[aocarving]

I sandblast bricks for fundraisers and would like to move up to the 21st century. What is the best laser marking material to use on bricks and limestone? Cermark, Thermark, LMM or (???) ? Will a 40 watt CO2 laser work out OK, on brick?

[zax15uk]

I would stay in the dark ages with this project.

Use a plotter to cut the sandblast mask and have at it with the abrasive.

The results will be much better than a small laser could achieve, both in contrast and longevity.

Zax.

[aocarving]

Zax, Thanks for the input. Would a larger laser work better, like a 60 watt. Have you used a laser on bricks or stone? I have seen where others etched bricks with a laser, but I haven't found out what they use. Any info would help. Thanks, AO

[Litografa]

Bad contrast, but reasonable good engraving depth. So you can fill engraved areas with more contrast paints.

[aocarving]

Litografa, Thanks for the post. I could not tell much in your picture, I am buying a new monitor soon. My original question was, will Cermark, Thermark, or any other similar laser marking material, bond to bricks with a 40 or 60 watt laser. Have you had any experience with bricks or stone? I have seen laser etched bricks and they look fantastic! I just need to know what it takes to do it myself. Thanks. I appreciate any input you can offer. AO

[Litografa]

There is two types of red bricks here in Lithuania - porous and glossy.
Porous looks not good, but engrave well in depth. With 30 Wt laser two pass at 100% power/30% speed you can reach up to 1 mm in depth. Later usually my customers fill engraved areas with paints as engraving is grey/brown color.

Glossy bricks have something like glossy glass covering on top. Direct engraving is very difficult and you can change only color of brick from red to light grey.

We have some products for engraving on glass/ceramics
LITOSCRIPT spray’s for metal, ceramics and glass | LITOGRAFA : GLOBAL VIEW - LOCAL TOUCH
Black spray work good on bricks, but sometimes there is areas on brick, which have (I think) something wrong with coating. In this areas image became not black, but grey/light grey.

Now we are working on special spray which will allowed engraving on stone with laser. Possible colors - black, white, gold, silver. We already have first results and I expect products ready for sale will be available in June 2011.

[zax15uk]

Zax, Thanks for the input. Would a larger laser work better, like a 60 watt. Have you used a laser on bricks or stone? I have seen where others etched bricks with a laser, but I haven't found out what they use. Any info would help. Thanks, AO

I have done a fair bit of work with polished stone and the results are excellent, but bricks (at least the ones I have tried) do not work well.

I have not tried Cermark due to it's cost.

Zax.

[aocarving]

Litografa,
Thanks, so much, for the info. This is what I was trying to get an idea about. So if I used a 60 watt laser, I could probably go a little bit deeper then use a marking material (Such as yours or another brand) to fuse it to the brick, as the last stage, correct? I engrave bricks for fund-raisers (among other things)and what most people want is to be able to read it and for the spelling to be correct. It doesn't have to be picture perfect. I know when to be precise because I also carve portraits in granite, glass, ceramic etc., life-size on down to the size of your thumb, as pendants. If this sounds like I'm on the right track, or wrong track, please let me know? Thanks, AO

[aocarving]

Zax,
Thanks for the reply. I just posted a reply to Litografa, that may shed some light on the problem I'm trying to solve. Any feedback would be appreciated.
Thanks, AO

[Litografa]

My advice to you do not use any special chemistry, but engrave MAY BE multipass to reach engraving depth which will be enough for paint filling. After engraving fill engraved areas with contrast paints and everything will be fine

[aocarving]

Litografa,
Thanks again. Not sure what you mean by "special chemistry" ? Engrave the brick to depth (with multiple passes, if needed), then fill with paint, then set paint with the final pass with the laser, correct ? Thanks, AO

[Litografa]

Special chemistry = Termark, Cermark, Litoscript

Process = Multipass engraving, filling with paints, MAY BE cover with UV protection (car laque)

[aocarving]

Litografa,
When I sandblast a brick, I leave the stencil on the brick. I then spray paint it, let it dry, then peel the stencil off. I then check to see if the paint seeped under the stencil and then touch it up if need be. Question: If you're talking about using "regular" paint, how do you fill in the lettering without making a mess ? Hand paint the letters??? I can see using the special "paint" and curing it with the laser, then washing the excess off that was not hit with the laser. Do you have a trick to paint the brick? Just trying to get all my ducks in a row. (That's an old Lithuanian saying, you know!) HA! (;>) AO

[Litografa]

Practically the same as you do, but there is a lot of acrylic paints, which work well on acrylic filling. You just engrave without mask, fill engraved areas with paints using brush and removed not necessary paint with towel.

[aocarving]

Thanks for all the help. Now it's time to run a few tests. I'll let you know how it goes. AO

[LaserHead]

You don't need cermark or anything else. You need a clay brick. If you use a clay brick, the image will be black and fused into the material. There's a trick to doing it all. It's a bit lengthy to type or hard to explain. But it HAS to be a clay brick. If it's a concrete brick or stone, it won't work.

But clay will turn nice and black with your wattage.

If you have clay bricks, then PM me and I'll see if I can find my documentation on how to do it, in detail. I got the tip from a applications seminar I attended a year or two ago. I saw the results and the method and it was easy and the results were fantastic. Only issue I have is I can't find clay bricks at the big stores.

[bpoulin]

Couldn't you put a masking layer over the brick, then laser through it, then paint, and remove the mask? It might take multiple passes but should work.

[aocarving]

LaserHead,
Glad to hear about the clay bricks. That is what I usually work with. If you need clay bricks, a building material or brick dealer is where you'll need to go. (Yellow Pages in your area)

[aocarving]

bpoulin,
Thanks for the input. That thought hit me after I talked to Litografa the other day. I found a man with a 40 watt laser that is going to try that with (Tan) masking tape and silver Ductape (Duck tape) If either/both work and it will burn into the brick slightly (just enough to keep foot traffic from being in contact with the paint), then I will be able to use a laser on both types of brick. Thanks again, AO

[bpoulin]

My first thought was high tack vinyl, like for sign making. You can buy that stuff by a huge roll. Vector cut it at low power peel it back, then raster the image into the stone, spray, de-mask, and voila!! Also try blue painters tape. I'm not sure if it'll have enough tack to stick to the porous brick? Let me know the results with masking and duct tape.