First time engraving a mirror - need help

[natasha robbins]

Hey all,
This is my first time engraving on a mirror so i'm not sure what i might doing wrong.
I have a Gravograph LS 100 engraver
I have my Power @ 90% Speed @ 41% and DPI 600
I'm only getting through to the mirror just a little bit. part will be clear but the other part still has the "gold type" covering on it....am i missing a step or could it just be the type of mirror i have? I bought it at Lowes.

Thanks in advance for all your help

[Dan Hintz]

Natasha,

It will help everyone in the future if you provide machine details (including power) in your signature.

I see no reason why you would lase at anything other than 100% power if you're going slower than 100% speed. You could make two passes, or try 100P at the same speed (41%). The problem you're running into is a non-uniform coating thickness (assuming your machine is aligned properly), and there's not a lot you can do other than multiple passes or beat it into submission with more power.

The cheaper mirrors (Lowe's would be included in that most of the time) are better due to their relatively thin coating.

[Lee DeRaud]

I've got a 25W (nominal, seems to run a little hotter than that) ULS, just got done doing some tests: cheap Stanley mirror tiles from Home Depot, even cheaper mirror tiles from Ikea, and some samples of mirrored acrylic I've had laying around forever. The coating on all three seemed very uniform.

All worked fine at 100% power, 50% speed, image density set to 5 (one notch higher than default, no clue what that works out to in DPI). It's not a fast process though: about 50 minutes per 12"x12" tile, partly due to the higher-than-normal density setting.

[Dan Hintz]

Lee,

1-6 = 75, 125, 250, 333, 500, 1000 dpi (if memory serves, need to verify when I get home)

[Lee DeRaud]

Originally Posted by Dan Hintz

1-6 = 75, 125, 250, 333, 500, 1000 dpi (if memory serves, need to verify when I get home)

Thanks, I don't recall seeing that in any of the docs I got with the machine. (It's an early-'05 VL200.)

[Dan Hintz]

Originally Posted by Lee DeRaud

Thanks, I don't recall seeing that in any of the docs I got with the machine. (It's an early-'05 VL200.)

It's not in the docs I have with the machine I received earlier this year... just another notch in the ULS "poor documentation" rung.

[Bill Cunningham]

I usually buy my mirror cut to size from a local glass company that does wholesale as well. The coating on the back is a gray colour, and when etching it smells EXACTLY like gunpowder.. This is the only mirror I have used that has that very distinctive odour, and it etches flawlessly.
There's NOTHING like the smell of gunpowder in the morning

[Lee DeRaud]

Originally Posted by Bill Cunningham

I usually buy my mirror cut to size from a local glass company that does wholesale as well. The coating on the back is a gray colour, and when etching it smells EXACTLY like gunpowder.. This is the only mirror I have used that has that very distinctive odour, and it etches flawlessly.
There's NOTHING like the smell of gunpowder in the morning

Really? I'll have to go outside where the blower vents next time I do some...can't smell it at all inside.

[Bill Cunningham]

Originally Posted by Lee DeRaud

Really? I'll have to go outside where the blower vents next time I do some...can't smell it at all inside.

I probably could smell it because of the restricted airflow I was getting from the clogged grid on the blower intake. My legs get cold now when I stand in front of the machine Quite a difference.. And I LOVE the smell of burning gunpowder too..

[Duane Parcells]

Hi Natasha

The gold covering may be ok. It depends on what you are doing. For a photograph on a mirror you want to be able to see the metal plating. The parts that are stripped away to bare glass will be the showing as black or what ever color you repaint. The laser will take off all the paint and parts of the plating when your settings are right. If your putting a graphic or vector drawing on a mirror then you want all the plating stripped away.
I run photographs on the cherry setting in Photograv at 300 dpi. Higher dpi showed poorer quality in photgraphs (on mirrors). Try 100% power and adjust your speed. Every machine is different, for my 75 watt I run 100 power and 50 speed for Stanley mirrors.
The mirrors can vary in quality. Some of the cheaper ones available at Home Depot or Lowes have fine ridges in the coating on the back which prevents even burning. They are also thinner than most. I've had nothing but trouble with those. The one brand that I found consistency and quality in is sold under the Stanley tool company label. Keep at it. You can get amazing results with mirrors.
Duane

[Lee DeRaud]

Originally Posted by Duane Parcells

The mirrors can vary in quality. Some of the cheaper ones available at Home Depot or Lowes have fine ridges in the coating on the back which prevents even burning. They are also thinner than most. I've had nothing but trouble with those. The one brand that I found consistency and quality in is sold under the Stanley tool company label.

Hmmm...the cheap ones at my Home Depot are Stanley...mixed in with something called "Basics" brand, which has the exact same printing on the back of the box. No ridges, engrave fine. That's the good news: all six in the pack I bought have one bad edge, where the mirror is visibly discolored (from the front) for about the first 1/8". They're 3mm glass, which seems to be standard for the plain-edge ones.

If you have an Ikea nearby, their "Lots" mirror tiles are much better: 30cm square, with nicely polished edges. But they're not available on the website.

[Dan Hintz]

Originally Posted by Lee DeRaud

If you have an Ikea nearby, their "Lots" mirror tiles are much better: 30cm square, with nicely polished edges. But they're not available on the website.

I second that... we have an Ikea relatively close to us just north of D.C., so Amy and I take a visit there every few months to pick up engravable toys and doodads.

[Niklas Bjornestal]

Ikea also has some wall tiles called "fastbo" (at least in sweden) that engraves well... i just have to figure out a good way to cut them

[Lee DeRaud]

Originally Posted by Niklas Bjornestal

Ikea also has some wall tiles called "fastbo" (at least in sweden) that engraves well... i just have to figure out a good way to cut them

You mean these? Looks like they're just white melamine...how thick are they?

[Dan Hintz]

Originally Posted by Lee DeRaud

You mean these? Looks like they're just white melamine...how thick are they?

The package is 1/8", so if two come in it...

"High-pressure melamine laminate" and "stainless steel color"

Interesting...