Electro Etching an AR-15 80% lower.

[VaderSpade]

I think I have this figured out. It is slow going, but cheaper than a CNC.

[krazy]

That'd be awesome! Do post pics! Rhodium solution is expensive as is, i cant believe how much precious metal prices have gone up. Good for our business though, which is weird.

[VaderSpade]

Well I think I got this whipped.

Here's the latest;
The markings seem as deep as any store bought lower (they are deeper than they look in the photos). This is as deep as I can make them with these stencils. The dots in the a's and e's start to lift off at this point. I have some fine jewelry tools; I may mess around with making the serial numbers a little deeper. It should be easy to follow what's here.

I put the name and city to the right above the selector.


Driver’s side.


Passenger’s side.

[Rukus]

Looks great VS! Makes me wish I had the tools to do my own 80%

[VaderSpade]

A few tips in response to some questions I've received.

A cheap NON automatic automobile battery charger 12 volt, 10 amp should work fine.

An automatic automobile battery charger would read a dead short and turn itself off.

One thing I learned the hard way is that the positive side needs to be connected to the lower and the negative side to the Q-Tip. I got it backward once and it ate away the clip holding the Q-Tip, and barely marked the work piece (in this case just a piece of scrap).

If the bare clip touches bare metal there will be sparks, tape off the surrounding area.

I recommend testing any setup on a piece of scrap before trying it on a lower.

If I have the time, and you post pictures of the results here I will cut a few stencils if you have an 80% ready to go. I don't want to be cutting stencils for anyone that MAY one day want to mark a lower.
Priority will be given to builders that have shared there knowledge and experience here on the boards.

I will cut text only (no time for art work). PM for details, but note that deer season starts on Sept. 19th, and I plan to spend all my extra time hunting, so I will need to squeeze this in.

At some point in the near future I will post pictures and instructions on how to place and "weed" the stencils. You will need VERY strong reading glasses.

Example of text;

Manufacture
City State
Model
Caliber
serial #

Max is 10 maybe 12 letters/numbers per line.

If you want room for art work the Manufacture and city should be moved to above the hammer pin/selector area.

[FJKernel]

I think I have this figured out. It is slow going, but cheaper than a CNC.

Hey look, another use for the mag well plug!

Looks great Vader! Good use of the 7075 scrap too.

[JagerTroop]

Nice job Vader.

I recently did some etching on a friends revolver. This technique works on brass as well, but I modified the electrolyte solution a little (saltwater and vinegar). check it out. It looks a little pitted, but in person it looks great. The macro function on my camera picks up more detail than the naked eye.

[Grumpyoldretiredcop]

Finally got mine etched tonight, thanks to VaderSpade. Should look pretty good after cleanup. I used a 12 volt, 0.75 amp power supply from my junkbox.

[MrNiceGuy]

That's awesome work Grump!
Did you use a stencil or photo resist paper?
The Q-tip method right?
What was the salt to water ratio?
I plan to do mine this weekend......want to make sure I don't screw it up.

[Grumpyoldretiredcop]

Used a vinyl stencil that VaderSpade was kind enough to make up for me and the Q-tip method, although I used regular vinegar instead of white (that's what I had on hand). About 1/2 teaspoon of salt in a 3-ounce cup of vinegar. I washed the receiver in detergent afterwards, followed by spraying with contact cleaner to ensure that no acid residue remained.

Note: That vinegar/salt mix will eat the bottom out of a 3-ounce Dixie cup in a couple of hours. My workbench might never be the same - it'll certainly never smell quite the same...

[VaderSpade]

Note: That vinegar/salt mix will eat the bottom out of a 3-ounce Dixie cup in a couple of hours. My workbench might never be the same - it'll certainly never smell quite the same...

I just learned on Saturday that it will also eat a spoon that was left in a glass. It was a silver plated spoon and the plating was left behind, and was quite thick, so I filed this fact away as a good way to recover silver. Then I had a little fun. My girlfriend made her famous “killer chili” for the Super bowl, I palmed the half eaten spoon, when she turned away I dipped it in the chili and pulled it out as she turned back. What did you put in this stuff I asked???

[goober]

lol nice trick

[sv_1]

What did you do to get that finish on the aluminum?

[VaderSpade]

What did you do to get that finish on the aluminum?

Blasted with glass beads in a cheap Harbor Freight blast cabinet.

I have since learned blasting is not necessary if you etch before anodizing. Etching leave a nicer finish.

[goober]

Blasted with glass beads in a cheap Harbor Freight blast cabinet.

I have since learned blasting is not necessary if you etch before anodizing. Etching leave a nicer finish.

yup. 30 seconds to a few minutes in some NaOH (lye) will produce a nice matte surface after ano & dye, providing the part has been prepped, with all blemishes and undesirable surface imperfections smoothed out. ano does not hide anything.
parts must be CLEAN and OIL FREE.
its a good practice to desmut in a ferric acid based solution after etch, especially for some alloys w/ lots of non-Al content such as 2024. not absolutely vital for 6000 & 7000 series alloys, but won't hurt.
always DI rinse between baths! and keep part wet/submerged in DI if it will not go directly into next bath after rinse.