Hi All. I'm hoping you can educate me and also help others avoid a costly mistake down the line. A huge thank you in advance for any info you can offer.
I need to store guns/parts for ~10 years. I've been brushing on "RIG Universal Gun Grease" petrolatum/sulfonate grease. It comes in a big jar and cleans up easily. From what I read, it's an old school formulation and more storage/corrosion inhibiting grease (or at least the marketing dept says so) instead of anti-wear.
Parts then get wrapped in PE foam and finally into 5mil aluminized poly bags and sealed with O2 and desiccant. I'm right on the coast so I'm ocd about moisture & corrosion. I've had parts saturated in machining oil totally rusted within a year.
The more I learn about greases, and specifically this grease, the more I think I made a huge mistake.
SDS Composition: Birchwood Casey RIG Grease
1- PETROLATUM: CAS 8009-03-8 > 60-75%
2- SODIUM ALKYL ARYL SULFONATE: CAS 93820-59-8 > 10-20%
3- DISTILLATES, PETROLEUM, HYDROTREATED MIDDLE: CAS 64742-46-7 > 1-10%
4- DISTILLATES, HYDROTREATED LIGHT NAPHTHENIC: CAS 64742-53-6 > 1-10%
First issue was when I brushed this grease onto an anodized aluminum receiver by accident (while coating a steel barrel) and the scent immediately changed. It was a very distinct chemical smell, almost like a roll of freshly developed film. On steel, it smells the same as in the jar; totally different when on anodizing. I thought this can't be good so I started researching the reaction/cause/petroleum sulfonates and ended up here with further questions and concerns.
My concern is this grease may oxidize and harm / discolor / corrode anodized aluminum and now also any steel over long term storage. So a few questions for the experts smarter than I:
1 - Is this formulation unstable and will it oxidize / breakdown into acetic acid, other acids/salts etc? If breakdown is likely, is this a valid concern or it is on a small scale that it should not be a major issue?
2 - What exactly is Petroleum/Sodium Sulfonate? Do Sulfonates harm anodizing/aluminum over a long term?
3 - What about the PH of this grease? Is there an easy way to determine? and could that be responsible for the smell once it hits aluminum? Is PH even a concern on aluminum once anodized and sealed? (I read Aluminum oxide film is stable when pH is between about 4.0 and 8.5)
4 - Are any other listed ingredients incompatible with Anodized aluminum? (dimethyl sulfoxide less than 3%)? What about incompatibilities with steel?
5 - Is there a specific aluminum grease (ph compatible, anti-corrosion) that will also work on steel that you could recommend? Or are they like cutting fluids, separate formulas for ferrous and nonferrous?
The MSDS specifically names SODIUM ALKYL ARYL SULFONATE but the CAS# 93820-59-8 comes back as "BENZENESULFONIC ACID, DI-C10-18-ALKYL DERIVATIVES, SODIUM SALTS"
6 - Are these ingredients harmful to steel / aluminum? And why the discrepancy on the SDS?
All aluminum is 6000/7000 series \with a black hardcoat Type III anodize + sealed finish. I'd like to avoid discoloration and damage during storage.
Also, these assemblies can't be separated, otherwise that would have solved the issue altogether.
I started several test pieces in the atmosphere as an experiment. After a week, I see a slight change in the anodizing to a more grey tint (from black. The chem smell does go away. However, that doesn't indicate too much for long term and the aluminum underneath the anodize.
Thank you in advance for any advice you have.
I need to store guns/parts for ~10 years. I've been brushing on "RIG Universal Gun Grease" petrolatum/sulfonate grease. It comes in a big jar and cleans up easily. From what I read, it's an old school formulation and more storage/corrosion inhibiting grease (or at least the marketing dept says so) instead of anti-wear.
Parts then get wrapped in PE foam and finally into 5mil aluminized poly bags and sealed with O2 and desiccant. I'm right on the coast so I'm ocd about moisture & corrosion. I've had parts saturated in machining oil totally rusted within a year.
The more I learn about greases, and specifically this grease, the more I think I made a huge mistake.
SDS Composition: Birchwood Casey RIG Grease
1- PETROLATUM: CAS 8009-03-8 > 60-75%
2- SODIUM ALKYL ARYL SULFONATE: CAS 93820-59-8 > 10-20%
3- DISTILLATES, PETROLEUM, HYDROTREATED MIDDLE: CAS 64742-46-7 > 1-10%
4- DISTILLATES, HYDROTREATED LIGHT NAPHTHENIC: CAS 64742-53-6 > 1-10%
First issue was when I brushed this grease onto an anodized aluminum receiver by accident (while coating a steel barrel) and the scent immediately changed. It was a very distinct chemical smell, almost like a roll of freshly developed film. On steel, it smells the same as in the jar; totally different when on anodizing. I thought this can't be good so I started researching the reaction/cause/petroleum sulfonates and ended up here with further questions and concerns.
My concern is this grease may oxidize and harm / discolor / corrode anodized aluminum and now also any steel over long term storage. So a few questions for the experts smarter than I:
1 - Is this formulation unstable and will it oxidize / breakdown into acetic acid, other acids/salts etc? If breakdown is likely, is this a valid concern or it is on a small scale that it should not be a major issue?
2 - What exactly is Petroleum/Sodium Sulfonate? Do Sulfonates harm anodizing/aluminum over a long term?
3 - What about the PH of this grease? Is there an easy way to determine? and could that be responsible for the smell once it hits aluminum? Is PH even a concern on aluminum once anodized and sealed? (I read Aluminum oxide film is stable when pH is between about 4.0 and 8.5)
4 - Are any other listed ingredients incompatible with Anodized aluminum? (dimethyl sulfoxide less than 3%)? What about incompatibilities with steel?
5 - Is there a specific aluminum grease (ph compatible, anti-corrosion) that will also work on steel that you could recommend? Or are they like cutting fluids, separate formulas for ferrous and nonferrous?
The MSDS specifically names SODIUM ALKYL ARYL SULFONATE but the CAS# 93820-59-8 comes back as "BENZENESULFONIC ACID, DI-C10-18-ALKYL DERIVATIVES, SODIUM SALTS"
6 - Are these ingredients harmful to steel / aluminum? And why the discrepancy on the SDS?
All aluminum is 6000/7000 series \with a black hardcoat Type III anodize + sealed finish. I'd like to avoid discoloration and damage during storage.
Also, these assemblies can't be separated, otherwise that would have solved the issue altogether.
I started several test pieces in the atmosphere as an experiment. After a week, I see a slight change in the anodizing to a more grey tint (from black. The chem smell does go away. However, that doesn't indicate too much for long term and the aluminum underneath the anodize.
Thank you in advance for any advice you have.
