New FSB installed with screws - use loctite or not?

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[ARCHIVED THREAD] - New FSB installed with screws - use loctite or not?

Posted: 2/17/2006 9:09:02 AM EDT

I installed a YHM flip-up front-sight base/gas block on one of my rifles, and am wondering if it would be a good idea to put some blue loctite on it, just to be sure.

One the one hand, I wonder if the screws might loosen over time - but since the gas block area probably gets really HOT, I also wonder if blue loctite would do any good, as I believe it loosens when heated anyway.

What have you guys done in the past - or is the YHM type of "clamp-on" front sight base just a bad idea from the get go?

ETA: The installation instructions from YHM do not mention loctite, just say to tighten the screws.

Posted: 2/17/2006 9:16:48 AM EDT

[#1]

Those things have been popping up all over. I'm going to put one on a rifle because it looks cooler than the one I have and we all know that looking cool is the main thing.

I'm gonna use red loctite.

Posted: 2/17/2006 9:19:26 AM EDT

[#2]

Quoted:
Those things have been popping up all over. I'm going to put one on a rifle because it looks cooler than the one I have and we all know that looking cool is the main thing.

I actually don't particularly like things like that (just seem more flimsy and prone to breakage that a regular FSB), but I really wanted to get it out of the way for my EOThingy - for all my other rifles, I'm perfectly happy with the standard (and solid) base.

I'm gonna use red loctite.

Because the blue one will loosen because of heat? Or jsut because red is stronger in general?

Sorry, I'm a complete loctite newbie

Posted: 2/17/2006 9:29:23 AM EDT

[#3]

Red is stronger. I dunno about the heat. I think there is some purple stuff that is even stronger. I wish they'd just make one we could have pinned.

I want to mount my 3.5X10X40mm scope as low as possible. I'm going to use flip sights front and rear. I want to mount my scope forward of the rear flip site, which has nothing to do with the conversation, actually.

Posted: 2/17/2006 10:09:01 AM EDT

[#4]

Thanks!

Posted: 2/17/2006 10:24:15 AM EDT

[#5]

I haven't found blue loctite useful on gas block/FSB screws. I am assuming because of the heat. I do use it everywhere else though.

Posted: 2/17/2006 10:27:09 AM EDT

[#6]

Loctite that puppy!

Posted: 2/17/2006 10:40:52 AM EDT

[#7]

Quoted:
Loctite that puppy!

Red or blue?

Posted: 2/17/2006 10:47:16 AM EDT

[#8]

Red

Posted: 2/17/2006 10:49:23 AM EDT

[#9]

23,531 posts on ARFCOM and you do not know if locktite is a good idea or not?

Personally, I think low profile gas blocks should be pinned. Red should be considered the bare minimum.

Posted: 2/17/2006 10:54:40 AM EDT

[#10]

Also, replace the supplied screws with torx head cap screws for much greater clamping force. If you can search the archives, I started a thread discussing that topic several months ago. I made the swap and the amount of torque you can apply is significantly greater than when using the standard hex heads.

Posted: 2/17/2006 11:19:07 AM EDT

[#11]

Quoted:
23,531 posts on ARFCOM and you do not know if locktite is a good idea or not?

I was just surprised that YHM didn't recommend it on their own webpage, in their installation instructions. (Perhaps to protect themselves against complaints from idiots who install it upside down or something, and then cant get it off because of the loctite

)

Personally, I think low profile gas blocks should be pinned. Red should be considered the bare minimum.

Thanks!!

Posted: 2/17/2006 11:46:31 AM EDT

[#12]

Quoted:
Quoted:
23,531 posts on ARFCOM and you do not know if locktite is a good idea or not?

I was just surprised that YHM didn't recommend it on their own webpage, in their installation instructions. (Perhaps to protect themselves against complaints from idiots who install it upside down or something, and then cant get it off because of the loctite )

Personally, I think low profile gas blocks should be pinned. Red should be considered the bare minimum.

Thanks!!

YHM doesn't tell you to use loc-tite because its operational teperature range is too low for the application. Unless you go with green loc-tite you will melt the strongest red at 400 degrees. That seams like a lot but that is not, 3 semi-auto mag dumps with get you to 400 degrees.

Posted: 2/17/2006 11:52:24 AM EDT

[#13]

Quoted:
Quoted:
Quoted:
23,531 posts on ARFCOM and you do not know if locktite is a good idea or not?

I was just surprised that YHM didn't recommend it on their own webpage, in their installation instructions. (Perhaps to protect themselves against complaints from idiots who install it upside down or something, and then cant get it off because of the loctite )

Personally, I think low profile gas blocks should be pinned. Red should be considered the bare minimum.

Thanks!!

YHM doesn't tell you to use loc-tite because its operational teperature range is too low for the application. Unless you go with green loc-tite you will melt the strongest red at 400 degrees. That seams like a lot but that is not, 3 semi-auto mag dumps with get you to 400 degrees.

Ah ha - so I'm definitely going to go to Home Depot and look for those torx screws that LarryLover was talking about above.

Maybe I'll throw on some red loctite anyway, just for giggles - can't hurt. Although this is on my 10.5" SBR, and I like the rapid-fire, so it defnitely gets hot fast.

Posted: 2/17/2006 11:59:24 AM EDT

[#14]

You have 2 choices due to the heat issue.

Blue #246 High temperature will hold up to 170 in lbs of torque and is rated up to 450deg

Red # 272 High temperature will hold up to 200 in lbs of torque and is rated up to 450deg

I would go with the blue, as the only difference between any of the blue and reds is the removal method. In theory all the blues will take the same amount of torque applied when fastening it to remove it.

With reds, it will take a heat in excess of 450deg to soften the product to allow the threads to slide and loosen up.

Hope this helps!

Posted: 2/17/2006 12:08:36 PM EDT

[#15]

in one of my ar-15 books it talks about locktighting the FSP on for DCM shooting. once it was adjusted for zero windage on the rear sight they put in green 190. which is a wicking compound applied to parts already put together.

just looked on loctites site and its 290 not 190.

heres the link to it.

tds.loctite.com/tds5/docs/290-EN.pdf

Posted: 2/17/2006 12:57:23 PM EDT

[#16]

tagged

Posted: 2/17/2006 1:03:15 PM EDT

[#17]

Quoted:
in one of my ar-15 books it talks about locktighting the FSP on for DCM shooting. once it was adjusted for zero windage on the rear sight they put in green 190. which is a wicking compound applied to parts already put together.

DING! We have a winner.
The penetrating green Loctite will do the trick. It will get down in the space between barrel and FSB.

Posted: 2/17/2006 1:17:02 PM EDT

[#18]

Quoted:
Quoted:
in one of my ar-15 books it talks about locktighting the FSP on for DCM shooting. once it was adjusted for zero windage on the rear sight they put in green 190. which is a wicking compound applied to parts already put together.

DING! We have a winner.
The penetrating green Loctite will do the trick. It will get down in the space between barrel and FSB.

You are exactly right, but keep in mind it will only hold up untill 300deg, then will get soft and lose it's holding capacity.

Posted: 2/17/2006 1:57:36 PM EDT

[#19]

Just remember green is more or less permanent. We use it on some assemblies at work that we do not ever want to come apart. I have heard 600 degrees or so to break it down.

[ARCHIVED THREAD] - New FSB installed with screws - use loctite or not?

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