Reflective materials as well - i.e.: a polished stainless steel knife blade?


#1

Continuing the discussion from Etching Stainless Steel or Titanium?:


Reflective surfaces?
#2

I am interested to hear the answer for this question as well, I do Jewelry so I use silver and would love to engrave my work.


#3

Here is something about this:
http://community.glowforge.com/t/precious-metal-engraving/81

There was also a topic about stainless steel, unfortunately I couldn’t find it quickly. In short: you can’t cut stainless steel but if that is treated with special compound/liquid you can engrave it (there were a short video about it to external web site). Maybe someone can link it in here.

EDIT: Here is the what that I was looking about:


and here is the post; where was the video about it:


#4

The compound that you need for some metals is e.g. “Cermark”.


#5

There is a common misconception going around about engraving vs. marking. Engraving is a subtractive technique…you’re actually removing material by cutting a groove. You absolutely can’t do that in metals with a 40W CO2 laser cutter. You can mark the metals using something like Cermark/Thermark, which leaves a permanent black mark on the surface.

The GF team should clarify this by removing any reference to “engraving” in metals. It’s misleading and seems to be confusing a lot of people.


#6

Agreed - I’m interested in ‘marking’ (logos, text/numbers, ruled lines) on Stainless (polished and brushed).

…and also interested in how the less expensive MolyD approach looks/works v.s the industrial grade Cermark/Thermark.

To clarify the original question, though - I was concerned that a reflective surface (polished stainless) could damage the optics.


#7

The laser loses power rapidly as it defocuses. With a 40W laser you shouldn’t need to worry about reflection damaging your optics…especially the focus lens, which is closest to the cutting area). At >100W of power heating and breaking your lens or the housing can be an issue.


#8

Does this mean we also won’t be able to truly engrave even in things like brass, copper, or aluminum? I thought they were saying steel was right out, but those softer metals might allow for some material removal with the laser.


#9

Not possible. You can remove surface treatments like anodizing or paint but you can’t engrave. An unfortunate bit of misleading marketing.


#10

But what about the videos showing macbook pro’s being engraved? Is that really a different technique?


#11

No, but MacBooks are anodized aluminum - you’re basically ablating away the microns-thick layer of aluminum oxide on the surface of the metal.


#12

I am also very interested in seeing a molyD vs. cermark side-by-side marking comparison.
@fablab_elpaso you seem to have access to lasers and have been pretty vocal in these forums. Your thoughts? Or better yet, photos from actual tests that you may have done?