View Single Post
  #19  
Old March 15th 06, 04:09 PM posted to rec.aviation.homebuilt
external usenet poster
 
Posts: n/a
Default More LED's - Again


RST Engineering wrote:

Now you can etch the board in the usual way.


Or you can use the new, improved way without that nasty ferric chloride.
Plain old swimming pool etchant (muriatic acid -- 28% HCl) from the home
store plus plain old hydrogen peroxide (3%) from the drug store mixed 2:1
respectively does an admirable job at room temperature. Plus, when you get
done, you have metallic copper (not a hazmat), hydrochloric acid (not a
hazmat), and the hydrogen peroxide which, within half an hour, has broken
down into oxygen (which has escaped into the air) and water. If you want to
be totally environmentally friendly, you can neutralize the HCl with baking
soda ($5.99 for ten pounds at the Charlie's Club places) before pouring it
down the sink.


Ferric Chloride may be safer than Muratic Acid

http://www.artmondo.net/printworks/articles/ferric.htm
Spent ferric chloride can be neutralized with soda as well.

Plus, I THIINK Ferric Chloride is the commonly available de-smuting
solution you need to anodize 2000 series aluminum.

For dyeing anodized aluminum, try RIT, or page through this catalog:
http://dharmatrading.com/html/eng/2934904-AA.shtml Sealing, I guess
you'll have to use clear lacquer.