Turns out 7075 takes longer than CPU heatsinks to etch to the same depth. Will increase etching time when we do the Fire/Safe markings. Overall I’m very pleased with the outcome.

First attempt at electro-etching my son\’s lower receiver. This setup has failed the leak test twice now and we may abandon the popsicle sticks + hot glue, and use polymer clay to create a well to retain the electrolyte (table salt and water, with a dash of vinegar) We did some tests on old computer CPU heatsinks with the Q-Tip method and while…Read More

😁😁

Picked up an AR 15 Lower Parts Kit and buffer tube kit at the Hannibal Gun Show. Other than some trouble with the trigger guard and a floppy safety selector (80% lower, could be the maker) everything came together just fine.
Hope to see everyone Sunday, bring out your ambi safeties, and enhanced trigger guards.

Actual build photos