Hi all,
any pros out there engraving polished stones? I’m engraving polished agate and my vision was that it would leave the color of unpolished stone… instead it is white?? I was hoping for the image to be subtle. I’m a total laser newbie, so any feedback is appreciated if this is possible.
I haven’t tried this, but I suspect if you treat the engraved part with a clear liquid finish (like fingernail polish or varnish), it will become much more subtle. If you don’t want to get the clear finish on the rest of the stone, try masking the whole stone (painters tape works fine for this) before doing the engraving, then treat with clear finish before pulling off the masking.
thank you. i did try masking film and it did the same thing… white. are you saying treat the white with clear finish and it should ‘remove’ (lack of better terms) the white color?
I tried the clear polish… while it did dull it it still is not the natural unpolished look I’m hoping for. but, in the event this look isn’t possible with a laser and stone, THANK YOU…its WAY better than it was
I’m not an expert on the stone stuff by any means, so I’ll just throw ideas out. The stone is being bleached for the most part with very little surface removal. I have no idea how much color you’ll be able to retain, but I would start testing from the “bottom up” - using very low power and progressively testing higher and higher. You may be able to get a certain level of transparency that you’re looking for - somewhere between the base color of the stone and the opaqueness of a full-on engrave.
If that doesn’t work, maybe cutting stencils and sandblasting.
Thanks @jbmanning5 I did try as low as 20 power and it looked same as 50. I don’t have the means of sandblasting (I only have the GF for my projects), but it exactly what I need, or the look I want. Hopefully I can find a means to remove this ‘bleach’ that does a little better than the clear polish. thank you.
Then go lower. Give it a try at 1, 2, 3, 4, 5, etc power. See if somewhere you can find a line. Maybe no line exists and it either bleaches or doesn’t, but you still have a lot of room to test.
ok, I will try 10 power. thanks
And another thing you can try is setting the focus height above the actual material height. Like if your material thickness is .2 try setting the focus height at .3 or so. Note that this will also widen the engraving path so be sure to test on a scrap first.
great idea. thank you
Another possibility, although probably not good, is to use some kind of (possibly matte) finish that has a little bit of color in it to get back toward what you want. You might also be able to scrub off some of the bleached part, since it tends to be powdery.
Thanks. I did try to stub off bleach but it is very inconsistent what comes off (not much) but, I did think about a matte color close to the stone. I will definitely try. All will be trial and error. Thanks for the response!
When you scratch a hard glass like surface, you get a white scratch.
I would assume that this is because you get microscopic flaking of the surface, and each tiny surface will reflect light in a different direction. This is ‘scattering’, and unless you restore the surface in some way, for example by filling the individual flaked pits, it will always have this appearance.
yes, I’m learning 
I did find using alcohol based markers does the trick!
Great.
I expect the marker gives you back the colour by making the surface non-reflective as it dries.