Oxidizing aluminum

[Gary Hair]

I have some oxidizer that I bought a while back and it works really well. I have a customer that wants to oxidize lots of aluminum parts after I laser them. Does anyone know what it's made from and if it's possible to make my own? It's just a chemical process but I can't find anything that says what chemicals.


Thanks for any help!


Gary

[Braden Todd]

Not to sure on the product but maybe caswellplating.com will have some answers for you. I use them for Electroforming supplies and I saw they also sell anodizing supplies, maybe they'll have oxidizing supplies too.

Good luck

[Matt Turner (physics)]

Do you have a brand name or anything? You might be able to find an MSDS that lists the ingredients.

[Mike Null]

Gary

I've used products from this company for quite a long time. http://epi.com/?gclid=CLC44YbGp8MCFaNj7AodQBAAlA

This is the one I have. http://epi.com/c/black-oxide/aluminum

The local distributor gave me a sample several years ago and when I ran out they gave me another.

[Dan Hintz]

Selenious/selenous acid is one way to blacken, though the stuff is a bit nasty.

One "blackening" solution I just noticed uses a mixture of sodium hydroxide solution (for bite) with some zinc oxide (colorant). There must be other dyes in it, because ZO is white.

EDIT: Looks like Mike beat me to the punch on EPI... they sell the solution I mentioned just above.

[Frank barry]

Hi I worked in a tooling company for many years and we did a lot of back oxidizing and it can be very difficult to get a very black finish also you will need to set up a number of pots to do it I would suggest you sub it out as its a pain cheers Frank

[Dave Sheldrake]

Selenious/selenous acid is one way to blacken, though the stuff is a bit nasty.

One "blackening" solution I just noticed uses a mixture of sodium hydroxide solution (for bite) with some zinc oxide (colorant). There must be other dyes in it, because ZO is white.

EDIT: Looks like Mike beat me to the punch on EPI... they sell the solution I mentioned just above.

Sodium Hydroxide turns zinc oxide black Dan :) it's used in some of the hot dip gun blues / blacks (I used to use it to refinish firearms, nasty nasty though, 130 degrees C so any water gets in and boom!)

[Dan Hintz]

Sodium Hydroxide turns zinc oxide black Dan :)

Hmmm, didn't think about the reaction between the two. My initial thought was the NaOH was being used just as an etchant.

[Mark Sipes]

I don't oxide a lot of Alum but just wondering if these parts are pre-finished with a sealant prior to engraving (lasing). Or if that a step you do also, Gary . I have attempted to darken lasered trophy sheet stock with no results. Have had better results with drag engraving, I guess it exposes fresh alum to the chemicals.

Cermark for anodized alum ? Is there a Power Minimum to achieve results?

.

[Gary Hair]

The parts are anodized and I'm lasering through the anodize layer then oxidizing. The oxidizer I have from Ability Plastics is working fine, it's just a bit expensive for larger scale use. Cermark wouldn't be possible because I'm lasering with my fiber.


I don't oxide a lot of Alum but just wondering if these parts are pre-finished with a sealant prior to engraving (lasing). Or if that a step you do also, Gary . I have attempted to darken lasered trophy sheet stock with no results. Have had better results with drag engraving, I guess it exposes fresh alum to the chemicals.

Cermark for anodized alum ? Is there a Power Minimum to achieve results?

.

[Dan Hintz]

Cermark wouldn't be possible because I'm lasering with my fiber.

Cermark works with fiber just fine...

[Gary Hair]

Let me rephrase that - I'm not using Cermark as much since I have a fiber. Plus, the added time to clean, apply, laser, clean, would never work with these parts. Some of them take 3-4 seconds each and Cermark would add way too much time to the process. They have laborers that could wipe on, or dunk, the oxidizer that would add pennies to the parts where Cermark would add many times that.


Cermark works with fiber just fine...

[Vicki Rivrud]

Hi Gary,
I oxidize silver photo frames after engraving away the coating.

In Jewelry making class I learned about liver of sulfur gel or XL gel also called Patina Gel. A little goes a long way mixed in distilled water or if I am doing a small silver item I'll dab a drop or 2 onto the item with a q-tip. To neutralize the process I then use baking soda & distilled water. If not dark enough I simple wipe black rub-n-buff to brighten the black and then I give it a light spray of Remington Rem oil with Teflon.

I also have found oxidation liquid from Quality Engravers supply at $30.00 but the gel runs me about 14.95 and I mix my own. Try Jewelry supply, Cool Tool even Amazon for the gel.

Hope that helps,
Vicki

Hope that helps

[Mike Null]

Gary

EPI sells in bulk--gallons and drums. It would be cheaper, safer and easier than trying to brew something yourself.

[matthew knott]

Cermark can be used with 'some' fiber lasers, the 'some' being lasers that are able to either run at CW or very high frequencys. The lower budget machines tend to be limited to 20khz to 80khz, at 80khz you still have a fair bit of pulse energy, rather than heating the cermark it just gets blasted away. You can kind of make it work using a long focus lens but its fair from perfect.

[Dan Hintz]

Cermark can be used with 'some' fiber lasers, the 'some' being lasers that are able to either run at CW or very high frequencys. The lower budget machines tend to be limited to 20khz to 80khz, at 80khz you still have a fair bit of pulse energy, rather than heating the cermark it just gets blasted away. You can kind of make it work using a long focus lens but its fair from perfect.

Thermark/Cermark recommends CW or anything >50kHz

[Gary Hair]

Thanks to everyone for your suggestions! I'll pass them along to my customer and let them decide how to proceed.

[Clark Pace]

I have some oxidizer that I bought a while back and it works really well. I have a customer that wants to oxidize lots of aluminum parts after I laser them. Does anyone know what it's made from and if it's possible to make my own? It's just a chemical process but I can't find anything that says what chemicals.


Thanks for any help!


Gary

I didn't think aluminum oxidized? Oops spelt that wrong!

[Vicki Rivrud]

I didn't think aluminum oxidized? Oops spelt that wrong!
Hi Clark,
This is what we have done besides the los https://www.youtube.com/watch?v=VUj5E06HYyg

I was able to purchase a bottle from Fred at Quality Engraving Supplies in CA - not sure how it compares in price to what Mike is recommending but this stuff goes a long way and really blackens the aluminum panels & frames we cut.
Vicki

[Frank barry]

thanks for that it looks super I guess it would work on stainless steel also dose it wear well ? Frank

[Dan Hintz]

I didn't think aluminum oxidized? Oops spelt that wrong!

Aluminum oxides pretty quickly sitting out in the open air...

[Dave Sheldrake]

I didn't think aluminum oxidized? Oops spelt that wrong!

Anodise = aluminium dihydroxide, it's basically staining the oxide combs that form on the aluminium surface :)

[Matt Turner (physics)]

Aluminum oxides pretty quickly sitting out in the open air...

And it oxidizes more thoroughly if you add some gallium and mercury to keep things going: http://youtu.be/lfBfKIHYY2g?t=36s