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View Full Version : Brick engraving turning to black glass?



Emma austin
07-21-2011, 1:40 AM
I imagine you have to have a very powerful machine to do this?
I have engraved a few clay bricks with a mask, 100 power 4 speed, engraves well, then spray paint black. Looks good :). But noticed on a brick engraving website, that they were promoting their bricks as being lasered and turning to black glass, which means they will not fade etc.
Would they be using a heap of power to do this?
Thanks

Bruce Dorworth
07-21-2011, 3:21 AM
I don't think any amount of laser will turn clay to glass. I think only the Good Lord can do this, and he won't use a laser. He might use a lighting bolt :<)

Bruce

Michael Hunter
07-21-2011, 4:09 AM
My method for vitrification is as follows :

Put tile (or brick) 10mm (3/8") BELOW the focus point.
Vector at full power and very low speed (3 or 4% on my machine).

This way, I get nice even lines of glass about 1.5mm (1/16") wide.


I did try rastering too, but the small and erratic amount of vitrification formed tended to be cracked off by the next pass of the laser, giving very poor results.
Rastering at a faster speed can engrave some bricks and tiles, though without vitrification.

Emma austin
07-21-2011, 4:45 AM
Thanks Michael. So you only would be able to do words that way wouldn't you? I wonder who they do logos etc, as surely you couldn't vector those.
I like the finish of my rastering and then sprayed black. But am interested in the black glass look.. will try it right now!

Michael Hunter
07-21-2011, 6:19 AM
Doing other people's logos would have its problems. No reason why you can't be a bit adventurous though....

202514

Emma austin
07-21-2011, 6:49 AM
Well I tried, obviously don't have enough power as couldn't get it to go black. Got it looking like clear glass though.
Guess I will stick to engraving and colourfill :)

Dan Hintz
07-21-2011, 7:38 AM
Emma,

You shouldn't have any problem vitrifying the brick with 50W, just go slow (the 1-5S range should be about right for you). Are you sure you have clay bricks?

Tristan Ranatza
07-21-2011, 4:21 PM
I have a 75 watt and I can get the nice glassy beads easily. I turn up the power to 100 and the PPS to 5000, do it slow I guess around 15-20 vector only. If you want to do logos you can do a "vector fill" in Corel (forgot how to do this honestly, though I do know where the menu is). Donít cross any line or you will get cracking!

On glazed tile it (at least white tile) it turns the bead slightly blue and it cracks easily if you use too much power.

Greg Bednar
07-21-2011, 4:37 PM
<snip> If you want to do logos you can do a "vector fill" in Corel (forgot how to do this honestly, though I do know where the menu is). <snip>

I'm vaguely familiar with a "mesh fill" is that what you're talking about. But it's use, as of this writing, is beyond my ken regarding laser engraving.

Dan, are you up on this?

Dan Hintz
07-22-2011, 6:30 AM
Sorry, Greg, I'm no Corel master by any means. But I'm willing to bet a Google search on mesh fill will net you a bunch of tutorials.

Mike Null
07-22-2011, 7:25 AM
I don't believe mesh fill would be relevant here. It is a rarely used tool for engraving and more applicable to graphics use.

Nonetheless, it's an interesting tool. (if I ever had any spare time I might experiment with 3d drawings and test this tool)

Scott Shepherd
07-22-2011, 8:20 AM
You're not looking for mesh fill, you're looking for the contour tool and use the "To Center" option on it for all objects to be engraved.

You need to vector a clay brick, not raster it.

Tristan Ranatza
07-22-2011, 5:22 PM
You're not looking for mesh fill, you're looking for the contour tool and use the "To Center" option on it for all objects to be engraved.

You need to vector a clay brick, not raster it.

This is exactly what I was referring to. Don't have the chance to use it much but when you need it it works like a charm!

Wish they would make a "spiral" tool that did the same thing as the contour tool but spiraling into the center. It would make brick and tile work that much quicker!

Scott Challoner
07-22-2011, 5:31 PM
This is exactly what I was referring to. Don't have the chance to use it much but when you need it it works like a charm!

Wish they would make a "spiral" tool that did the same thing as the contour tool but spiraling into the center. It would make brick and tile work that much quicker!

There is a spriral tool. You can place the spriral inside and object and do a trim. Probably not exactly what you were looking for but it may be close enough.

paul mott
07-23-2011, 5:07 AM
The wavelength of the laser being used has a lot do do with the surface effect that can be produced on clay bricks. The CO2 lasers at 10600nm are no where near as effective as the YAG lasers at 1064nm.

Paul.

Mike Christen
07-23-2011, 11:03 AM
A good way to do vector fills is using the blend tool. Need to give this clay a try.

Greg Bednar
07-23-2011, 11:14 AM
If this link is inappropriate - please remove - but here is the place to find out the how to. : http://www.hltlasers.com/reference/Brick%20application.pdf