Copper Etching

Posted by Prof. Boris Van Galvin on 25 June 2009 | 0 Comments

After several evilgenius meetings we realised the need to create a badge of honor that could be worn as a symbol of our dedication to the cause. After much experamentation and the application of a bit of science a process was found that not only produces great results but can be reproduced with reasonably predictable outcome.

My first thoughts were to use Ferric Chloride however this has apparently been tanek off the market in New Zealand and the replacement chemical is a on shot etch solution. To be honest I have made home brew that could etch better than that stuff.

I then discovered a few posts by varous people how have used Cupric Acid to etch circut boards and as i was also intending on doign the same for another project felt that it was an ideal test.

To create the etch solution I used Hydrochloric Acid and Hydrogen Peroxide. Care must be taken not to inhale the fumes as they are definatly not good for you but then the same applies to salt water hydrolisys.

The 6% Hydrogen Peroxide was purchased from our local chemist and 30~40% Hydrochloric from our local pool supply company. I Measure 2 Parts Hydrogen Peroxide in to a NON METALIC container then added 1 Part Hydrochloric (ADD ACID TO WATER) so Hydrogen Peroxide first as its mostly water and Hydrochloric last.

For my first test I used a section of the graphical background used by another Evilgenius (Mjr. Pisht) for his business cards then transferred that to the copper.

The results were great. I compleated two etchings one of the postive image and the other inverted

By this time one of the crew had finished the artwork for the badge and since i now knew that the etch procees worked it was just a matter of deciding if the badge looked better as a negotive or posotive releife.

 

I later produced the gauge background for the darwin gun using the same method, from memory the lettering is well under 2mm high. The mottled colour was caused by oxydising the peice after it was etched and not danding/polishing it.

Although I did not have enough time to complete a nice test peice in Brass i did grab a feltpen (water resistant) and scribled on a peice of brass then etched it with the following results. Apologies for the light glare.

 Larger images are posted in the gallery.
http://www.evilgenius.net.nz/gallery/album/Copper-Etching