AR15.Com Archives
 Red or blue loctite for gas blocks?
FALbert  [Team Member]
9/15/2006 3:05:26 AM EST
I recently completed two free float midlength builds. In both cases I used blue loctite for the allen screws to secure the low profile gas blocks figuring if I want to swap the barrel down the road, I can remove them without that much hassle.

In anticipation of a third build, I picked up a Larue LT 202-1 and it came with red loctite. Is red required for gas blocks where blue should be used for optics and BUIS? I can easily take the FF rails off and use red loctite. Anyone ever have a gas block where the set screws backed out while using the blue loctite? My question also applies to the PRI cross bolt block, as I have one that may be reused. Also, what is required to remove anything secured with red loctite? I have read the parts must be heated.

TIA
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bigbore  [Industry Partner]
9/15/2006 4:09:42 AM EST
red #266
ORinTX  [Team Member]
9/15/2006 4:11:44 AM EST
Heating helps enormously with red loctite, but it's not required if you can get enough torque and not strip or destroy the fasteners.

I have a little story I'm not proud of involving red loctite, the pistol grip screw, and a registered SBR lower.
ronemus  [Member]
9/15/2006 5:08:50 AM EST
I use green LocTite and flow it between the gas block and the barrel after everything is in final position. This has two advantages: the gas block won't move, and there are no gas leaks. Small leaks (and there are always some if you don't use LocTite) can fill the gap between the block and barrel with carbon that is very difficult to remove, cementing the gas block in place. When I need to remove the block, I just heat gently with a torch to break down the LocTite and it comes off easily (this doesn't work for carbon deposits).
dennysguns  [Industry Partner]
9/15/2006 5:52:31 AM EST
red
1_AR_NEWBIE  [Team Member]
9/15/2006 12:19:52 PM EST

Originally Posted By ronemus:
I use green LocTite and flow it between the gas block and the barrel after everything is in final position. This has two advantages: the gas block won't move, and there are no gas leaks. Small leaks (and there are always some if you don't use LocTite) can fill the gap between the block and barrel with carbon that is very difficult to remove, cementing the gas block in place. When I need to remove the block, I just heat gently with a torch to break down the LocTite and it comes off easily (this doesn't work for carbon deposits).


Green... Really? um...

Have you ever had to remove one you did this to?

Thinking,
Mike
mongo001  [Team Member]
9/15/2006 1:18:19 PM EST
Ya, green. Try it. It works.






























PS: Don't try to remove it.........................EVER!!!!
ronemus  [Member]
9/18/2006 5:38:37 AM EST
I've used green LocTite for 6 rebarrelings os the same upper with no problems. You just have to take it easy with the torch - just enough heat to burn out the LocTite, no more. The big advantage is that you can get everything set up true, the allow the LocTite to wick in without disturbing anything. It won't come apart until you release it with heat.
hellbound  [Member]
9/18/2006 5:50:15 AM EST

Originally Posted By bigbore:
red #266


whats the difference between 266 and 271 (red)?
556Cliff  [Member]
9/18/2006 7:22:43 AM EST

Originally Posted By hellbound:

Originally Posted By bigbore:
red #266


whats the difference between 266 and 271 (red)?


266=High Strength, High Temp. 271=High Strength.

266 is for up to 3/4" diameter threads. 271 is for up to 1" diameter threads.
hellbound  [Member]
9/18/2006 9:07:32 AM EST
so the 271 they sell at hardware stores is not high temp? i didn't see the 266 listed on the loctite site. i used the 271 to hold a KC Daylighter on a pushbar thats threads were somewhat stripped and it's held up so far for a few thousand miles of not so nice driving...

would normal barrel heat cause the set screw to loosen up if i use the 271?
1_AR_NEWBIE  [Team Member]
9/18/2006 2:06:06 PM EST

Originally Posted By ronemus:
I've used green LocTite for 6 rebarrelings os the same upper with no problems. You just have to take it easy with the torch - just enough heat to burn out the LocTite, no more. The big advantage is that you can get everything set up true, the allow the LocTite to wick in without disturbing anything. It won't come apart until you release it with heat.


What do you mean "wick in"?

Mike
defenderhome  [Team Member]
9/18/2006 4:38:11 PM EST
I would guess that he means capillary action.
556Cliff  [Member]
9/18/2006 5:23:32 PM EST

Originally Posted By hellbound:
so the 271 they sell at hardware stores is not high temp?


Correct


i didn't see the 266 listed on the loctite site.


It's there. For some reason it's in the medium strength category.


i used the 271 to hold a KC Daylighter on a pushbar thats threads were somewhat stripped and it's held up so far for a few thousand miles of not so nice driving...

would normal barrel heat cause the set screw to loosen up if i use the 271?


You can try it, if it doesn't work you can always buy some 266.
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