Metal finishing Q&As since 1989

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Metallizing on Mild Steel

I run a small fabrication unit and I happened to hear about shot blasting and grit blasting . Are these terms different from each other . If so What is the difference between the two. Also I read through metallising in many of the surface preparation sites but couldn't understand whether such metallising can be done on MS material and what is the use of it.

Rekha Sekhar
hobbyist - Haryan
May 11, 2011

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May 11, 2011

Hi, Rekha.

"Blasting" means impelling particles at a surface with sufficient velocity and energy that when they hit the surface they tend to remove whatever is on it, be it scale, paint, plating, or whatever. The particles can be sand, glass beads, steel shot, grits of different sorts, dry ice, etc., etc. Depending on their size and hardness, and possibly other factors, they will have varying effects on the surface.

"metallizing" is slang -- an inexact shortcut term to describe a process that actually requires more words to describe it; and slang terms therefore probably mean different things to different people under different situations. The most common usage in my own experience refers to putting a metallic (usually conductive) surface onto a component that was not metallic (and probably was non-conductive). To me, in my limited experience, metallizing of mild steel wouldn't make semantic sense.

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

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May 16, 2011

Dear Rekha,

I would suggest that metallising in the context that you have read it alongside blasting would be the process that is also sometimes called metal spraying or thermal spraying.

The process melts metals (and in some cases ceramics) that is then sprayed as a coating onto a substrate. Contrary to the above answer, it is very commonly sprayed onto mild steel. One of the biggest applications for the process is spraying zinc or aluminium onto mild steel to give a corrosion protective layer.

Prior to spraying, the surface must be grit blasted to give a key for the metal coating to adhere to. Stuart.

Stuart Milton
- Dudley, West Midlands, UK

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Thanks, Stuart.

Yes, zinc or aluminum can beneficially be coated onto steel by a wide variety of processes including metal spraying. Considering the overall inquiry I probably should have recognized that in this context metallising referred to metal spraying. Thanks again.

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
May 16, 2011

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Thank You For clearing my confusion but another question that arises is whether such metal spraying can cause any sort of environmental pollution and how such a factor can be prevented.

Rekha Sekhar
- India
May 18, 2011