Engraving rock

[Dave Kurt]

First post here - been lurking for months picking up good tips. Thank you for some great info.

A potential customer has asked for "flat" rocks engraved with quotes to be given to children. I am assuming by rock, he is looking for something like the JDS "Solid as a Rock" awards, however these are gypsum with engraveable plates. Just in case he wants the engraving directly on the item instead of on a plate that is applied to the item, does anyone have other vendor suggestions and/or application methods?

We are running an Epilog Mini24 (45watts).

Thanks in advance.

Just found this link (http://www.peternity.com/ecom/index.php?tplaction=fulldetails&productid=17&id=1) but could not determine the depth as the photo appears to have been taken straight on. Any opinions on this type of rock?

[Jack Harper]

Laserbits offers laserable stones in three sizes.

[Eric Barker]

Dave, I've done smooth dark river rocks. I first sealed them with clear acrylic, which makes them really dark, and the engraved area turned a light grey. The price was right. ;)

[Mike Null]

We have some landscape suppliers of stone, tile and rocks. I bought some very nice river rocks for sand blasting. They tend to be somewhat flat and otherwise oval and smooth. Very cheap. pick out what you want and load'em yourself.

[Dave Kurt]

I appreciate the prompt responses. Since this is our first venture into 'rocks' could you veterans offer more detailed vendor information (Web sites, phone numbers, etc...)? My Google search revealed more landscaping results than laser engraving supplies.

[Mike Null]

I would urge you to look locally as shipping can be prohibitive.

Where are you located?

[Bill Cunningham]

It takes a slow burn with a lot of power, or multiple-multiple passes to engrave a 'real' river rock.. The dark coloured "river rock" you get at dollarstores, wallyworld, and petshops is really only tumble polished marble chips which work great providing you can find them large enough and the customer is not expecting 'deep' engraving.. Sand blasting is the best way to do "real river rock", the cut is deeper and it's faster than the laser.. I did find a piece of rock (picked it up on stroll through the bush) I have no idea what it is, but I wish I could find a thousand small pieces.. When lasered, the area turned to black glass.. and it looks great..

Below are two pictures the first is laser engraved 'real' river rock... Slow to do, the second is the rock that turned to black glass, Any Geologists in the house?
http://www.sawmillcreek.org/attachment.php?attachmentid=52952&stc=1&d=1166564814

[Christian Kaplan]

I do 900 Stone for a festival. I took little simple stones in grey and engrave 9 different logos on it. every logo 100x. It was a good job. I sold each for 1€.

Nice money !




Greets from Germany

[Dave Kurt]

What is "900 Stone" and do you have any pictures?


I do 900 Stone for a festival. I took little simple stones in grey and engrave 9 different logos on it. every logo 100x. It was a good job. I sold each for 1€.

Nice money !




Greets from Germany

[Joe Pelonio]

Below are two pictures the first is laser engraved 'real' river rock... Slow to do, the second is the rock that turned to black glass, Any Geologists in the house?


Igneous rock turns to obsidian, a glass-like stone, as the result of cooling quickly when felsic lava from a volcano hits water in a lake or stream.

Perhaps the heat of the laser followed by quick cooling as the beam moves on has a similar effect?

(I recently helped my daughter with her college geology class)

[Belinda Barfield]

It takes a slow burn with a lot of power, or multiple-multiple passes to engrave a 'real' river rock.. The dark coloured "river rock" you get at dollarstores, wallyworld, and petshops is really only tumble polished marble chips which work great providing you can find them large enough and the customer is not expecting 'deep' engraving.. Sand blasting is the best way to do "real river rock", the cut is deeper and it's faster than the laser.. I did find a piece of rock (picked it up on stroll through the bush) I have no idea what it is, but I wish I could find a thousand small pieces.. When lasered, the area turned to black glass.. and it looks great..

Below are two pictures the first is laser engraved 'real' river rock... Slow to do, the second is the rock that turned to black glass, Any Geologists in the house?
http://www.sawmillcreek.org/attachment.php?attachmentid=52952&stc=1&d=1166564814

Bill, the marking on the second rock look very similar to the result you get with brick. Very interesting. I am anxious for some "rock heads" to report in on this one.

[Belinda Barfield]

Dave,

Like Eric, I've marked stones sold as "River Rock". They come by the bag at Michael's crafts, or AC Moore. They are tumbled pieces of marble. I believe the price was 2.99 for about 25 rocks. The largest is 4 x 2.5, the smallest is 2.5 x 1.5. I didn't try Eric's trick about coating first. I noticed that after a while the oil from my hands darkened the engraving to the point it almost disappeared. I haven't tried color filling one of them yet. I am definitely not one of the more experienced engravers here, so hopefully someone else can offer more insight. Kids do love rocks, so the closer you can get to the real thing may be better than using some type of composite. Is your customer willing to pay the price for really nice products made specifically for engraving, or is he looking for something more cost effective? If he is going to give them away to children I'm guessing more cost effective.

[Bruce Volden]

Perhaps a little OT but I have bought polished "slabs" of agate and this lasers well. Also they have been small enough to scan and trace and inlay into boxes creating a stunning effect! I have lotsa fun doing this....now if I could just sell some instead of my wife giving them away for graduations, weddings, birthdays, ........yawn :D :D

Bruce

[Dave Kurt]

That customer came and went with the wind - never heard back even though I sent a thorough email response. I would still like to follow through with this 'rock' thing just in case another inquiry comes my way.

[Bill Cunningham]

Bill, the marking on the second rock look very similar to the result you get with brick. Very interesting. I anxious for some "rock heads" to report in on this one.

I've never been able to get a decent mark on a brick, either the wrong type was tried, or I don't have enuff power..

[Bryan Bellars]

I've found that Slate works very well on my 35W laser. Because of the nature of the stone you normally get at least one flat surface which just needs to be leveled on laser bed. The darker the Slate the better but this can be fixed by varnishing the stone before lasering. The end result is quite a reasonable contrast in off-white.

My local garden centre sells lumps of slate (up to 12" square-ish), slate tiles for roofing (makes great table protectors when lasered up and sticky felt feet applied to the rear), and slate chippings (used as ground cover on garden borders) which I've lasered names on to for place settings at weddings - which the guests then take home as paperweights (or whatever). You can sell this easy as the association of solid rock and marriages goes down well. Sometimes get the order to do the wine bottles and glasses too!

The power needed for slate is 50% on speed and power but sometimes needs a high speed low power second pass just to clean up.

The garden centre also supplies slabs (or "stepping stones") of other rock type. I've tried Sandstone (lasers well but no contrast) and Limestone which is greenish in colour and gives a white finish.

What sometimes works well with lasered images on stone and slate is to use a few coats of black shoe pilish over the whole area first. Buff it up nicely before you start to laser and then the polish won't come off on fingers etc. Then laser through this to give a good contrast on the natural stone below.

Give the machine a good clean after you finish though, the gritty bits get everywhere.

[Bob Tate]

I did not know any better when I first got my laser, so I grabbed a few River Rock from the yard, engraved with high power and very low speed. I did not get very deep, I did get as a lot of dust. The dust scared me, thinking it must be pretty gritty and hard on bearings and such.
Next try, I masked the engraving area with that Blue Painter Masking Tape and engraved thru it. That left a fairly rough surface. I then painted that area with Acrylic paint, then pulled the tape off. It came out beautiful. I did a few more with my day job company logo and put them out in the yard at work. They were painted with Gold paint and it has stood up thru 3 winters of lots of snow, and 3 summers out in the sun. Still looking good. The Acrylic paint really holds up well.
My boss thought it was really cool and showed the rocks off to lots of people and that got me some business with the landscaper. He had me doing rocks with his business card on them. I don't think it worked out too good for him though because I haven't heard from him for a year and a half.
It was fun though.
Bob

[Barb Macdonald]

I'm a rock-hound, my old dog was too. There are ways of figuring out what the rock for Bill might be, using density, acid and scratch (and hammer) tests etc. I have a lovely big "blob" of obsidian, way too odd-shaped to laser. It shears into the coolest pieces...
I second the opinion that polished agate slabs lasers really well, but I think you're just burning off the polishing compound. It gives a nice durable contrast. The text is white. You're burning down to the quartz, I think, which is what agates are a form of. I have a huge chunk of rose quartz, but I won't test it. It's a great garden piece:) Very hard rock, quartz...
I've lasered some black-faded-to-brown marble from RONA, it has held it's mark outside for 2 winters now. No colour fill.
The black granite from RONA doesn't seem to hold much detail, but I haven't tested it much yet.
Also, lasering & sand-blasting some types of rock, including glass of course, releases silica. I wear a respirator, just to be cautious.. Don't breathe rock dust!
Have a great day!
It's summer in Toronto!
I love winter, especially when it's over.

Barb Macdonald, B.Sc. (yes, I really did)
The CREEK RULES!!!!