garnet abrasive
garnet abrasive
(OP)
Greetings
We will use garnet for sandblasting stainless steel. How much iron oxide is allowable percentage of garnet? The high percentage of the oxide can be harmful to stainless steel surfaces or no? Question for me is whether the chemical composition of garnet used as an abrasive in sandblasting stainless important? How much is this composition?
We will use garnet for sandblasting stainless steel. How much iron oxide is allowable percentage of garnet? The high percentage of the oxide can be harmful to stainless steel surfaces or no? Question for me is whether the chemical composition of garnet used as an abrasive in sandblasting stainless important? How much is this composition?





RE: garnet abrasive
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Plymouth Tube
RE: garnet abrasive
RE: garnet abrasive
Even the small particles of SS that it will pick up are detrimental to the surface.
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Plymouth Tube
RE: garnet abrasive
Garnet is used as an abrasive. Per Wikipedia, Garnet refers to a class of minerals known as nesosilicates that has a crystal structure represented by X2Y3(SiO4)3, where X is a divalent metal ion and Y is a trivalent one. The differences in the various types of garnet depents on whether the divalent ions are Mg, Ca, Fe, etc... and the Trivalent ones are Cr, Al, Fe, etc... (iron exists in both divalent and trivalent states). Perhaps I am just getting confused between the term "iron oxide" and "oxidation state of iron".
My take on the question in the OP is whether or not clean, uncontaminated garnet can be used for sandblasting stainless steel. That is, does it matter if the garnet is Almandine [Fe3Al2(SiO4)3] or Pyrope [Mg3Al2(SiO4)3], ignoring for the moment that all naturally occuring garnets will have some of the either divalent or trivalent oxidation states replaced by iron just due to the natural abundance of iron. Since the Almadine contains iron in the Fe+2 oxidation state, it contains iron oxide. Is there a level at which this would be accepatble or must only Pyrope be used?
I don't have a clue, but I don't believe the OP is asking how much iron oxide contaminaiton is permissible before he has to change out his media, but, rather, can garnet be used to clean SS? And, if it can, is there a limit on the (natural occuring) iron content of the garnet that can be used?
rp
RE: garnet abrasive
Steve Jones
Corrosion Management Consultant
http://www.linkedin.com/pub/8/83b/b04
All answers are personal opinions only and are in no way connected with any employer.
RE: garnet abrasive
NATO CODE – S-1738 the sandblast recommended material for cleaning of stainless steels is "Aluminum Oxide" why use Garnet instead?
Here is a quote from the spec:
A.3.6 Application on stainless steels. Preclean the surfaces to be coated with aliphatic naphtha or any environmentally safe cleaner that sufficiently cleans surfaces to pass ASTM F22, but does not harm the surface (i.e. hydrogen embrittlement, etc.). Sandblast the surfaces with 120 grit aluminum oxide. Passivate the surfaces in accordance with ASTM A967, nitric 1, nitric 2 or nitric 3 as applicable.