Hmmm.. got me thinking, Mick. (memory is going) I think it was powder coating.
What does this look like @Crashalot
View attachment 135469
Been on about 15 to 18 months and still look great. No bother with heat yet.
One of my rear pistons I couldn't get out, so would have been a waste blasting and painting if I hadn't checked first.
Yeah still nice and bright as long as they key the surface (media/husk or glass )you will get a good Finnish. .glass is the best as it's not so harsh that it pits the surface as the glass compresses and breaks down unlike something like iron ore grit which can wear the alloy away in front of your eyes ...wasting your time powdering them if you can't clean them first ..