Corrosion test

I have seen some much about the corrosiveness of Pyrodex that I thought I might do my own test. I selected 3 samples of mild steel, .25" X 1" X 3":



After touching each with the random orbit sander and cleaning with solvent, I charged them with a 44 Mag case full of powder; 1 each Graf's, Pyro RS and Triple 7, and touched off with a lit straw:



Each piece of steel received two charges of the designated powder with no cleaning between. Remarkable difference between the three. BP went with a single quick "woooosh", and the Pyro and Trip7 fizzled for a few seconds.

After burning a double charge on each, I placed all three pieces of steel in my garage to "age" for a few days. My garage - located not too far from the ocean in eastern NC - is by my estimation the most humid place on earth.

I can't wait to see what happens next.

Great test! Please be so kind as to share the pictures of the results with us! :thumbsup:

Would not be worth doing if I did not share!

I'll look forward to the results. My guess is that all three will be a mess! Geo. T.

Already some rust forming on the BP and Pyro after a couple hours. Can't wait to see myself.

Don't get it on your clothes!

I would recommend taking a picture each day, this way you could see the progression of rust and show what happens to a barrel thats not cleaned in a timely fashion. A close-up shot of the metal after it has been cleaned with soap & water and a soft brush will show the pitting that can happen when ones M.L. is not cleaned properly. Test will also display visually that when substitute powders are used, they too will rust a barrel unless cleaned in a timely fashion. :v

About 22 hours in....obvious signs of corrosion on the BP and Pyrodex samples. Not sure how much justice the pictures do. It looks to be very reddish brown under the fouling.

Graf's 3f:



Pyro RS:



Trip7:

From what I can see it appears as though the BP has the most corrosion followed by a little with the Pyrodex, yet I don't see anything noteworthy on the one with T7. Is that correct?

I've noticed nothing that looks like rust on the Triple 7 sample. It's a toss up between the BP and Pyrodex. In person they both look about equally corroded. They were both rusting within 4 hours.

Good test,
I "control" piece should have been set up too, a blank piece prepped just the same and nothing done to it. That would determine how a plain piece would rust.
Some cardboard between the pieces would have been nice when the burn occurred, something to prevent even minor cross contamination,
But hind sight is 20-20, :idunno:

I do have a control piece, it just did not fit on the board. I think you're right about the dividers, or even more space between the charges, though.

Good test. Fun to follow. Thanks for doing it.

Did you cover the pieces to prevent cross contamination?
I.E. cover two then flash the powder on one. Then cover the first and uncover another and flash it then cover the two flashed and flash the third?
If not the test is meaningless since they are all contaminated with elements from the other powders.
In corrosiveness worst to least its generally Pyrodex, BP, then T7 which is largely if not completely non-corrosive.
Pyrodex also tends to pit deeper than BP does.

Dan

You didn't read this topic did you?

I am sorry you find it meaningless. Though there was a little more 'poof' than I expected, and have previously mentioned I should have accounted for it in advance, in my opinion there really is not enough potential for cross contamination to render the whole ordeal meaningless. Besides, it's just me having a little fun in my garage and that's all I really need.

Good test and now it's time to sand off the corrosion and start another.

Might I suggest (like others) separate the samples to prevent cross contamination.

Then apply several types of patch lube under the powder to see what effect the most common lubes have upon the corrosion rate.

In my experience different lubes have an effect on the fouling and it would be interesting to see what effect they have on corrosion as well. I would do it but the only powder I have is real black. :bow:

Maybe it's time you get some then, as I will not be sanding it off and starting over because you say so.

I cannot believe how abrasive some people can be over something they have nothing to do with.

If anyone does care to see the results of the test - that's not quite good enough for some people - feel free to drop me a line at [email protected].

Thanks.

Well, I think it's of value. So what if it isn't a rigidly scientific approach, I don't think that was your intention. It's still more information than most had before you did it.

I did a similar thing a while ago, when I was messing around with lube mixes. I cleaned a steel bar, applied several of the mixes and left it out in the rain (by coincidence it rained constantly for the next day or so).

They all allowed rusting to occur! At the end of the day I'm not quite sure what I proved :hmm: .

I'm sorry that you took my suggestion as being abrasive...if I had intended it to be, there would have been no doubt. Guess you missed the part about a good test. I'm not about to go out and buy a bunch of different powders that I'll never put down the bore.