Blue Loctite Or No ?

[naimad]

https://www.vibra-tite.com/industries/firearms/

[ocabj]

[Carcassonne]

Im curious about the purple loctite

A mix of red and blue.

http://henkeladhesivesna.com/blog/the-difference-between-red-blue-green-and-purple-threadlockers/

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[Carcassonne]

Just curious but did you use a torque wrench when installing the rings?

Yes, but I used a better torque wrench the second time.

Anti-seize on the threads the first time may have played a part. It is possible that it caused a false torque reading.


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[Ki6vsm]

Just don't use the green "wicking" Loctite.

I found out how strong it is after I'd used it to better secure a gas block on a barrel. I figured it would be a good supplement to the set screws. Then six months later I decided I wanted to change the handguard/rail. So the gas block needed to come off. Let's just say it required a lot of heating with my MAP gas torch, plus poundings from a hammer! I basically ruined my gas block in the process and had to buy another one. So yeah that green stuff really wicks! And requires serious heat to break down again.

[Carcassonne]

Just don't use the green "wicking" Loctite.

I found out how strong it is after I'd used it to better secure a gas block on a barrel. I figured it would be a good supplement to the set screws. Then six months later I decided I wanted to change the handguard/rail. So the gas block needed to come off. Let's just say it required a lot of heating with my MAP gas torch, plus poundings from a hammer! I basically ruined my gas block in the process and had to buy another one. So yeah that green stuff really wicks! And requires serious heat to break down again.

Green is used for electronics screws. If you look at older PC boards you will probably see some green stuff around the screws. It is supposed to resist vibration. I have never had problems removing green Loctited screws in electronics. Maybe the heat from the hot gasses caused the green Loctite to turn into super glue.





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[ocabj]

I use Loctite 290 (green) specifically for the A2 National Match front sight base. Once I get the windage zero set with the A2 NM FSB, I hit the set screws with Loctite 290, then the area where the barrel and FSB meet just to get some 'glue' between the two so it is set well (and even eliminate any minute gas bleed).

As far as getting it off, I haven't had trouble. Whenever I had to rebarrel, I just use a driver to get the set screws off, then a rubber mallet to break it loose from the barrel if needed.

[Ki6vsm]

I use Loctite 290 (green) specifically for the A2 National Match front sight base. Once I get the windage zero set with the A2 NM FSB, I hit the set screws with Loctite 290, then the area where the barrel and FSB meet just to get some 'glue' between the two so it is set well (and even eliminate any minute gas bleed).

As far as getting it off, I haven't had trouble. Whenever I had to rebarrel, I just use a driver to get the set screws off, then a rubber mallet to break it loose from the barrel if needed.

Man, that was NOT my experience at all. And I did exactly as you did: little bit on the set screws and a little bit at the front edge to wick under the base and help seal it up a little. I should post a picture of my deformed and discolored (from the torch) Troy gas block. I wouldn't say it's ruined. But it might take some filing to get a gas tube into it again. I will say though that it's probably easier to get a good strike angle on a FSB than it is a little low-pro gas block.

FWIW, I don't recall having any problem getting the set screws back out. But I think with screws there is a relatively small surface area involved, vs. the whole inside surface of a gas block. Lots more area to bind.

However, I might take back what I said earlier about not using it on optics screws. Obviously the the green wicking type is for use on fasteners etc. that have already been installed. So it might be a good thing to use if you mount your scope all nice and decide later you want to secure it better. Just don't overdue it and glue the scope to the rings. The stuff runs like light oil.

FYI, there is another kind of green Lockite that should probably be avoided altogether. It's the #660/680 types. Those are retaining compounds, used to glue bearing races in place and things like that. Very strong, long-term hold. I don't know if it has much application in the gun world.

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[Ki6vsm]

Update on the "green" issue. I just checked my toolbox and, technically, it was not Loctite 290 that I used. It was the Permatex equivalent. Their green "penetrating" thread locker. I can't say if P and LT are re-packagings of the exact same stuff. But this is the stuff that gave me all that grief:

[Horrendo Revolver]

I only use Loctite on base to receiver screws. Inch-pound torque wrench, driver, or limiters for everything.

This. Blue on base screws, nothing on ring screws.

[E92335i]

Blue on base.

[Ki6vsm]

FWIW, I just remembered that my Bobro mounts each came with a little dispenser of the purple thread locker. No base screws to deal with there, so we can assume they think we ought to use it on their rings.

[osis32]

I know some mounts and rings will void their warranty if you put thread locker on their products. adm is one such company.

http://www.americandefensemanufacturing.com/?page=article/read&id=265

[Ki6vsm]

I know some mounts and rings will void their warranty if you put thread locker on their products. adm is one such company.

http://www.americandefensemanufactur...le/read&id=265

The way I read it, it says to put Vibra-tite thread locker on the threads, but it voids the warranty if you use Loctite. Seems weird since they're so similar, and there are so many types of both. And "...will damage the threads..."? I'm nonplussed.

https://www.vibra-tite.com/threadlockers-comparison-table/

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