Info on thread locker, torque specs

[cpd2110]

Disregard, I missed the best practices thread at the top of the forum. Please delete this thread moderator.

My agency is wading into the RDS program cautiously. As part of that we are running a trial program for firearms instructors for approximately a year. We hosted Aaron Cowan recently and learned a lot. The one question I asked and Aaron gave his thoughts was if there was a go-to location for finding what works best in this area in terms of what torque specs work best, what thread locker etc. We had our best guy, in terms of mechanical ability, build all of our guns for this class. They are a mix of Glock 17/19's Gen 5 Mos, with CHPWs plates torqued to their spec's. We had three plates come loose. Aaron had a toque spec of 18inch lbs, while our researched said 12-13inch lbs for holding the plates down. There could be lots of reasons these came loose and I am not finding fault with any person or company. The original toque wrench didn't seem very exact and maybe gave a false reading. Possibly the thread locker wasn't dry at application but my guy believes it was. We shot a lot in a short amount of time. Aaron was impressed with the very little downtime, even during a crappy day of weather. So maybe a few guns got heated up and the locker came loose? I'm really looking for people who have high round counts and have come up with the best practices to ensure, the best you can, the units stay locked on the gun. This may have been covered other places and if so I apologize.

[RJ]

If Ok to ask, I’d like to know what y’all used for threadlocker?

[cpd2110]

If Ok to ask, I’d like to know what y’all used for threadlocker?

Vibratite VC-3. 3 of 7 came loose. We shot about 500 rounds per day.

[RJ]

Vibratite VC-3. 3 of 7 came loose. We shot about 500 rounds per day.

Thanks a bunch.

[Super77]

I have used vibratight as included with 3rd party optics plates and torqued to spec according to mfgr white sheet (calibrated wiha torque driver) on three separate installs and all three came loose. I then went back to good ol blue loctite and torqued to German spec (i.e. goodentight) and no problems after about 3500 rounds/4 months.

[farscott]

After reviewing the Vibra-Tite VC-3 data sheet, there is no way I would use the product. The data sheet has no discussion on torque strength per ISO 10964, no data on strength, and vague instructions on amounts to be used. When it comes to thread lockers, my default is Henkel (maker of Loctite) where selections can be made based on screw and substrate material, fastener size, and application.

[guymontag]

Interesting on the recommendations - I’ve been using blue loctite and hand tight and even Burris red dots with little problem so maybe it was luck the whole time. A few thousand rounds (and quite a few hours of dry fire) through mounting on two different pistols though - I’m not a PD or a custom shop.

[stomridertx]

I think there was another thread also where blue Loctite was emerging as the winner here. I've never used Vibratite, but blue Loctite 243 has never failed me on scope mounts or my MOS plate mounted RDS. I'm about to go to the CHPWS plate. One thing I did do that may or may not be a necessity is replace the screws that came with the MOS plate package with McMaster-Carr Torx screws. So much is depending on the strength of the fasteners themselves that I felt better knowing exactly where they were sourced and what the specs are. I do torque to spec with a FAT wrench and I believe I used 15 inch lbs.

[RJ]

I think there was another thread also where blue Loctite was emerging as the winner here. I've never used Vibratite, but blue Loctite 242 has never failed me on scope mounts or my MOS plate mounted RDS. I'm about to go to the CHPWS plate. One thing I did do that may or may not be a necessity is replace the screws that came with the MOS plate package with McMaster-Carr Torx screws. So much is depending on the strength of the fasteners themselves that I felt better knowing exactly where they were sourced and what the specs are. I do torque to spec with a FAT wrench and I believe I used 15 inch lbs.

We have been around this bush before:

https://pistol-forum.com/showthread.php?44048-Vibra-Tite&highlight=vibra-tite

[RJ]

After reviewing the Vibra-Tite VC-3 data sheet, there is no way I would use the product. The data sheet has no discussion on torque strength per ISO 10964, no data on strength, and vague instructions on amounts to be used. When it comes to thread lockers, my default is Henkel (maker of Loctite) where selections can be made based on screw and substrate material, fastener size, and application.

farscott, I'd be interested in your thoughts. I contacted Henkel directly and asked for guidance on small screw applications such as pistol optics. I never got a reply. Using their decision tree, it seems that for fasteners below 1/4" (6mm), they only recommend purple/low strength. I've never heard of anyone using purple, just blue.

Any thoughts on purple vs. blue?

69586

Based on threads like this one, and the one I quoted, I just have been using blue/medium strength; no issues so far. So for me, it's kind of an academic question, but I am curious what you think.

[RJ]

I think there was another thread also where blue Loctite was emerging as the winner here. I've never used Vibratite, but blue Loctite 242 has never failed me on scope mounts or my MOS plate mounted RDS. I'm about to go to the CHPWS plate. One thing I did do that may or may not be a necessity is replace the screws that came with the MOS plate package with McMaster-Carr Torx screws. So much is depending on the strength of the fasteners themselves that I felt better knowing exactly where they were sourced and what the specs are. I do torque to spec with a FAT wrench and I believe I used 15 inch lbs.

If you are going with the V4 Defender all-polymer plate, don't do what I did: I did not connect the dots on the "Special" instructions for the polymer plate. You are specifically directed NOT to torque to spec (in lbs) for this plate. I was all set with my slide and had the (wrong) instructions up on the screen, direct from CHPWS. I proceeded to set my Wheeler to the specified amount (for non-polymer plates) and promptly drove the screws all the way into the plate, deforming the chamfer completely. Thus completely blowing $70 down the drain. My bad.

After this experience, I ordered a steel Forward Controls plate, and have been completely satisfied with it.

[farscott]

I like Loctite 243 because it works on plated metals and in the presence of lubricants. It cures better in higher temperatures and without using the curing accelerator.

[stomridertx]

If you are going with the V4 Defender all-polymer plate, don't do what I did: I did not connect the dots on the "Special" instructions for the polymer plate. You are specifically directed NOT to torque to spec (in lbs) for this plate. I was all set with my slide and had the (wrong) instructions up on the screen, direct from CHPWS. I proceeded to set my Wheeler to the specified amount (for non-polymer plates) and promptly drove the screws all the way into the plate, deforming the chamfer completely. Thus completely blowing $70 down the drain. My bad.

After this experience, I ordered a steel Forward Controls plate, and have been completely satisfied with it.

Good to know. I'm actually going with what they call the Mil/LEO aluminum plate for the RMR, because I'm evaluating the the Swampfox Liberty and want to get out of the stock MOS plate sooner than later regardless of which optic finds it's permanent home on there.

[stomridertx]

We have been around this bush before:

https://pistol-forum.com/showthread.php?44048-Vibra-Tite&highlight=vibra-tite

It was actually nice to revisit that thread and read comments I haven't seen yet. I want to try the blue stick Loctite 248 now as it looks a lot easier to work with on firearms and scopes.

[Steve m]

I believe that in a You-Tube Video, CHWPS recommends 10in lbs of torgue, if using their plates. I have X3 plates and that is what I use with blue loctite and no issues so far.

[EzGoingKev]

I have been using the purple loctite for 25 years. It has always worked as advertised and I have never had a problem.

I use on my Glock's front sight screw and on my RMR related hardware.

[OlongJohnson]

I have purple, blue, red and green (290 wicking, not the sleeve compound) on my bench and use them all as called for.

One thing to be mindful of is that Loctite can cause many polymers to crack/fracture, so be careful using it around them.

[Archer1440]

Here we go again. There is one answer, and it is simple.

[SoCalDep]

Here we go again. There is one answer, and it is simple.

Preach!

i may know a little about high round counts and heat. I may have supervised 1,985 rounds fired through an optic-equipped pistol in 25 minutes. I have seen VC-3 be successful in a 10,000 round test. I won’t use it on any of my guns or any gun on which I mount an optic for my guys. Loctite 248 is the way.

There is a lot of voodoo and a lack of understanding of threaded fastener engineering going into pistol optics right now in many circles. I have learned a lot from this forum and in consultation with smart people and from what I’ve seen with VC-3, if not applied perfectly it has the opposite effect under slide reciprocation than intended. Loctite is better and 248 allows the right amount to be placed in the right spot. I use it on my (and my Department’s) 6-32, M3, and 4-40 screws on a lot of guns with a lot of optics and have had few issues compared to the VC-3.

[BWT]

farscott, I'd be interested in your thoughts. I contacted Henkel directly and asked for guidance on small screw applications such as pistol optics. I never got a reply. Using their decision tree, it seems that for fasteners below 1/4" (6mm), they only recommend purple/low strength. I've never heard of anyone using purple, just blue.

Any thoughts on purple vs. blue?

69586

Based on threads like this one, and the one I quoted, I just have been using blue/medium strength; no issues so far. So for me, it's kind of an academic question, but I am curious what you think.

I use blue loctite as a thread locker except Glock front sight posts given the amount of heat they are exposed to.