Sealing slate

Any before and after pictures or with and without images?

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Got any pix of a mineral oil treated piece?

I wonder if I could do it after the fact? Does the slate feel oily after?

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No but the image disappears from my experience. I have a really nice black (dark gray) cheeseboard with a hidden image :smile:


You wipe them with oil before cutting? I guess I thought that would cause more burning? I don’t know, it was just something I would not think about.

You do just a thin wipe before engraving. Just put a little bit on the rag, quick swipe and done. It just barely coats the top surface making it a little darker and giving more contrast when you engrave it. If you put it on afterwards it kind of defeats the purpose and would darken your engraving as well.

**Edited to add-- It only takes a very small dab of oil. You don’t want to saturate the slate, just give a light coating. Rub it in well, then wipe off any excess. The tile should be darker, but not slick with oil. The oil will continue to absorb and won’t be greasy in a day or so.


I’m at work right now, but I’ll check to see if I have any non-oiled pieces at home to compare with.

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I will add that any food grade cutting board mixture works as well such as a beeswax / mineral oil mix. It will coat the slate but doesn’t seal and close off the surface like a synthetic lacquer or sealant would.


Stone isn’t really burned away in the same way wood and other fibrous material is. Stone particles are basically desenegrated by the laser. If you use too much power and the pulverized pieces get too hot, they will melt into little glassy globs that stick to the surface of the slate.


Learn new things all of the time. Thanks for that. I had no idea.

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That makes sense that it leaves the engrave highlighted against the now darker stone. I’m going to have to try it when I get back (on a business trip).

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OK, here’s an example. Please ignore the very low lpi crappy engrave as it was just a contrast test. @PFI-Guy



That oiling really makes a difference.


Yeah that’s huge. Next time.


I’ll be danged… It never occurred to me to pre-treat slate (or post- for that matter). Looking forward to comparing straight mineral oil to a beeswax & oil board conditioner. :sunglasses:


Yep, I oiled after and lost the image.



Oh cool, you’ll save me buying beeswax conditioner to test. I’m leaning towards beeswax being better than straight mineral oil, but I really don’t have anything scientific to to base that on other than bees are cool lol. Let us know what you find out.


Funny you should say that… i did a first purification run on some wax today!
Here is a 500gm block!


Oh man, that’s beautiful!

It is early in the season here so i am swapping over old frames (helps to manage possible diseases and infestations) which gives me a steady supply of wax.

At this time of year (early Summer in Oz) the bees are eager to make wax so they rebuild the new frames very fast


Does oiling stop the slate coaster from being somewhat absorbent?
And if so, is that more or less desirable than a coaster that does absorb condensation/spills?

Of the top of my head, I would think non-absorbent would be easier to clean, but absorbent would be more functional. (The difference in engraving contrast is not in question.)