Outdoor Life of Black Granite

[mike klein]

I have a customer who want us to engrave a plaque which will be placed outdoors along a river facing facing south into the sun every day. I've used a lot of
the black granite indoors but have yet to use it outdoors, until now. Found a couple sizes at Laser Bits that will work but my concern is will the material and engraving
hold up outdoors.

[John Lifer]

If this will show up, it is a page from the epilog facebook page. BTW, they take any laser 'enthusiast' no matter brand. As I lust for an Epilog, I guess I fit

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Is a polished black granite outdoors 11 yrs, engraved with Epilog and White Paint filled.
So, I guess you need to fill to make it last.

[Lee DeRaud]

This has been on my back (west-facing) wall since 2007...it's just the cheap Home Depot granite tiles. No paint fill.
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[Ross Moshinsky]

I have a customer who want us to engrave a plaque which will be placed outdoors along a river facing facing south into the sun every day. I've used a lot of
the black granite indoors but have yet to use it outdoors, until now. Found a couple sizes at Laser Bits that will work but my concern is will the material and engraving
hold up outdoors.

Be careful with Laser Bits. Specifically ask if it's granite or marble. I might be mistaken, but at one time there was a bit of confusion if they were selling marble or granite. Granite will last well outside, marble will not.

[Bert Kemp]

I find that marble holds up well outside, altho its not long term this piece that I goofed on has been outside in the Arizona sun for over 3 years and shows no sign of fading or any degradation at all. Looks the same as when I did it .SeaBees.jpg

[Samuel Espy]

Bert, AZ is likely not a great test regarding the degradation of marble outside as it is not UV that harms marble. Though it is a great state. Rain, or more specifically the minute amounts of acid in rain, is the culprit. Marble is comprised mostly of calcium carbonate (as is limestone), and acid rain is very reactive with calcium carbonate. Sandblasted marble outdoors of course maintains its features much longer than lasered marble because the features are often etched orders of magnitude deeper than the features etched via a laser.

[mike klein]

Thanks for all the input guys, I orderd a few sample granite pieces from Laser Bits today so well see how they work. I did have a piece of granite I picked up at
Home Depot some time ago and tried it on both the co2 and fiber, and I liked how the fibe gave me a brighter white and deeper mark than the co2. We'll see
how it works on the stuff from Laser Bits.

[Bert Kemp]

Samuel, I guess like most people you think AZ is dry and desert, where in reality AZ is mostly mountains and has weather much like New England. The Valley of the sun which is Phoenix metro area and parts south are dry, but they do get rain. Where I live I get more rain then the valley and a little further north they get rain almost weekly and snow in the winter.
My back yard https://www.youtube.com/watch?v=WWI9nCrska4

Bert, AZ is likely not a great test regarding the degradation of marble outside as it is not UV that harms marble. Though it is a great state. Rain, or more specifically the minute amounts of acid in rain, is the culprit. Marble is comprised mostly of calcium carbonate (as is limestone), and acid rain is very reactive with calcium carbonate. Sandblasted marble outdoors of course maintains its features much longer than lasered marble because the features are often etched orders of magnitude deeper than the features etched via a laser.

[Glen Monaghan]

Samuel wasn't talking about just rain, but acid rain. Industrial emissions in the rust belt of the north-east and mid-west make the rain acidic, which can be harmful to plants and, of interest here, cause certain stones such as marble to decay. With much less old-school industrial infrastructure, you'd think it wouldn't be much of a problem in Arizona but, apparently, Arizona _does_ have some issues with acid rain due to things like copper smelters and Mexican industrial emissions that propagate up into AZ.

[Bert Kemp]

I don't know how much acid rain we get, possibly not a lot then if my marble is still good after 3 years. Would be interesting to test it and see.

Samuel wasn't talking about just rain, but acid rain. Industrial emissions in the rust belt of the north-east and mid-west make the rain acidic, which can be harmful to plants and, of interest here, cause certain stones such as marble to decay. With much less old-school industrial infrastructure, you'd think it wouldn't be much of a problem in Arizona but, apparently, Arizona _does_ have some issues with acid rain due to things like copper smelters and Mexican industrial emissions that propagate up into AZ.

[Bob Davis - Sturgis SD]

Mt. Rushmore, carved from granite, erodes at the rate of 1 inch per 10,000 years. I read that years ago, lol.