Proper Use of Threadlockers Such as Loctite on Your Pistol

[Alllen Bundy]

I highly recommend that you read this guide before using a threadlocker on your pistol, automobile, or whatever.

Threadlocking User’s Guide
https://dm.henkel-dam.com/is/content/henkel/MRO_TL_Guide

The most common mistake that I see is people making is using a threadlocker with inactive metals such as:

Plated Parts
Anodized Aluminum
Titanium
Stainless Steel
Galvanized Steel
Zinc
Pure Aluminum
Cadmium
Magnesium
Natural or Chemical Black Oxide
Magnetite Steel
InconelTM
Silver
Gold

Loctite requires not only the absence of air to cure, but it also requires that at least one surface is an active metal that will trigger the curing such as:

Iron
Plain Steel
Copper
Brass
Bronze
Manganese
Monel
Kovar

If at least one surface is not an active metal, you must either use a primer on the metal before applying the Loctite, or you must use one of the new Loctite formulations that have a built in primer.

I bought an aftermarket return spring assembly with a stainless steel guide rod and an black oxide coated threaded end. I was able to unscrew the end WITH MY FINGERS and they had used a high strength thread locker! Other people reported that the guide rod unscrewed while they were shooting.

To be sure that it wasn't a bad batch of thread locker or dirty parts at the factory, I thoroughly cleaned the threads with 99.99% isopropyl alcohol and used some fresh Loctite that I knew was good and I had the same poor results.

I bought a tube of the new Loctite #243 blue medium strength formulation that had the primer inside. I applied a drop to the threads and it locked up solid. There was no need whatsoever for the high strength Loctite. The medium strength Loctite was more than adequate when it cured properly.

Sometimes you can get plated or oxide coated surfaces to cure Loctite. But that only happens if you are lucky enough to have enough of the oxide or plating scraped off so that the underlying active metal can cure the Loctite.

 

[Reinz]

Thanks!

 

[Dustbowl]

I’ve used nail polish for years. When it hardens it keeps the screw in place but will break loose without a huge amount of force.

 

[drband]

I wish I knew what to use on a Novak adjustable rear sight that keeps coming loose. If I use Loctite 243 on it, then have to make sight adjustments later, where does that leave me? Back at Square 1? Is there something other than Loctite that would make the adjustment screw "gummy," but wouldn't disappear with normal gun cleaning?

Vibra-Tite VC-3
Vibra-TITE 213 VC-3 Threadmate Threadlocker, -65 to 165 Degree F, 5mL Tube, Red
https://www.walmart.com/ip/396624718

it’s superior to loctite for your intended use. Just be sure to clean the threads well. It’s reusable (can be disassembled and reassembled a time or two) and holds firm every time.

I would avoid getting solvents on it. No threadlocker will stand up to a lot of solvent.

 

[Alllen Bundy]

Is there something other than Loctite that would make the adjustment screw "gummy," but wouldn't disappear with normal gun cleaning?

I haven't tried Vibra-Tite VC-3 yet. It has a more limited temperature range of -65°F to 165°F. Have any of you shot an autoloader enough to get the slide over 165°F? I believe that you can use MEK (Methyl Ethyl Ketone) to dissolve it.

Loctite 222 is a low strength threadlocker designed for adjusting screws and the like. It has an operating range of -65°F to 300°F. But after adjustment it must be reapplied.

FYI, I do NOT recommend using high strength red Loctite on gun sights as some people have recommended. It requires heat of 450° for 5 minutes to break it down so that you can remove the part, and it must be removed while the Loctite is hot.

 

[doubleh]

I’ve used nail polish for years. When it hardens it keeps the screw in place but will break loose without a huge amount of force.

I have used it since long before loctite ever hit the market. I haven't found a gun screw to this day that it won't hold.

 

[Rule3]

Never knew anything about the different metals and if it will work. Gads have to go to school to get the correct one!

 

[lysanderxiii]

Thread locker?

Never needed it on a pistol . . .

 

[Alllen Bundy]

Thread locker?

Never needed it on a pistol . . .

FYI, threadlockers are used on some return spring assemblies. Some people may use Loctite to keep optics screws from coming loose. Some people use Loctite on gun sights. Basically, Loctite can be used on any screw that you do not want to come loose. There was a recent video where someone was demonstrating a gun and a screw fell out onto the ground and got lost rendering the gun useless.

FYI, most screws that come loose are the result of poor design where the threaded fastener is loaded sideways instead of in pure tension. If you do not want a screw to come loose it should never be used as a locating device because side loading can cause the screw to come loose.

So what to many designers do? Use screws as locating devices, or otherwise side loading the bolt causing the bolt to come loose!!!! When you side load a bolt (Single shear configuration) you also need to make the bolt much heavier than if the bolt is used in pure tension. Loctite is the Band-aid fix for poor mechanical design.

 

[wild willy]

The only negative with the vibra-tite is it will harden in the tube once opened.It doesn’t really get hard but gets so thick you can’t use it.

 

[drband]

The only negative with the vibra-tite is it will harden in the tube once opened.It doesn’t really get hard but gets so thick you can’t use it.

Agree. The tubes are almost single use.
I bought a 30ml bottle which seems to store just fine. I’ve had mine 2+ years using occasionally.

 

[someguy2800]

Just get 243 or 263. They will set in just about anything, even plastic.

 

[jeepnik]

Simple solution is to never use loctite on a firearm. Or anything else you ever intend to disassemble again.

 

[Walkalong]

Most Loctite can be disassembled, although some needs heat, the most often made mistake is using too much.

Read the directions and use the right one, but Loctite has its place.

 

[Double_J]

We use locktite and vibra tite every day at my job, and our hardware is almost all 4-40 or smaller and exclusively stainless. We use a small amount per screw and make sure they are CLEAN and properly prepared. You can remove it with heat, and a small soldering iron is often enough for those screws.

 

[lysanderxiii]

FYI, threadlockers are used on some return spring assemblies. Some people may use Loctite to keep optics screws from coming loose. Some people use Loctite on gun sights. Basically, Loctite can be used on any screw that you do not want to come loose. There was a recent video where someone was demonstrating a gun and a screw fell out onto the ground and got lost rendering the gun useless.

FYI, most screws that come loose are the result of poor design where the threaded fastener is loaded sideways instead of in pure tension. If you do not want a screw to come loose it should never be used as a locating device because side loading can cause the screw to come loose.

So what to many designers do? Use screws as locating devices, or otherwise side loading the bolt causing the bold to come loose!!!! When you side load a bolt (Single shear configuration) you also need to make the bolt much heavier than if the bolt is used in pure tension. Loctite is the Band-aid fix for poor mechanical design.

I know what thread lockers are for . . .

It is just that on most of my go-to pistols the only threaded fasteners are for the grip panels. And some, don't have any.

If you do not want a screw to come loose it should never be used as a locating device because side loading can cause the screw to come loose.

Very true.

 

[Alllen Bundy]

I plan to replace my pistol sights in the near future. I'm not sure yet whether I'll use low strength wicking Loctite or Vibra-Tite VC-3 to secure the sights. Vibra-Tite VC-3 uses MEK as a solvent. I suspect that I could thin it out so that it could wick into the dovetail joint.

You could probably use some MEK to revive old Vibra-Tite that has thickened too much.

 

[Mot45acp]

Teflon tape.

 

[drband]

Reading on the vibratite web site, I found that the cured product is resistant to most solvents. FYI

 

[Otto]

The only negative with the vibra-tite is it will harden in the tube once opened.It doesn’t really get hard but gets so thick you can’t use it.

Loctite has a shelf-life of 24 months from date of manufacture. 12 months after opening.
Using old Loctite is a common mistake folks make. Same goes for Super Glue.

 

[Ethan Verity]

I personally prefer proper torque, rather than relying on the blue goop. I always use a torque screwdriver when reassembling gun screws, and have established my own torque specs for all my revolver screws which I've found to be safe for the threads, but prevents screws from coming loose over time. In many cases for optics/attachments mounting screws, a company will specify their own torque specs. For example, Magpul writes out their in/lbs specs as 30 in/lbs for metal/metal attachments, or 15 in/lbs metal/polymer.

 

[Alllen Bundy]

I personally prefer proper torque, rather than relying on the blue goop.

Torque specs will do very little to prevent a screw from coming loose if it is side loaded in a single shear configuration. It's not a question of whether or not the bolt will come loose, but a matter of when. You can use an oversize bolt and tighten it to an extreme amount and that will extend the time it takes before the bolt comes loose. And maybe that will be sufficient to last until other parts fail. But if there is any side loading involved a thread locker is advisable.

But you don't always have threads to secure the parts. A dovetail gunsight joint is a good example. Loctite make special formulations for sleeves and bearings which would work well on a dovetail joint. But it's still basically the same threadlocker. But I think that the sleeve and bearing retainers that Loctite makes are way to strong for a dovetail gunsight that you may need to remove intact.

 

[Alllen Bundy]

FYI, another huge advantage of using Loctite, or some other threadlocker or sealer, is that it prevents rusting.