blue Loctite not working to hold torque

Denatured alcohol or brake/parts cleaner and then compressed air work for me. If using brake cleaner make sure you have all other areas and materials removed (stock) as it can discolor or eat into plastic. Verify your threads are good on the screws and run a bottom tap in the holes. If you don't plan to remove the rail, you can go with a more permanent loctite as well. Also ensure you are torquing to specs. One other thing, shake the bottle of loctite for a coupel of minutes before you use it to get it mixed. Good luck.
I just ALWAYS swab them with alcohol.
 
Not sure if it was stated in replies to your question…..
Make sure your screws are not to long.
They should not be touching at the bottom of the hole- they may need to be ground a little shorter.
I can't tell you how many times I've seen this.
Alcohol, clean holes and screws, LocTite of your choice and proper torque,
 
I use Gun Scrubber or Brake Cleaner to de-grease both the hole and the screw threads.

On screws this small I don't feel that any of the Red's are a good choice. I use Blue. As it happens the Blue that I use is a thin, capillary action version because it is the biggest bottle on hand.

X2 on checking that the screws are just a little shorter than bottomed out.
 
He might try over-torquing... mating the threads together a little more, then backing off, then hit it with blue again, and re-torque them down.
 
Also, you might want to change out the screws. They could be starting to pull on the threads which give way for vibration to loosen the torque. Once the threads start to stretch they are not dependable, and loosen easily.
 
Denatured alcohol or brake/parts cleaner and then compressed air work for me. If using brake cleaner make sure you have all other areas and materials removed (stock) as it can discolor or eat into plastic. Verify your threads are good on the screws and run a bottom tap in the holes. If you don't plan to remove the rail, you can go with a more permanent loctite as well. Also ensure you are torquing to specs. One other thing, shake the bottle of loctite for a coupel of minutes before you use it to get it mixed. Good luck.
A Q-tip also gets in those tightest spots. Oil and lock-tite do not give the desired results. I worked in the defense industry and used both red and blue locktite. We were required to keep these refrigerated and near freezing until we used it, that bottle was discarded after use, it could not be put back in the fridge. I forget what our standard expiration date was but after it came up to room temperature we weren't allowed to keep it around for very long, maybe 10-14 days. Satellite assemblies had some rigid requirements.
 
Found out that red loctite is almost permanent. Had to have machinists drill out and re-tap the holes when trying to disassemble something we used the red on.
Always apply some heat to remove loctite

I use Red on the screws & green between the rail & action

Rails regularly come loose on Stillers esp with big scopes on them
 
I never use red, always blue. Degrease, let that dry, then apply blue to the screw and torque to spec. Let cure for 24 hours before shooting. Good tip about checking screw length before locking down. Red needs heat to be removable, use a soldering gun on the screw first, get it HOT.

I ran across one where the owner used super glue on the screws... Not good.
 
Loctite type products can behave strangely at times. The red shop rags we used years ago at one of my past employers had something in/on them that prevented Loctite from setting up. Took a while to figure that one out. Switched to different towels and problems went away. You can't get things too clean. The age of the Loctite doesn't seem to matter if stored in normal indoor temperatures.
 
I use carburetor cleaner. It's bad for stock finishes. I make sure each hole is real clean & clean the screws also. I use the carb cleaner outside.

I fear acetone because some guys I knew who used it freely in big amounts died early. If I had to use it inside, I would wear a cartridge respirator.

Extracting broken off screws involves drilling and use of screw extractors. Blue or medium strength thread locker works.

Wait 48 hours before shooting. Works on .300 WM & .375-.338 with heavy scopes & heavy steel rings.

Edited to provide clarity & focus.
 
Last edited:
Clean and oil free is very important. Loctite also sells a primer that works great to help it bond. The blue should be sufficient, I wouldn't use red. Loctite also has an expiration date. I haven't seen an issue, but according to one of their reps, it can make a difference.
 
For a heavy scope on a hard recoil rifle a good quality base rail should have a recoil shoulder machined on it that takes the recoil and holds position while the screws hold it down. You can dowel in the rail to accomplish this as well, the blue locate should work then. I strongly recommend bedding the mount with Devcon to fill gaps and help keep it in place regardless, and if possible up size the screws too. It is not fun to chase loose mounts.
 
Top