I’m going to install a Sully Stock on my AR this week and have been reading that I should grease up the threads with an anti-seize compound, with the caveat being that it should be a molybedium diesulfide based grease and that it should not contain graphite. So far, everything I’ve found contains graphite and brake caliper greases, even those with the word “Moly” in the name contain graphite. WHere can I find the right stuff?
odd… i haven’t had any trouble. walmart has tubes of their brand grease- that’s currently what i’m using for all my anti-seize needs. it’s called molylithium or lithiumoly or some shit like that… blue tube.
ETA
'ere it is…
picture credit - Nick_Escalante
Napa auto parts
yea… if your local napa isn’t full of assholes, just ask them.
looking through my stack… i actually have about 5 different types of grease that i’ve used at different times. bearing grease, general high-temp grease, molybdenum grease, some shit in a big flex tube that i cant read anymore (but remember using)… and whatever is inside of this grease gun… plus the supertech moly-lithium.
i really dont think it matters too much… just make sure it’s something that can take high temp. like high-temp grease.
So just go into Wally World and ask for “the shit in the blue tube”…:sarcastic:
I use Loc-tite C5A and have yet to experience any issues. I used it on barrel nuts and receiver extensions. Probably have done somewhere in the area of hundred(s) using it.
Anti-seize isn’t a necessity on the receiver extension installation, but can be useful for some. It certainly does no harm. I use it on my builds. No preferences, whatever is handy. Usually mil moly-b.
What’s the problem with using anything on hand? This is a receiver extension, not a barrel nut. This area isn’t subjected to high heat.
Also, this is a Sully stock, not an adjustable stock. If anything required grease to assist future disassembly, I would think the nut that holds the stock onto the extension would be torqued the heaviest. I’m not a builder though, these are my uneducated thoughts.
Any molybdenum-based grease will be fine. By seizing, they mean either oxidation (rust) or galling such as occurs with dissimilar metals. Since it’s aluminum-on-aluminum, galling won’t happen.
Castle nuts are not aluminum. I have seen castle nuts that had no anti-seize or anything else applied to them become extremely difficult to remove.
Heh! Only steel and iron rust. Aluminum corrodes
The moly-Lithium grease is great on that, and other stuff (snare drum heads, etc.), if you’re going to use anything that would be it.
“Corrosion” of aluminum is the same process as “rust” on steel - oxidation.
Wound up picking up some break caliper and bearing grease by Valvoline - lithium based with molybdenum disulfide added. operating temp up to 375 deg.F. Sounds like it’ll work. Thanks for the help.
Perhaps to a layman. But if I ever wrote “Rust found on cargo floor support at Sta. 727 + 4, Stringer 25” on the discrepancy form I’d be laughed out of the hangar because the support is made from aluminum
According to the the FAA approved data I must use and which is based on established scientific and metallurgical standards, rust is defined as iron oxide.
(There is another form of rust involving iron and I believe chlorine, but I don’t recall the details)
oxidized aluminum is anodize- aluminum oxide. it doesn’t eat through the aluminum, damaging the part. rust on steel might be iron oxide, like aluminum oxide, but it quickly ruins the part.
might be similar on the surface, but thats where the similarity stops.
Now - how crucial is it to tighten an entry length tube to a specific torque? This is a little pre-mature since I don’t have the parts or instructions in-hand yet, but I assume the entry length tube will have to be tightened using a similar torque to a rifle length tube (35 ft-lbs). My wrench cannot be fitted to a torque wrench, so instead, I was planning to figure out how much force I have to apply based on the moment arm of my wrench, and practice pushing on my bathroom scale, and then going on muscle memory. Stupid or reasonable?
The receiver extension tube on a Rifle is set at 35-39 ft lbs. The castle nut on a carbine is set at 38-42 ft lbs. Some of the old military rifle maintenance manuals have a typo on the carbine listing it at 40 +/- 2 in lbs, when it should be ft lbs.
I use a moly grease and I like to work all of my threads by tightening and loosening 3 times before setting final torque. Some don’t use grease when working threads, I do. Quite honestly I do not even use a torque wrench when doing this, or when setting final torque. I have very closely calibrated hands but I do this type of work a lot. 
INCH pounds for receiver extensions- not foot pounds.
Have you ever applied 40 inch pounds to a castle nut? I mean on an actual torque wrench? This equates to 3.3 ft lbs. I can nearly hand tighten to this spec. I use a 45 inch pound t-handle torque wrench on small scope rings. Even with a slight turn using a standard castle nut wrench I am already at around 10 ft lbs.
In any event, the Colt manual calls for foot pounds. I have also talked to Ken Elmore about this and he also says ft lbs. Even since he has left Colt, Colt still gives and teaches this torque spec. I know for sure that I am nowhere near as low as 3.3 ft lbs or 40 in lbs.
I had to search for it, but I have discussed it here before. Here is the thread. My discussion starts on page 2.
https://www.m4carbine.net/showthread.php?t=38672&page=2
So, either the mil maintenance manuals are wrong, or Colt and Ken Elmore is wrong. Either way, I do not use a torque wrench when doing this and I know I am a good deal higher than 40 in lbs, plus or minus 2 inch pounds. Or maybe I like to go tight on things. I know that with a barrel nut, I like to be in or near the 65-70 ftlb range as opposed to the low end of the torque setting. 