Loc-Tite Questions

[Flynt]

Last night, I noticed that the bolt behind the trigger guard assembly had fallen out of my Sako Hunter 75. Luckily, I didn't lose it, and I screwed it back in as tight as I could. Is this a candidate for Loc-Tite? I've got the red, but as I understand it, it's pretty permanent. Would I permanently attach the bolt so that no one could remove it? Thanks.

 

[USSR]

Flynt,

DO NOT loctite your receiver bolts. Check them prior to any shooting session and tighten as necessary.

Don

 

[MikeIsaj]

Not a gunsmith but here's my thought anyway. My basic understanding of mechanics tells me that there are several reasons screws come loose.
1. The torque isn't sufficient (not tight enough)
2. The torque is too great (Too tight? My nephew the machinist says it's possible. Something about torsion stress, kinetic energy and action-reaction...)
3. The screw is a fraction too small. (normal wear or manufacturing defect)
4. The hole is too large.

2 & 4 are unlikely longshots. 1 is corrected by tightening it up. If it continues to come loose, I'd replace the screw.

 

[Sleeping Dog]

I like USSR's answer. Check and tighten.

I use loctite on some screws, like the ones that hold the weaver rail to the receiver. But I always use the blue loctite - it's weaker, no need to use heat to remove the screws. It seems more useful in more applications than the red stuff.

Regards.

 

[JoeHatley]

Use the removable blue #242.

Joe

 

[Rockstar]

I've never used Loctite on action screws, but I do use a torque wrench to tighten them. I don't see any harm in using 242(blue) Loctite, though. How could the Loctite possible adversely affect anything?

 

[scott.cr]

Others have indicated that loose screws (in the GUN) are an indication of a problem. This is probably 99% correct. Most of the time, a screw that's been removed/installed often or simply over-tightened sometime in its past will be stretched. And when screws stretch, their OD gets smaller, which allows them to loosen. (That and the altered elasticity of the screw.)

I would use any type of thread locker as a last resort. Try a new screw first if you can find one, and be careful not to over-tighten it.

 

[Hawken50]

you could put a couple wraps of teflon tape around the threads. it will keep it from vibrating out and you don't have to worry about it being perminant

 

[Flynt]

Hweken, thanks for the tip. Is teflon tape the same stuff that you use to wrap threaded pipe fittings?

 

[brickeyee]

The correct grade of loctite is not permanent either.
Without some type of locking mechanism (mechanical or other) fasteners come loose under vibration and cyclic loading. There is nothing wrong with using loctite to stop this movement.
Self locking screws come in a number of styles, from small patches of locking compound, nylon inserts, or even deformed threads. Aircraft use them all the time. Compound must be replaced, nylon inserts wear out, and deformed threads are technically a single use.
For really important things you get out the cotter pins or wire to lock the fasteners.

 

[Hawken50]

Is teflon tape the same stuff that you use to wrap threaded pipe fittings?

Yep, that's the stuff.