[Winold]

A steel brush does not damage (cast) iron, steel or stainless, it only cleans it from paint and rust. Do not use a steel brush for aluminium or copper, it will damage that. Use a brass brush for these softer metals or be very carefull and gentle with a (thin wired) steel brush on it.

[Winold]

Hi Thomas,

I've found that solid brass (rotating) brushes leave a brassy stain on (some) metals. Try a steel brush, see what that does. Most likely you'll brush off the brass colour and see clean metal. I'm not sure what metal the barrel is made of. It is a cast iron, but they've used a big variety of recipies for various types of cast iron, all with their own specs in strength. Wonder what pops up when you use a steel brush.

Cheers Winold

[Thomas]

I cleaned some fins with a brass brush and found this colour there as well. I am pretty sure that it is not a remnant of a repair.

[klaudius]

Good Morning
Is safe cast iron. Think was repaired with silver solder.
Greetings from Germany
Claudius

[phutton]

Not certain, but I suspect it is a nickel iron

[Thomas]

Is that really cast iron...