Blasting Garnet - What Grade?

[Citroënbender]

If the main task is cleaning up chassis and subframe parts (forged, cast, pressed ferrous) with some age/weathering, what’s the suggested grade of garnet for blasting prior to new paint?

[roKWiz]

Blasted our 6mm plate hull with 30/60 80 grade garnet, would be a suitable for a little heavier steel, like a truck chassis if that's all you were using it for.

Brown aluminium oxide is a lighter grade for surface prep.

Boatyard supplier was Blastone in Silverwater don't know if they are still around.

Most boatyards have all gone to beadblasting lately.

[Citroënbender]

Unfortunately, Blastone (now in Wetherill Park) only do 2 tonne bags of 30/60.

Will give this grade a try with a 25kg bag from Hare & Forbes.