G'day FC,
Vapour blasting, water abrasive blasting, aqua blasting (and probably other names) is essentially abrasives carried in water and directed at the object to be restored under pressure delivered by pumps within the machine (to activate the mixture through the machine) and high pressure air (to give the mixture the required speed to get the required finish) .
Most blasting materials can be used but my machine is dedicated to glass bead only - sand is way too harsh for alloys and given the range of abrasives available (esp aluminium oxide and garnet) doubt too many would use it and if they do it is a dry cabinet or room.
Steel shot peening is also used but primarily for surface stabilisation eg con rods etc and is also done in a dedicated cabinet.
I choose to only use glass bead as it gives a fantastic finish and by only using one type of blasting material the finish is consistent although I am looking at a couple of options that are compatable. The machine also has a soluble cleaning agent in the solution so the surface comes out very clean and far less aggressive to the metal be it an alloy or steel.
The finish on cast products such as manifolds has to be seen to be believed. Compared to dry blasting oil and grime can be easily wiped off as the surface is far more stable. When you look at the surface of the blasted metal under an engineers microscope you see a whole lot of sherical depressions overlapping whereas when you look at a dry bead blast finish you see a lot of jagged cratering caused by beads shattering on impact. Water blasting minimises this as the water and additives cushion the bead on impact. Pity I don't know how to post pics on here or could show some before and afters.
Check out this dude in the UK - a good site.
http://icmhome.org.uk/index.htmlWet bead blasting over dry blasting (which I used to do but now use that machine for aluminium oxide mainly on steel items) has the advantage of less impregnation of the surface and minimal residue in holes but for the most part common sense dictates they be plugged.
Without getting into a slanging match here the water blasting generally achieves a superior finish to soda blasting but for me soda blasting is the ideal for whole of panel blasting etc (besides while my machine is a good size panel etc are too big for it) as it is far less aggressive than dry blasting of panels.
SAFETY NOTE - On the subject of sand (which is now illegal as a commercial blasting medium).
If you do use sand in say a small hand-held gun to do rust spotting etc RESPIRATORY PROTECTION (air supplied respirator with a hood or a helmet and visor) MUST MUST MUST be worn. When normal sand impacts to powder it creates a dangerous dust which will cause silicosis - google it - bad shit!
Sorry for a long winded answer but I have had a few inquiries! Hope this helps.
Dave Mac
