Hi, apologies if this is in the incorrect section.
I have several aluminium castings that have been sat around for a long time and have all kinds of gunk and stains on them. I usually stick them in the sonic cleaner and this is very effective on general stains and gunk but these are a bit beyond that.
I am fortunate enough to have aquired a blast cabinet which came with `oxide powder` that is very good but seems to leave the castings a bit rough…..ideally I would like something to remove the heavy carbon/grime but leave the original finish which I can then just put in the cleaner to finish.
I have been advised to use walnut shell (not sure which grade though) but am having trouble locating some, does anyone know of any suppliers that they use or know of which are reasonable? The few I have tried want a bulk order and a delivery charge that seems a bit steep.
Many thanks
James.