Engraving Alodine on Aluminum

[Scott Shepherd]

Had a call to engrave some aluminum that has alodine finish. The customer says it's gold. Anyone got any advice? They said they'd bring me a sample to play with. CO2? Fiber? Is it going to remove the alodine or just turn it white like anodizing?

[Gary Hair]

Unless it won't fit or the image is too large, I'm always going to default to the fiber for marking pretty much anything, especially aluminum. I'm not sure how alodine will react but I think you mentioned the only two possibilities - not likely to turn black or some other color besides white or silver. One warning though - alodine is usually used to resist oxidizing and/or as a primer of sorts for painting. Removal may have an affect on the aluminum that may not be ok for your customer.

[Kev Williams]

Alodine, aka chemfilm conversion is just a treatment to seal the aluminum to protect it from corrosion and readies it for primer and paint. I engrave clear chemfilmed parts all the time, you'd never know they were treated with anything, except for the fact the aluminum won't turn your fingers black! :)

The clear doesn't react much if any to a C02 laser, the gold MIGHT go white but I'm thinking not- It's been a LONG time since I engraved any gold alodined alum and IIRC I've always had to tool engrave it--

Chemfilmed aluminum Cermarks just fine if you've has success Cermarking non-treated aluminum before. The Fiber will mark it just fine, but the chemical film will be gone anywhere that fiber hits it...

Both of these are Chemfilmed and Cermarked. Note below 'Aluminum TEST ENGRAVING' you'll see an upside-down shadow of the same engraving- this was all my 80w Triumph could muster by itself.
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