From: REMOVE_THISdwilkins@means.net (Don Wilkins)
Newsgroups: rec.crafts.metalworking
Subject: Re: Etching Stainless Steel
Date: Mon, 06 Jul 1998 15:29:08 GMT

On Sat, 04 Jul 1998 20:18:01 -0600, Jerry S <zepto@mindspring.com>
wrote:

>Dave Harris wrote:
>>
>> Does anyone know of a way to etch or chemically treat stainless steel
>> to give a uniform, matt finish (similar to what you can get by using
>> lye on aluminum, or by sandblasting)? That's probably a dumb question,
>> because SS is made specifically to resist chemical attack, but you
>> never know...
>>
>> Any information would be much appreciated.
>>
>> Thanks,
>> Dave
>
>Aqua Regia will do it. Wicked stuff.
>Aqua Regia consist of one volume of concentrated Nitric acid and
>3 volumes of concentrated hydrochloric acid. Reaction rate
>depends on temperature. Doesn't do much until warmed up. The
>warmer/hotter the faster. Small parts can be immersed in a
>beaker of the stuff and warmed up until the reaction progresses.
>Large parts would be difficult. You can really gobble up the
>material at higher temps. Be careful. Not recommended for the
>faint of heart or careless. Always dispose of waste material
>properly.

Be aware that Aqua Regia will evolve chlorine gas. When heated you get
more chlorine faster. Chlorine can and will do serious damage to the
lungs and eyes. The nitric will raise hell with the skin.

Also not recommended for anyone that doesn't have experience working
with dangerous chemicals. This stuff bites fast.