Engraving on metal compound $20 for one year

[Scott Shepherd]

Looks kinda splotchy to me. Does it always look like that? Looks overpowered too, letters running together. Is that the normal look?

[Sergio Arze]

Looks kinda splotchy to me. Does it always look like that? Looks overpowered too, letters running together. Is that the normal look?

the letters can be sharper if you dilute the Plaster with alcohol and spray it, but most people don't have the equipment to spray.

[Mike Milli]

Looks kinda splotchy to me. Does it always look like that? Looks overpowered too, letters running together. Is that the normal look?

My company name and trademark was reduced way down from a large file for other use. I tried the same file, and the same ratio on other material and got the same results. The ".223 Remington" script is quite crisp and clean. It may not look like it in the photo, but it looks really great when you have it in your hands.

Just to give you an idea of the size and scale, the stainless piece is about .920" in diameter, and the print is about .150" high. The print that looks to run together below my company name "Bemidji, MN." is only perhaps .020" high.

As I have stated earlier, I am brand new to this forum and to laser engraving. I am not new to firearms, and the ".223 Remington" print, or any print of that quality would look good on any firearm.

[Dan Hintz]

what I really like about the formula is not that it just marks the steel but it actually engraves into it.

I think this may be an illusion due to the thickness of the coating... you're not engraving into the metal, you're adding a thin layer on top.

[Sergio Arze]

I think this may be an illusion due to the thickness of the coating... you're not engraving into the metal, you're adding a thin layer on top.

Try out the compound and you will see that the metal actually get's engraved. This is not a marking solution, did you notice that this allows you to cut aluminum foil? , so it is very clear this is not an "illusion". Dan I can understand your doubt but you really need to try it!

[Mike Milli]

I think this may be an illusion due to the thickness of the coating... you're not engraving into the metal, you're adding a thin layer on top.

Dan, you can theorize all you want, but it IS engraved into the metal. I have held the part in my hand, and have inspected it carefully under magnification, trust me, the marking is not laying on the surface.

[Dan Hintz]

Okay, I'll spend some time (later today, maybe?) thinking about the possible chemistry involved, see what I come up with. I'm open to the possibility it is etching by chemical means, I was doubting it strictly from a laser point of view... need to keep my mind open on this one. Calcium sulfate and stainless, hmmm....

[Dee Gallo]

Dan,

I tried this mixture (Mother's and plaster) - and did not use my airbrush, just put it on thin in some spots, thick in others to see what would happen. I did my experiment on the bottom of a cheap pie tin and it actually cut (with raster-only settings) through the pie tin in one spot where the mixture was very thin. Where the mixture was thick, it etched the metal leaving a "feelable" roughness. It could be color filled, I think.

I'm still not sure if I like the looks of it, the white image on silver metal is a bit too ghostly, but it does work. It would be useful if you wanted a subtle background image and then cermarked over it for 2 different effects, or used the white for letters with a darker outline, etc. It might even be cool to invert a photo, make the white, then use cermark to make the grays and blacks.

One comment about the permanence factor: yes, rubbing did not remove it, but I put some permanent marker on it to see what would happen, then wiped it with De-Solve it (citrus non-water cleaner) and the whole thing wiped off the pie tin. The lightest areas disappeared completely, the deeper etched areas left a faint ghost and you could still feel the roughness. If I had used paint, the color fill would have stayed.

If I get time, I'd like to apply it with an airbrush for more control and try different settings. This process shows promise, but we would have to figure out the best use for it. I wonder what it would do on colored metals, such as brass, copper or gold. That's next!

cheers, dee

[Dan Hintz]

Here's my initial thought on the (possible) chemical reaction going on for stainless steel (warning, mild chemistry coming up):

There is a vast array of possible stainless formulas, but I believe the basic formula is of most importance (i.e., the chromium content). Just as everyone is used to a dull oxide layer on aluminum preventing it from "rusting" further, stainless also has such a passivation layer (luckily, it's so thin it's completely transparent, for all intents and purposes, so we can see the pretty steel underneath), Chromium (III) Oxide. When that's combined with the Calcium Sulfate (the plaster) along with the heat of the laser (and I'm betting water vapor from the air), you get Calcium Oxide and Chromium Sulfate. I believe it's that Chromium Sulfate which is providing the mark, and the Calcium Oxide is blown/wiped away.

This is only an edumacated guess on my part as it has been quite a few years since I attacked chemistry with any gusto. I cannot say if the Chromium Sulfate will retard staining like the Oxide did, but it is probably irrelevant due to the color/contrast.

The actual formula is this:
3(CaSO4) + Cr2O3 + heat + 12(H2O) --> 3(CaO) + Cr2(SO4)3 *12(H2O)

[douglas rubio]

why do you guys even bother with this, you can buy Cermark and will give you black marks on metals.

[Dan Hintz]

why do you guys even bother with this, you can buy Cermark and will give you black marks on metals.

Well, let me think about this...
1) 250g bottle of Cermark for $140 shipped
2) 10,000 gram bottle mixed myself for about $7 in supplies.

Tough call...

[Dan Hintz]

The actual formula is this:
3(CaSO4) + Cr2O3 + heat + 12(H2O) --> 3(CaO) + Cr2(SO4)3 *12(H2O)

Meant to add... the above was the hydrated version of Chromium (III). For aluminum, the process would be the same, except replace the Chromium Oxide (Cr2O3) with Aluminum Oxide (Al2O3), creating Aluminum Sulfate (Al2(SO4)3).

3(CaSO4) + Al2O3 + heat --> 3(CaO) + Al2(SO4)3
(I'm showing the anhydrous form here as it does not alter the main content, but I cannot say offhand which form is actually attached to the aluminum).

[Anthony Scira]

Meant to add... the above was the hydrated version of Chromium (III). For aluminum, the process would be the same, except replace the Chromium Oxide (Cr2O3) with Aluminum Oxide (Al2O3), creating Aluminum Sulfate (Al2(SO4)3).

3(CaSO4) + Al2O3 + heat --> 3(CaO) + Al2(SO4)3
(I'm showing the anhydrous form here as it does not alter the main content, but I cannot say offhand which form is actually attached to the aluminum).

Check out the BIG brain on Dan ! ! !

(sorry Pulp Fiction reference)

[Dan Hintz]

I like to consider it a small brain that enjoys thinking big

I'm still questioning if the material is actually being etched into or not. All of the above happens with the outer oxide coating, something that doesn't exist once the thin thin thin top layer has been removed. Once through that layer, there's not enough oxygen to continue creating the oxide.

As far as cutting of the thin aluminum goes, I'm wondering if the coating is allowing enough heat to be centralized and cutting it via melting (bare metal just reflects too much of the far-IR wavelength energy to cut it, why near-IR YAG wavelengths are so good at it)... proof of this might be found by using another IR-opaque material that is relatively inert to the oxide layer, which would allow heat to build up. If the aluminum foil is still cut, that proves a good way to cut thin metals and says the chemical reaction with the plaster is strictly surface-based. If it's not cut, it proves the plaster is etching deep.

This will certainly be a fun series of experiments...

[Mark Ross]

If it cuts various foils, this means thin detailed metal inlay possibilities...cool...