I finally got to try Bushy’s brass cleaning formula consisting of 1 cup of water, 1 cup of white vinegar, 1 tablespoon of salt and 1 tablespoon of dishwashing detergent (I used “Dawn”). He had warned that you shouldn’t leave the cases in the solution for too long as it caused some pink spots on the case and could possibly damage the brass. I was curious about the solution’s effect so I conducted an experiment to see what damage it might do and how long it might take.
I had some cases that had been picked up on the range after considerable exposure to the elements. Some of them actually had “mud dobber” nests built inside them. I had soaked the cases in soapy water to remove the bugs but they had no other cleaning before trying this cleaning solution.
For my test I used ten cases, all from the same manufacturer, and they were treated as follows:
1. Control, nothing done to clean it.
2. Tumbled clean only for three hours, using walnut hull.
3. Soaked for 15 minutes, rinsed with warm water, dried and tumbled for three hours.
4. Soaked for 30 minutes then rinsed with warm water and dried.
5. Soaked for 45 minutes then rinsed with warm water and dried.
6. Soaked for 60 minutes then rinsed with warm water and dried.
7. Soaked for 75 minutes then rinsed with warm water and dried.
8. Soaked for 90 minutes then rinsed with warm water and dried.
9. Soaked for 105 minutes then rinsed with warm water and dried.
10. Soaked for 120 minutes then rinsed with warm water and dried.
The tumbled-only case did not get clean, but the tarnish was shiny! All of the cases that were soaked looked pretty good but there were still some visible dark spots on them. The case that was soaked and tumbled looked OK. The pink discoloration that was mentioned earlier was visible and increased slightly the longer the case was soaked.
After the cleaning process I wanted to see if the brass had become brittle from the soaking. I lubricated and sized each case in an RCBS sizing die. I used an RCBS expander die to bell the case mouth a little more than I normally would to see if any case mouths split. None did.
Then I got wondering how quickly the solution could work. I did another batch of six cases and used a two minute interval. I found that most of the tarnish was removed in about 2 minutes and it was pretty clean at 4 minutes. The pink color was first seen on the case that was soaked for 6 minutes. The photo shows the un-cleaned “control” case with the cases that were soaked for 2, 4, 6, 8,10 and 12 minutes.
About this time I thought “what the heck” and soaked a case for 24 hours. It looked bleached out and was definitely harder to size! The photos below show how etched the surface was. Notice how pink the base got. However it didn’t split in the sizing/expanding test.
A final test would be to load and shoot the cases to check for splitting but I really didn’t have the time for that.
One big concern I have is that, with cases that have not been deprimed, some of the solution could get trapped in the primer pocket and do some damage if left there very long.
Normally I don’t pick up used brass at the range unless I know that it is “once fired” factory stuff. Otherwise I don’t really know how often the cases have been used or how hot the loads may have been. However even the cases I have stashed can get tarnished over time. Normally that doesn’t bother me too much as long as I don’t see any pitting.
Based on this experiment I think I would use this solution in the following manner: deprime the cases with a universal deprimer, soak for about 5 minutes, rinse well with hot water, dry thoroughly then tumble as usual.
This wasn’t a very scientific test but hopefully you can get something useful out of it. I had fun messing with it and playing with the camera’s macro features!