Fatty Acid Corrosion of Copper from Wax Lube

[Ricochet]

These are #429244HP bullets that I cast in 2007, with normal copper Gator checks on them. I dipped them in my homemade lube (which shoots well) that started off as a can of Johnson's Paste Wax and as I used it down I topped it back up with yellow beeswax, yellow raw anhydrous lanolin, most of a slack wax toilet bowl ring, scraps of random paraffin waxes and a bit of Alox 606-55. I have quite a few bullets that have been stored for years in this basement which has flooded on several occasions and accordingly has had high humidity. The bullets were in a bag open to air, not in sealed plastic containers as many of them are. All of my gas checked bullets stored after dipping them in the molten lube show this heavy green verdigris on the copper checks. Unused checks and other copper and brass items have not done this, only where they were coated with lube. I think this is fatty acid corrosion on the copper. The ingredients containing fatty acids are beeswax and lanolin. I've never heard of beeswax doing this, but I seem to recall reading that unrefined wool fat may contain a good bit of free fatty acids. Come to think of it, I saved and put in a good bit of that soft red wax that some cheeses come coated with. I suppose that could have something to do with it. It won't hurt a thing to shoot these this way, but I need to be sure I don't leave any of this loaded in cartridges long lest they corrode the brass case necks. Has anyone else run across this?

 

[Ian]

I've never heard of beeswax doing this, but I seem to recall reading that unrefined wool fat may contain a good bit of free fatty acids.

Actually, Eutectic and Bruce381 both from the CB forum enlightened me on the fact that beeswax alone will cause verdigris and also lead oxidation. The subject came up about five years ago when I noticed similar corrosion of some rifle bullets lubed (but not loaded) with Felix lube and stored under ideal conditions in a plain cardboard box (NOT a cigar box per my normal routine). I thought it was the soap, but more likely it was the lanolin and beeswax doing the mischief as I was informed.

For going on three years now I've used a lube with very, very high sodium soap content and have found really minimal corrosion on anything, but it contains no "natural" ingredients save for a very small amount of castor bean oil, which is polymerized to the point that it likely has no free fatty acids remaining. Since switching away from FWFL, the insides of my antique iron Lyman 45 sizers have stopped leaching brown residue into the lube, and the only signs of corrosion I see at all are dark fingerprints on bullet noses if I don't keep the lube wiped off my fingers when sizing the batch for storage.

I never noticed corrosion issues using any sort of lube that contained a significant portion of chassis grease as a component. This is probably due to the anti-oxidants and corrosion prevention additives in the grease that protect the oils themselves from reaction with oxygen as well as metal surfaces to which the grease is applied.

 

[fiver]

I have seen cartridge cases get that same green on them too when stored in a higher humidity area.
it's just a form of oxidization.
the white on the lead is from humidity too. [and is oxidization also]
I have seen it form on ingots stored outside, the odd thing was stick on ww's got it much more severely than the clip on ingots and sooner too.

I think the bees wax as inert as it is on it's own gasses off a little bit of the ester alcohols over time and that reacts with the copper to oxidize it faster.

I also recall that the stearate used in the faux felix lube many were making some time back with the stearic acid instead of ivory had this same thing crop up as a concern.
I don't think I have ever seen a micro-wax lube do this.

 

[Glen]

I suspect that the water (flooding) and humidity are major players in this corrosion, as the lead is just as corroded as the copper.

 

[Ricochet]

Yeah. But the funny thing is, I have lots of other lead bullets from that era that are shiny, none of my unused checks or brass cases are tarnished, let alone green, steel tools aren't rusted, but all of my checked bullets that I dipped before storage look like this.

 

[quicksylver]

HUUUUM All I can add is that I have MI carbine bullets that have been stored in various places since 1977, they were gas checked and lubed with 50/50 and look about a year old.

 

[.22-5-40]

I have noticed this on gas-checked .30 lead bullets using my home-made beeswax based lube containing anhydrous lanolin, synthetic spermaceti wax ( from the late Charlie Dell) and castor oil. Noticed it on the brass pressure ring on a Lyman 45 lubesizer also. Items stored in dry basement. At first I thought it was the synthetic spermaceti..but have since noticed it from beeswax/ anhydrous lanolin mixes. I think it might be the anhydrous lanolin re-hydrating from atmosphereic moisture?

 

[fiver]

anhydrous lanolin contains water,, about 3%

 

[Ricochet]

Yes, and I don't have time to search now but I'm pretty sure I've read that it contains a good bit of free fatty acids and unesterified lanolin alcohols. (Lanosterol and cholesterol.) That's supposed to be what causes a good many people to break out with rashes from lanolin. And I do have checked bullets that have been sealed in airtight plastic containers that look just like these. I just loaded 20 of these in .44 Magnum with full loads of WC820, BTW. They're almost too long to slide back into the original Winchester-Western cartridge box that the cases came in, they're a tight fit, but have a little room to spare in the cylinder of the "new" Taurus Model 44 I just picked up. It's not as big as a Raging Bull or an X-frame, but it's a real hogleg with its 8 3/8" barrel.

 

[Ian]

Lanolin also causes first shot issues in several lube formulas with rifle barrels normalized below around 40°F, so for that reason alone I don't use Lanolin anymore in my lubes. Lithium soap makes an excellent substitute for the properties of Lanolin without the drawbacks....until you get to the upper end of the ambient and barrel temperature spectrum.

When the Felix/Wiljen lube issues surfaced I attributed it to the un-saponofied stearic acid that was substituted for the sodium salt in Ivory soap. What really should have been added instead of stearic acid was a small amount of sodium hydroxide, just enough to saponify the FFAs in the beeswax, lanolin, and carnauba wax. I tried to figure the saponification values of those three once and gave up for fear of over or undershooting the mark with Lye percentage.

 

[Ricochet]

I'm a soapmaker myself. My specialty is heavily overfatted stuff that the ladies love as face soap. I've thought about trying it as lube, but now I think that's not such a great idea with all of the partially saponified or unsaponified fat in it.

 

[Ricochet]

Here is one of these from the same batch, when they were new.

 

[Ricochet]

Here are some just loaded in Winchester -Western cases I've had since the early '70s, over a full load of WC820. I'll want to use them soon so the lube doesn't corrode the brass too much.

 

[fiver]

those look like they followed the same path of life as I did.
I remember being pretty, shiny, and fairly new. [I might have even been copper bottomed at one point]
and now I am all oxidized and vertigrised up too.

 

[Ricochet]

Same here!

 

[Pistolero]

Dissimilar metals corrosion would be my diagnosis. I had a full course in corrosion in
grad school and this is a fairly classic case, although much less active than say, aluminum
and steel.

Lead in contact with copper, with an electrolyte (humid air will do quite nicely) is a battery,
and the difference in galvanic voltage, while only about 0.2 volts, is enough to drive the corrosion at
a accelerated rate.

I suspect that any acids which are soluable will improve the effectiveness of the electrolyte,
so no doubt that the lube plays a role, the lead and copper by themselves in a liquid with
any ions will corrode quite nicely with no other assistance.

If they are kept dry, the corrosion becomes highly localized - like only where they are in
direct contact, and even then, fairly slowly. Expect aluminum checks, with 4 times the
voltage difference, to corrode much more readily and produce more damage.

Bill

 

[.22-5-40]

I just pulled some black powder .40-70 21/2" loads that were made up about 1 year ago. Cases were water cleaned & tumbled before loading. Lube was SPG. Every pulled bullet had greenish tint to only middle band of lube (350gr. Brooks Creedmoor)..up to this time, I had thought only my home-brewed lube gave this staining.

 

[Pistolero]

Clearly the brass case and the lead bullet form a primary battery and if the lube can act as an ion carrier, there will be
corrosion by electron exchange.
Another thing to consider when developing bullet lubes.

Bill

 

[Lost Dog]

Fascinating information on electricity produced by assembled ammunition. Correct me if I miss something here, when the electrons begin to flow creating current, cannot the lube form a source of insulation? I can readily see where it would be a good conductor if water based or similar. But if indeed a lube possesses electronic insulation quality would it not lend to the reduction, or even halting the current flow from the two components?

I have not encountered this phenomenon of a loaded cartridge becoming a dry cell battery followed by outward corrosion. Only rapid forming corrosion due to catastrophic absorption of atmospheric moisture within a barrel of a weapon from powder fouling. But I am well enough educated in electronics to understand the principles involved here. Again, fascinating information on an obviously little known subject.

 

[Pistolero]

If electrons can flow, which usually requires ions which are mobile, then the lube can
act as an electrolyte. Certainly some lubes have little conductivity, and would be helpful
in preventing this. But some natural materials have water in them and salts dissolved so
they would function as an electrolyte, although a relatively poor one, it would seem compared
to a normal battery electrolyte like sulphuric acid for lead based cells and potassium hydroxide
for nickel cadmium cells - both of which are secondary cells. A primary battery is one where
the electrodes are consumed in making electricity, like the copper penny and a iron nail punched
into a lemon, a common demonstration of primary battery. Secondary batteries are rechargable.

Bill