- Can I get an etch .5 - 1mm deep (using nitric acid)?
- Do I need to periodically add more resist to the inside edge
of the etched area?
- How long can I expect it to take to etch this deep?
Any help would be greatly appreciated.
That depth should be posible. I have never added more resist
when etching silver, It is important to brush the etching with
a feather to clear away the bubles and residue that builds up.
I have found that sometimes their is a residue buildup around
the edges that acts as a resist and can sometimes result in a
step like efect on the edge. What I mean by step like is, part
of the original edge line is etched, then because of some kind
of build up that is not brushed away, the inside edge is
extended in ward, so their is a downward like step created. I
hope that makes sence. In my experiance I have found the bath
strength, and freshness(amount of metal already disolved in the
bath) to be big determanants of how long it will take to etch.
I usualy etch copper, and most of the time I use ferric cloride
for that so I can not give you a good ansewr on how long it will
take. When using nitric I like to brush my etchings with the
feather at least every five minutes, but that could be to much
or to little I don't know. Be very carful not to splash any
acid when brushing the etching. I am not a chemist and realy
know very little about chemistry, so I could be wrong. As
always when working with acid, add acid to water NOT WATER TO
ACID, wear rubber gloves, an apron some eye protection an have a
box of baking soda handy to neutralize acid spills. And excelant
ventaliation is also esental!! Good Luck