blue Loctite not working to hold torque

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.
Total agreement that surface prep/cleaning is VERY important! Heck, for years I've used white school glue on everything, including 2 - .45-70's & never had a problem, (except on scopes I never glued). Works for me & fairly easy to break.
 
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.
Mines a heavy tangent theta scope but the total weight is 25 pounds because I added weight to the chassis so that will reduce the impact force the scope mount and rail will see. I shoot 300 norma mag and I can shoot all day comfortably
 
How important is it for the threads to be oil-free before using blue Loctite? I'm shooting .300 Norma mag and the pic rail mounted directly to the Stiller action comes loose after every 150 rounds or so. What should I do? How do I get the oil off the threads? I tried alcohol before but the threads end in a wall so I can't be sure I've got all the oil out.
Getting it completely oil free and dry is very important. Whatever you do, don't use red loctite.

Make sure it's shook up good before applying and be sure every bit of oil is removed.

You can actually dip the screws in blue repeatedly letting them dry and then screw them in and it will give you a really good bond that way as well.
 
I would bed the rail to the action sans release agent. It will never move again. If you want it off just use a heat gun to heat the rail up and it will come off.
A less permanent solution is to just take it to a gunsmith and have a couple of pin put in. I've bedded some and that works great but on the off chance you sell it or want to switch to something else it's a whole lot simpler process.
 
that'll be Plan B if red loctite and brake cleaner don't work
Red locktite takes a lot of heat to soften if you ever want to remove those screws if done right.

No bonding agent though is going to work well unless it's absolutely clean and oil free both on the screws and in the screw holes.
 
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As was pointed out earlier in this thread, some of the Blues are more tolerant of oil than others. However, none of them will work in a truly oily environment.

Some solvents leave behind trace coatings that may or may not inhibit the effectiveness of a thread-locker. That is why I prefer those that evaporate like aerosol brake cleaner and gun scrubber because they will take with them almost everything when they go.
 
Bedding a rail with epoxy would help - increase surface contact area. The epoxy might also provide a shoulder or surface attached to the rail that would prevent apparent forward movement of scope & rings upon recoil. Variations of receiver dimensions might cause gaps between machined rail shoulders & receiver edges. I have had stuck hex head screws using blue thread locker & only use Torx screws.
 
Get some engine starting fluid. It degreases everything and leaves the surface residue free.
Lol 100% evaporation just don't huff it. When you re-zero verify it at night. Just put a road flare upright behind it and center punch the can. Works way better than those small propane cans.
 
How important is it for the threads to be oil-free before using blue Loctite? I'm shooting .300 Norma mag and the pic rail mounted directly to the Stiller action comes loose after every 150 rounds or so. What should I do? How do I get the oil off the threads? I tried alcohol before but the threads end in a wall so I can't be sure I've got all the oil out.
To get the best adhesion the threads need to be oil free. How one gets the screw holes and screws oil free is often a matter of preference. I use lacquer thinner. I dip a pointed Q tip that women use for cosmetics and screw it into the screw hole several times using clean Q tips each time. Once the hole is clean clean the screws simply by dropping them into a small container (A bottle cap works fine since the screws are not big) E of either cleaning agent. Wipe them clean with absorbent facial tissue and now you are ready to use them to mount your scope. I use both LocTite 242 and 270. dependent on what caliber rifle I am mounting the scope on. 242 works good on the lighter recoil rifles, up to .308. 30-06 and above I use Red 270. The 270 is more of a permanent type of LocTite however if you ever have to remove the screws simply heat up the mount area with either a hair dryer or heat gun. You do not have to get LocTite 270 very hot before it softens and allows for easy removal. Make sure when you are mounting the rings to the rail that you have them pressed firmly to the front of the slot before torquing so they don't move under recoil.
 

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I use electrical contact cleaner in a spray can. A little less aggressive than brake cleaner or carb cleaner and generally more compatible with finishes and plastics. If it is safe for a circuit board it is generally ok for firearms. I use it for ARs, pistols, revolvers, everything. Extension tube makes it great for blast cleaning 22 actions of all that gunk, even if the frame and/or parts are plastic and nylon. Works great for threadlocker prep.
 
I agree with what is mentioned above in regards to bedding the rail to the action. One thing you could do is lap the rail to the action. One way to do this without marring the action is to place a piece of 1000 grit sandpaper on the action and slide the rail back and forth. You will then see if there are any high spots on the rail preventing good mating with the action. Just make sure to tape off the action fist to prevent any grit from the sandpaper getting into the action. I like to use Devcon Steel Putty for bedding metal to metal.
 
I use electrical contact cleaner in a spray can. A little less aggressive than brake cleaner or carb cleaner and generally more compatible with finishes and plastics. If it is safe for a circuit board it is generally ok for firearms. I use it for ARs, pistols, revolvers, everything. Extension tube makes it great for blast cleaning 22 actions of all that gunk, even if the frame and/or parts are plastic and nylon. Works great for threadlocker prep.
I'll have to remember that, thanks.
 
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