About six months ago, we had a thread in which some concern was stated with using Stearic Acid in making Felix Lube instead of Irory soap.
http://castboolits.gunloads.com/show...Version/page18
Some members had experienced corrosion of lubrisizers and cartridge cases and it was attributed to the Stearic acid.
Since I had just made a large batch of Felix using Stearic Acid this caught my attention. Up until that time I had not seen any corrosion on my brass or equipment. I decided to conduct a test to see if i could duplicate the corrosion.
I used three different metals in the test.
1. A polished 223 case. I coated the bottom half of the case with my Stearic Acid Felix lube.
2. Three Hornady copper gaschecks. One covered with Stearic Acid Felix lube, one filled with pure stearic acid and another untreated check as a control sample.
3. A piece of steel bar stock, the surface of which I sanded to get a clean surface. I treated one area of the bar with Stearic Acid Felix lube, another area was covered with pure Stearic Acid, and the remaining surface of the bar was left untreated as a control area.
I placed these sampled on a paper towel in an area of my workshop where they would not be disturbed. My workshop is not temperature controlled and is not completely sealed to the weather. I have checked the sample from time to time and have never noticed any corrosion. It is now about six months since I started the test and I felt enough time has past. I used a paper towel to remove the lube so I could examine the surface of the samples. The results are shown in the photo below. I can see no corrosion on any of the samples, even the surfaces exposed to pure stearic acid. Now this is not to refute anybody else's experience with Stearic acid. The procedures each of us use to make our lube and the materials we choose to use could be different in some way and we could get different results. What I have found, at least in my case, is that the stearic acid did not cause any issues.