Galvanic rust ?

[Ludington]

I changed out my submersible pump a couple years back and I always wondered if what I found could be galvanic rust. My pump was stainless, but I'm sure the nipple was something else.
It just seemed like a lot to be rust. It looked more like a bunch of red clay / mud build up around the connection. Allthough, I'm not sure how that would happen. But take a look at the picture and tell me what you think. The new pump is plastic where it connects so uf it was rust it shouldn't be happening again. Just an irritation in the back of my head.
What do you think this is?

 

[Twowaxhack]

If the piping was steel then it’s rust

 

[Ludington]

If the piping was steel then it’s rust

That was quick, thanks ! It wasn't mushy or slimy like mud would be, it broke off in chunks.
We were in such a hurry to get the new pump back down the hole, we just unscrewed the old and screwed the new one on. The nipple looked fine, no pits, nothing to physically show a problem. but it was probably compromised in some way.
Hopfully it stays intacted until the next pump is needed. At least with the top of the new pump being plastic. It shouldn't progress.

 

[Valveman]

Very common to see that rust from dissimilar metals screwed together at the pump. Yes it is electrolysis. Tape over the fittings with electric tape and they will look brand new 30 years from now. If not, it can eat a hole in the fitting in as little as 6 months.

 

[Ludington]

Very common to see that rust from dissimilar metals screwed together at the pump. Yes it is electrolysis. Tape over the fittings with electric tape and they will look brand new 30 years from now. If not, it can eat a hole in the fitting in as little as 6 months.

Thanks Valveman,
Being the pump was changed and has a plastic top, no more dissimilar metals touching.
That picture was taken August of 22, so commi g up on 2 years of the new pump being in the well with no troubles yet. I would expect if a hole had developed that we didn't see, it would take longer and longer for the pump to get up to pressure. (Something to watch for) or a slow leakage of pressure once it stopped. So far no troubles, maybe I doged a bullet (for now)