I have been hearing lately that some believe using Moly based grease on builds is actually not good so I wanted to get feedback on what you all think. Some are saying that when used between steel and aluminum it actually can cause corrosion. I know that the TM9-1005-319-23 calls for it on upper assembly builds. I have always been under the impression that it should be used when assembling dissimilar metals..i.e. Alum. upper and Steel barrel. But I recently noticed in the TM9 that they say to use it when assembling CAR buffer tubes into lowers...which...obviously are both aluminum.  But better yet...Moly grease necessary on a buffer tube??? Considering everything else is fine with CLP,,,what gives?

I recently spoke with an Armorer at LMT and during the conversation, for kicks, asked what the assembly grease is that they use and prefer on their upper builds since this stuff is a real pain to get off! They said they use a product called Chuck-Ezzz which has a low amount of Moly (25%) in some super duper grease. It's used quite a bit in the machining industry.

www.chuckeez.com/

So...does using Moly based grease actually increase corrosion or no?

The listed torque values apply when using a lubricant, They would be differnet if none were used. If you put aluminum together with out a lube it is almost impossible to get apart sometimes.

Nope. graphite will screw things up
I believe the only place you use moly-grease is on the trigger sear. Everything else is CLP

Quoted: Nope. graphite will screw things up I believe the only place you use moly-grease is on the trigger sear. Everything else is CLP

+1

Neco Moly-Slide on the sear and CLP where applicable.

So I guess the TM9 is wrong...

People keep posting this stupid idea that alum and grahpite is a no no.  Please cite one reputable source for this statement.  And why mix discussion of molybelium disulfide and graphite?  MoS2 has no carbon in it at all.  Graphite is carbon, and nothing else.  

I have used graphite based anti seize on auto and marine applications for years just to prevent the problem of galvanic bonding and corosion and it works without fail.  It is however, messy to work with.

Why people believe the advice they see on these boards without confirming what they read is beyound me.  

The TM is correct.  

Armalite manual says 'no graphite'. I was thinking moly-base was different and OK.

Galvanic corrosion is a well established fact.  Aluminum is on the anodic end of the scale, and graphite is on the cathodic, or opposite end of the scale.  When these two conductors are brought together (generally speaking,  with the presence of water or some other electrolyte), the aluminum will corrode faster than normal, and the graphite will corrode slower than normal.  However, that rate of corrosion is not totally predictable.  Still, graphite and aluminum should not be used together.  Here you can see how different metals compare.  There is a lot of information about galvanic corrosion on the web.

A little moly grease on the buffer tube threads won't hurt a thing, and will make it earier to disassemble should you ever want to do so in the future.  Oils will eventually dry up over a period of time.

Quoted: Armalite manual says 'no graphite'. I was thinking moly-base was different and OK.

Moly Grease is fine.

The TM is correct, and Moly grease is pretty easy to find.  It should be used on the barrel nut in all cases - steel on aluminum or aluminum to aluminum.

tag

The link you posted spells out one reason why they want Moly. It takes more clamping pressure to displace it than a graphite lube does. Also the torque values in the manual are for use with a lubricant not without one.

The galvanic worry from graphite has never worried me. It take a third thing such as salt water for it to be a problem. I seldom swim in the ocean for extended periods with my gun. I have taken uppers apart I put together over 10 years ago with anti seize and they were fine. I have never had a barrel nut loosen up because of the lube I used either but I have always used very little and did the muti tighten thing.

Even with the application of water and electricity, no corrosion has ever bee seen on my alum marine engine.  Spark plugs in my autos  (also all alum engines) also have not suffered any corrosion.  I suspect this whole graphite question is without grounds and based on my experience, and that of any one who works on alum engines, it should be dismissed as another urban myth.

However, I am willling to make an exception for those of you who use your ARs as extension cords while holding them in salt water.  I caution you to be careful not to let the rifle corrode.  Any other ill effects you might feel while doing this are your own damn fault.