Full Version: Glass lasering
From: JimK (JUSTTHE4OFUS) [#1]
26 Mar 2007
To: ALL
I do both laser and sand etching of glass. Most often I combine the two for a different look and feel. I get more for the sand work so I offer the laser as a lower cost alternative uswing the rotary attachment. The problem I am having with most glass is flaking which makes for a poor appearance.
I have a 25 W and run at 100P/34S/1000PPI and 6 ID. I have a ULS M-300.
In most cases the laser-only work is acceptable but I think it can be better and not sure if I should go up or down or what I can change. When using tape and then blasting the laser work is not an issue as long as I cut through the tape.
Any advice greatly appreciated!
Jim
From: Cody (BOBTNAILER) [#2]
26 Mar 2007
To: JimK (JUSTTHE4OFUS) [#1] 27 Mar 2007
Jim,
Most of the time when I get flaky glass, it's because I'm hitting it too hard, or too slow.
I don't do a bunch of glasses, but I do run a lot of glass blocks. Even within the same lot, we get some inconsistency with the glass reaction. Some look great, some not so great.
Cody
From: Goodvol (JIMGOOD) [#3]
26 Mar 2007
To: Cody (BOBTNAILER) [#2] 26 Mar 2007
Cody,
I would love to see some examples of your glass blocks. Can you post some? :-)
Thanks!
Jim
From: Cody (BOBTNAILER) [#4]
26 Mar 2007
To: Goodvol (JIMGOOD) [#3] 26 Mar 2007
http://eternitycreations.com/glassblocks.htm
Here's a link to our website. We have a handful of examples there.
I haven't taken the time to get my site updated like I should... :-$
From: Goodvol (JIMGOOD) [#5]
26 Mar 2007
To: Cody (BOBTNAILER) [#4] 26 Mar 2007
Thanks, Cody. Those look great. I bought some blocks for my wife to paint on and we inserted Christmas lights. I've drilled some holes for her and she goes to town! I've wanted to laser engrave on them but I haven't tried it, yet.
I engraved on some extremely thin Christmas ornaments and the result was mixed. The difference in the glass caused the finished product to vary. Is this happening with the blocks!?! I wonder if color filling may improve the look? Are you masking, using wet paper, soap and water, or just going at it? :S
Thanks for sharing!
Jim
From: Cody (BOBTNAILER) [#6]
26 Mar 2007
To: Goodvol (JIMGOOD) [#5] 26 Mar 2007
Almost always, we just put the block into the laser and go for it.
We have a 35W Epilog TT, and I run these at 35% speed & 100% power. Max speed on my machine is 80 ips.
From: Goodvol (JIMGOOD) [#7]
26 Mar 2007
To: Cody (BOBTNAILER) [#6] 27 Mar 2007
Cody, I'm inspired again. I think I'll throw my company's (day job!) logo on a block and take it to work. Subtle advertising can't hurt!
Thanks!
Jim
From: Jim (JIMHUSTON) [#8]
27 Mar 2007
To: Goodvol (JIMGOOD) [#7] 27 Mar 2007
I do a LOT of jade glass engraving. With a ULS M 360 60 Watt unit I use:
80 Power
83 Speed
330 PPI
4 ID
Hope that helps. A lot depends on what type of glass you are engraving!
Jim
From: laserman (MIKEMAC) [#9]
27 Mar 2007
To: JimK (JUSTTHE4OFUS) [#1] 27 Mar 2007
Jim,
Because all glass is not created equal. What we do is to change the graphic from a solid black to 60-70 % Grey level. This really helps with what you are experiencing.
From: JimK (JUSTTHE4OFUS) [#10]
27 Mar 2007
To: ALL
Jim and Mike,
You mention 3 variables I haven't messed with:
lowering the PPI from 1000
lowering the ID from 6 (image density)
and decreasing the intensity of the black.
Looks like I have a lot try. Soooooo many combinations, and then add on the inconsistency of glass.........
Thanks!
JimK
From: logojohn [#11]
27 Mar 2007
To: JimK (JUSTTHE4OFUS) [#1] 27 Mar 2007
If you get flaking, many times you can still save the piece with a few minutes work.
Usually that means there was too much power so there likely will be a fairly deep etch underneath. I just use the corner of a razor blade or exacto kniffe and chip away. I am left with a smooth looking but frosted layer that was under the flaking.
Hints given so far are good and a couple more.
lighter gray, not solid black lettering or graphics
use photo mode in the laser driver
slow speed and high power which varies my machine
thin film of manual dishwashing liquid without paper overlay
air assist on
From: JimK (JUSTTHE4OFUS) [#12]
27 Mar 2007
To: logojohn [#11] 27 Mar 2007
lj,
Great stuff, I think this will help immensely.
Thanks!
Jim
From: Harvey only (HARVEY-ONLY) [#13]
30 Mar 2007
To: JimK (JUSTTHE4OFUS) [#12] 30 Mar 2007
I find that the highest resolution and lpi give the best result. That said, I cannot do a picture without some flaking at some density of the image. Vary the power and the greyness of the flaking area changes.
I have also done text by blasting away and leaving a carved look with no fracturing flakes.
Glass varies spot to spot. I even had an egg cup with a line of water glass in it. (The potash never made it to that spot in the mix. Leave out the potash and it dissolves in water.)