Posted by duncan webster on 14/09/2018 20:14:01:
I have a recipe given to me 40 years ago for a witch's brew containing sodium nitrite and caustic soda (from memory).
….
I'm assuming it is steel, if cast iron all bets are off.
By 'eck – it's a non-shooter, but at first I wondered if you were suggesting some sort of fiendish propellant… ![surprise surprise](data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw==)
Yes, it's plain BDMS, allegedly EN1a, though it's not quite as free- and clean-machining as some I've had.
As for Vic's sandblasting – isn't that likely to give a matt finish?
The other cannon in my album was also turned from BDMS, washed in near-boiling detergent water immediately prior to applying G96 paste, then washed again, oiled and polished. That produced a glossy finish that's lasted 16 years with little maintenance.