I want to make some slate coasters as a gift for one of the hubs fellow Navy Chiefs. They are fond of things with the gold chief anchor. I was wondering if it is a good idea if after I engrave the slate paint the etching with gold. I see most people leave the slate natural with oil but I wanted to keep the anchor traditional gold. Thoughts?
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I don’t know how you plan to go about “etching with gold” but I can tell you that engraving slate does not result in tangible amounts of material removal.
You could engrave the design and use it as a guide to apply the gold.
I should have been more clear. I wanted to know if I put masking on the slate could I then paint the etching with gold paint and have it last.
Well first of all the lasered slate is going to last just fine on it’s own - it can be scratched at, but so can any other finish. That said, if you are going to paint it I do think engraving it first is the way to go - I have not tested this but it seems to me that the engraved surface would be much more accepting of paint than the unmarked one.
If it were me and the design needed gold I would:
Mask the slate
Engrave the design
Paint over the design with gold, multiple coats as needed
Seal with brush-applied gloss varnish
Remove mask
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I think the painting over masking is a good idea in principle, but may not work out so well. With some masking materials and paint there seems to be a capillary action that draws the paint under the masking. This weekend I tried sealing an engrave with 2 coats of a spray on polyurethane before spray painting and while it helped, it didn’t 100% fix the problem. Considering how uneven slate will be I question if you can get a good seal between the mask and the slate. Hand painting with a fine brush (as opposed to spray paint or a roller or similar) while the masking is still on may be your best bet without a lot of experimenting.
in regards to how well it will last? IDK.
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Thanks! I may opt to not do the gold as I have had trouble with masking and paint seeping out. But I just looked at the coasters I’m using and happen to have one that is broken so i think a test is in order!
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Let us know how it goes!
I have found this to be more of a problem with spraypaint than hobby acrylic via brush. I think with brushed paint you’re able to use less paint in a coat, which helps prevent seep.
My tests have been on Chemcast acrylic though, not slate. I expect slate isn’t going to be as smooth as plastic which will exacerbate seep issues.
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If you can get a reasonable seal on your mask edges, you could try a thicker medium like Rub N Buff or gilding wax. If you can’t get your edges down, though, a small paintbrush is going to be your best bet. Good luck!
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If it has to be slate, can’t help, but if you’re open to other options, you might try ceramic tiles. I had pretty good results with black tiles. Engraved, then used gold rub-n-buf. The engraved areas caught and held the color, while the ceramic made it easy to clean off.
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How about applying some gold leaf to the masked tile. I don’t expect that would bleed under the masking. 
After removing the masking I would apply a sealer designed for slate on the entire piece.
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And remember you can flip it over and do another test on the bottom if the first doesn’t work out as you want 
All of my fails become donor coasters for backside testing.
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I bought some Liquamask just for this scenario, thinking that it would do a better job than paper masking or tape at preventing seepage on the rough surface of slate. Unfortunately, I have not had the chance to test it yet. I will try to run a test with it this weekend.
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On a textured surface like slate I think jbpa’s idea would give the most reliable results.
You can also sand the entire engraving off. It takes surprisingly little effort. I found that 400 grit sandpaper made a surface that was indistinguishable from the original, just flatter.
I don’t know when or how this was done, it might be 25 years old as it was in stuff from my mother who died in y2k but it is in slate and it is deep.
You can get"gold" powder (actually anodized aluminum) that could be rubbed into the engrave surface that is faked “gold leaf” and resembles it.
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Thanks for all the suggestions! I am currently moving my work space so I won’t be trying anything out until this weekend. I’m excited.
Aliens made it
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Perhaps a Firebird with lasers in its eyes, but probably from the Seattle area.
A very early selfie?
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