Unusual anti-seize compound

[FowVay]

I experienced a rather unusual situation today. I was doing a inspection on a air seal inside of a GE CF6-80A2 jet engine. While reading through the inspection criteria I noticed that the reassembly procedure included using a anti-seize compound on the attach fasteners. I chuckled when I saw that the compound recommended was Milk of Magnesia-unflavored.

So maybe I'm going to get a bottle of this stuff and start using it around the garage and see how well it performs.

 

[Jackpot01]

There was a garage I went to a few years ago and I noticed a bottle of MOM there. I thought the mechanic just had some heartburn

Eric

 

[tom slick]

i'll venture to guess that you were putting it on spark ignitors or turbine/combustor area? the GE F110 and F101 series engines i worked on use the same thing. it works quite well in extreme heat situations.

 

[427Z06]

Yep, MoM as a high-temp anti-seize compound. I remember that from my USAF glory days.

 

[HunterG69]

What seal was that? Every now and then I get my hands on the LM6000, very similar to the 80C2. Don't doubt it at all. I've never seen that anywhere. Was it in the standard practices?

I'll tell you a story about the explosive rivet and my knuckle......never mind.

 

[FowVay]

The actual manual that this was printed in was the ESM chapter 72-55-05 if you have access. The topic is Weld repair to the low pressure turbine 1st stage nozzle inner liner. If you scroll the manual to paragraph 2B it lists the consumable materials for the repair. This is where it specifically calls for Milk of Magnesia. I took the material item number to the SPM, chapter 70-80-02-800-013-0 and followed this chapter to the specific Milk of Magnesia item which is C02-061. This is listed as magnesium hydroxide + water.. commercially available. It does list a substitute for the milk of magnesia which is Never-Seez something or other that is made from Nickle.

So yes, the item is listed in both the Engine Shop Manual and the Standard Practice Manual and this is a approved high temperature anti-seize compound. I learn something neat every day

 

[HunterG69]

We are actually moving away from Nickel based anti-seize compounds and adopting collodial graphite ones. The trend is driven by HS&E considerations where the Nickel is a hazardous material. We use one made by ROCOL and approved for use in assembling the Industrial RB211. the LM approved item is a CO2 - something or other.

 

[labman]

What effect would MOM have on bolt torque? There have been a couple of threads here on anti seize or not for wheel studs. The manufacturers give dry thread torque. Myself and others are too concerned with breaking a stud to do that. The consensus was somewhere near use anti seize, but reduce the torque to 80%. With what little dissolves in water being ionic, would it be corrosive in wet environments?

 

[FowVay]

I don't know what effect the MoM would have but while passing some time at Barnes and Nobles bookstore I was thumbing through a little reference book that listed everything in the world in it. It had a 2 page chart that referenced torque values and how they're affected by the application of lubricants on the threads.

If I buy the little book I'll see if there's anything worth posting on here that would benefit the group.

 

[427Z06]

I read on a spark manufacturer web site that the torque values should be reduced by 1/3 for lubricated threads. However, I also noticed their torque values for various size spark plugs/gaskets were on the high side compared to manufacturer recommedations.

ARP bolts/studs give a more detailed recommendation:

ARP recommendations

 

[jamesn]

i had hear of the MOM and thought it was an old wives tale. i guess they really use that stuff. finely powdered mag hydroxide does sound handy for it though.