Thanks @evansd2 those are great ideas! I never would have thought about the flooring product.
The Cohas link is almost perfect, just too big. I wonder if it is possible to reliably break those in half? I’ll have to get some and try, I am sure I can use those stones for something else if they don’t break well.
Got a dremel? A score and snap might work pretty well.
Or break it off rough, and then go to town roughing up the edges all around, and go for a more rustic look overall?
One thing that I might be worried about with flooring… they may seal it, and that might not be good for your fish. I might consider staying away from flooring for that reason now that I think about your application.
I was thinking about clamping the big piece in a vice and tapping it with a hammer to try and break at the pinch point. If the edge is rough, that is OK because it would be the edge concealed under the gravel. And if that doesn’t work, adding a scoring step might do it.
Good point about chemicals, but the flooring product would still be useful for dry land artsy applications.
I have some of uniform gray color and some travertine from a big box store. They came attached to a plastic mesh. For both, I found that putting them in a tub (sink) full of very hot water (heated in a kettle but, not quite boiling – I wore heavy rubber gloves while doing this) melted the glue holding them to the mesh. They lifted right off and I was able to wipe the glue residue right off with a paper towel.
Very nice. I have been experimenting with reclaimed slate shingles. I have obtained deep engravings, but not the contrast that you obtained with your settings. I tried your setting and get the good contrast, but with little depth of engraving. I was using too much power to get the high contrast markings.
This particular piece was very flat and uniform. On other pieces I try to enter an average height and if it varies by +/- .1" it doesn’t seem to matter much.
The quality of the mark you get is wildly variable, it just depends on the material. The slate-like rock in this item turned out to be perfect, making a very bright mark with no need to remove any material.
I then ordered some slate chips off Etsy and they are worthless, the marks are too low-contrast to be useful.
I have some slate roofing shingles. Your settings have given the best contrast, but still not as good as your first image. Waxing the surface before engraving does give better contrast as it makes the slate darker. However, that may not work well in an aquarium.