red (#262) high strength

The medium should be more than enough, I rarely use the Red (permanent) which is a bear to loosen without heat. I also rarely use the purple but will when I routinely disassemble something and don't want to fight with it. The Blue is a mainstay.

I'd make sure you clean the parts with Acetone or Alcohol before you apply the Loctite. Also shake the bottle before using.

 

[jbtrucker]

I clean the threads with a cue tip , alcohol and then Blue Locktite

 

[Igiveup]

I have found that the blue Locktite works fine with any site application and for receiver screws. I have grandsons that seem to relish in loosening the receiver screws and then running to me to declare the scope is off.

 

[CH4]

Another vote for blue 242

 

[Benchrest1]

I've had good luck with blue.

 

[Greyman50]

Many years around machine tools, nearly every mfg. back in the day used either blue for normal thread locking and alway Red for never removed. My 25-2 had a buggered up ejector rod since the previous owner could not figure left hand threads, had to replace outer rod, used Blue to secure new. Make sure to remove all oil, clean with acetone or similar before using Loc Tite.

 

[Rolex28]

Read an article the other day.. Blue works for most applications, BUT if you are planning on shooting many rounds especially in competitions, Red is best especially on front sites where it will get very warm..

 

[stu1ritter]

Purple #222 is for threads up to 1/4" in diameter and blue is for threads from 1/4" to 3/4" in diameter (Loctite literature). Purple seems to fit for scope mounting screws.

Stu

 

[Jaco1234]

I have used locktite products and think they are great and still use them.
Recently I read an ad for Vibra-tite. VC-3. This is a thread locker that remains pliable and adjustable while locking the thread. I have used it on a couple of fire arm applications and it works well. it is adjustable and removable up to 5 times.


Remember that locktite hardens by removal of oxygen. Thats why the bottles are only half full. One mechanic I know decided to combine the partial bottles he had into i bottle. Now he has a full to the brim bottle of solid locktite.

 

[Krogen]

Purple (#222) works for me on gun screws. I haven't found a need for anything stronger and the screws can be easily removed if need be. It's not like any strength is needed, I just want an anti-rotation material.

 

[Doug M.]

I think the install I had done professionally was done with red. It was a REAL HARD JOB to get th screws out when I changed RDS. Took a lot of heat.

 

[Old cop]

Very timely b/c I just picked up the blue lock tight for the cylinder release latch screw on my 340PD.

 

[AJR337]

I recently switched to 243 Blue for any firearm related uses, which is an upgraded version of 242 with "improved oil tolerance".

 

[wagwan]

There is also locktite green which is applied after the screw is in place. It is primarily used for set screws but could work here, too.

 

[pantannojack]

I had stuck screws on a pre64 M70 when I installed new Leup rings. I cleaned the holes and screws with degreaser and hand torqued them down. I could not make them break loose for 15 years, until some heat and a hammer tap. I will not do that again.

 

[stu1ritter]

There is also locktite green which is applied after the screw is in place. It is primarily used for set screws but could work here, too.

You really don't want to use the wicking green Loctite as it is Medium/High strength and takes heat to take apart.

Stu