Is this carrier key leaking?

[MQ105]

I switched from Permatex to green Locktite (sleeve retainer) for carrier keys and find it works well. It hardens fairly quick once applied, so be ready...

[czgunner]

It seems to me an anaerobic sealant would be ideal.

https://www.permatex.com/products/ga...lange-sealant/

[Ned Christiansen]

This is a great thread.

Thanks for adding to the discussion Ned and Clint. I always enjoy your posts.

Ned, if you would join Facebook, you could help save more lost AR souls

Totally not gonna happen but with you there I think they can still be pulled from the fire and get the advice they need. In other words, glad to see you here.

I watched your carrier key swap / stake vid, good stuff and your modified staking screw profile has merit. We do things very similarly; when I'm doing a swap or restake it's usually one at time in more or less field conditions, but in the last year I've had occasion to do some small batches for people. That's where one starts trying to introduce more efficiency into everything which then makes for better processes back in the onsey-twosey scenario.

I've gone so far as to test how the surfaces mate with Prussian Blue. It was more for the principal and being able to tell the customers I did it to each one (of a couple dozen).... and a test to see how good or bad the carrier's surface was. The carrier key is easy, as you pointed out. In these recent "batches" where I had a bunch to do, I ran them (keys) over 150 grit wet/dry paper on my surface plate, a couple strokes tells you if it's flat and if it's not, a few more strokes will make it so. Not need to worry about dimensions, you'd really have to work at it to reduce that surface even a few thou. In the carrier's mating surface I will get on it with a stone sometimes if it looks particularly bad.

Everything has to be perfect, of course..... but to be honest, not "perfectly" perfect. I don't think a half-thou or even a thou of non-contact will shut a gun down.... long as it doesn't get worse via loose screws. Anyway, a little Permatex will probably take care of that. It's part of the spec and I'm not sure it's a huge help but for sure "it don't hurt nuthin' ".

The Machinery's Handbook tells us that lubed threads give more clamping force-- you mentioned this in your vid. You're right and it's up to 30%! Myself though I do use red LocTite on carrier key screws when I can. I would never bet everything on any wundersubstance but as added insurance it's pretty good. I have not observed a difference in failure rates between well-torqued and staked keys assuming good screws (not necessarily OCKS), between Loctited / not LocTited. The reason I have not observed a dif is because given the preceeding (tq, staking, proper screws), neither one fails, simple as that. So in my opinion thread locker is not the big determiner of success or failure but still, better with than without and that's because it will act as a lubricant during installation giving you that extra clamping force but without over straining the screws by over torquing.

[SOTAR]

Totally not gonna happen but with you there I think they can still be pulled from the fire and get the advice they need. In other words, glad to see you here.

I watched your carrier key swap / stake vid, good stuff and your modified staking screw profile has merit. We do things very similarly; when I'm doing a swap or restake it's usually one at time in more or less field conditions, but in the last year I've had occasion to do some small batches for people. That's where one starts trying to introduce more efficiency into everything which then makes for better processes back in the onsey-twosey scenario.

I've gone so far as to test how the surfaces mate with Prussian Blue. It was more for the principal and being able to tell the customers I did it to each one (of a couple dozen).... and a test to see how good or bad the carrier's surface was. The carrier key is easy, as you pointed out. In these recent "batches" where I had a bunch to do, I ran them (keys) over 150 grit wet/dry paper on my surface plate, a couple strokes tells you if it's flat and if it's not, a few more strokes will make it so. Not need to worry about dimensions, you'd really have to work at it to reduce that surface even a few thou. In the carrier's mating surface I will get on it with a stone sometimes if it looks particularly bad.

Everything has to be perfect, of course..... but to be honest, not "perfectly" perfect. I don't think a half-thou or even a thou of non-contact will shut a gun down.... long as it doesn't get worse via loose screws. Anyway, a little Permatex will probably take care of that. It's part of the spec and I'm not sure it's a huge help but for sure "it don't hurt nuthin' ".

The Machinery's Handbook tells us that lubed threads give more clamping force-- you mentioned this in your vid. You're right and it's up to 30%! Myself though I do use red LocTite on carrier key screws when I can. I would never bet everything on any wundersubstance but as added insurance it's pretty good. I have not observed a difference in failure rates between well-torqued and staked keys assuming good screws (not necessarily OCKS), between Loctited / not LocTited. The reason I have not observed a dif is because given the preceeding (tq, staking, proper screws), neither one fails, simple as that. So in my opinion thread locker is not the big determiner of success or failure but still, better with than without and that's because it will act as a lubricant during installation giving you that extra clamping force but without over straining the screws by over torquing.

Ned,

You made me blush. Thank you for the kind words.

The AR Community is truly blessed to have you and the tools and gauges you produce.

I hope that me modifying your MOACKS does not come across as a slight to your wonderful product. I'm a tinkering nerd and I'm always trying to improve my work and troubleshooting.

Thanks for all you do.

[BillB]

I am not an AR mechanic by any means. Before torquing this back together I would check for flatness on the carrier and the base of the key.

Understand this from my mechanical experience. A torch will not ignite the cheap blue Permatex Formagasket. The copper "high temp" certainly won't succumb to the heat. I don't know which gun cleaning chemicals would weaken the silicone.

I was just checking to see if either screw was loose. They appear not to be.

[Ned Christiansen]

No slight whatsoever! Keep up the good work.

[CESwartz07]

Ned,

You made me blush. Thank you for the kind words.

The AR Community is truly blessed to have you and the tools and gauges you produce.

I hope that me modifying your MOACKS does not come across as a slight to your wonderful product. I'm a tinkering nerd and I'm always trying to improve my work and troubleshooting.

Thanks for all you do.

First of all, I’m a big fan and I love your videos and other content, and hope to come to your 2-day class one day.

I’m curious if when you or Ned advocate for stoning the bottom of the carrier key, is there any concern about corrosion since it’s removing most of the phosphating?


Sent from my iPhone using Tapatalk Pro

[SOTAR]

First of all, I’m a big fan and I love your videos and other content, and hope to come to your 2-day class one day.

I’m curious if when you or Ned advocate for stoning the bottom of the carrier key, is there any concern about corrosion since it’s removing most of the phosphating?


Sent from my iPhone using Tapatalk Pro

Thank you for the kind words.

I do stone the bottom of the carrier key before I install them. You do run the risk of corrosion if you don't use a sealant. I use Loctite 620.

[CESwartz07]

Thank you for the kind words.

I do stone the bottom of the carrier key before I install them. You do run the risk of corrosion if you don't use a sealant. I use Loctite 620.

Thanks for the reply. I was considering redoing my sandcutter with the OKCS. Not that there is a problem, but I like to tinker on my own stuff to learn hands on. I saw in another thread that you don’t recommend chrome gas keys due to staking issues, but I was thinking that might be the solution. Not only that but the phosphate key on the chrome sandcutter just looks out of place anyway. I considered looking for an NP3 key.

One other question: how does one join your Facebook group? I keep hearing about it, but can’t find it. I figure it must be invite only?


Sent from my iPhone using Tapatalk Pro

[SOTAR]

Thanks for the reply. I was considering redoing my sandcutter with the OKCS. Not that there is a problem, but I like to tinker on my own stuff to learn hands on. I saw in another thread that you don’t recommend chrome gas keys due to staking issues, but I was thinking that might be the solution. Not only that but the phosphate key on the chrome sandcutter just looks out of place anyway. I considered looking for an NP3 key.

One other question: how does one join your Facebook group? I keep hearing about it, but can’t find it. I figure it must be invite only?


Sent from my iPhone using Tapatalk Pro

The NP3 will likely chip at the edges of the staking. It will stake cleanly but it the NP3 might not look great.

A chromed carrier key won't stake as cleanly as a phosphate one will.

You may have better success than I have with Chrome, so don't take my word as gospel.

The Facebook Group was hidden and capped at 5k members to try and maintain quality content. I just cleaned house and opened membership so you should be able to get in.