multi color mirror advice needed

[Chad Fitzgerald]

Ive done several mirrors with just one color(black) painted on the back, I have a customer now that wants a mirror engraved with 3 colors, red, blue, black.Ive got a process in my head to do it but thought i would ask here to see if there is a better way to do it then what im thinking.
There is a square RED border with a wide diagonal stripe also red, and one area of red text. Centered over that will be a blue prize ribbon with blue text withing in. Then there are two areas of text, BLACK, that does not touch the other colors.
My thoughts:
Using home position,
Engrave the RED, remove and paint red(i use spray paint), once dry,
Engrave the BLUE, remove and paint blue, once dry,
engrave the BLACK, remove and paint.

Does this make sense or is there a better way. Im assuming i can rely on the home position to to start same place each time knowing that the machine will be turned off due to drying time.
Also one thing i am unsure of, the RED diagonal stripe, once painted, will i be able to engrave clean where the BLUE ribbon sits over it?

Any thoughts or advice is appreciated.
Thanks Chad

[Joe Hillmann]

I think you may end up having problems where you are engraving through the paint and mirror backing. Whenever I have done multicolor mirrors I design the artwork so none of the colors touch each other. That way I engrave the entire mirror then mask and paint one color at a time. Is it possible to change your artwork to allow you to do that? If not do a test piece and find out what happens.

[Glen Monaghan]

You're going to have to run a test to see if you can re-register accurately enough.

Sounds like you could speed up things a bit by engraving both red and black areas at same time, covering red area while painting black (to avoid overspraying black onto red area) and then uncovering and painting the red area.

Do the red and blue have to meet exactly, or could you leave a thin outline of unengraved mirror border between? That would allow for a little registration error and might also allow you to do all the engraving at once and then mask both blue and red, paint black, remove blue mask and paint blue, remove red mask and paint red without long delays.

[Chad Fitzgerald]

Both of you bring up the same point, redesign so the colors have a little separation. Make total sense, and yes i can with a little work. masking the ribbon i think will be the toughest (due to the "ruffles") but it wont be terrible.
The registering each time was my biggest concern.
thanks both of you. appreciate it.
Chad

[Chuck Stone]

The registering each time was my biggest concern.

I do a lot of things that need two or three passes and re-registration.
I use card stock or tape on the laser bed. I measure VERY carefully
an create an outline in Corel. I tape down the card stock, making
sure to position it into the top left corner and then burn the outline
just enough to see it. That helps me place the item accurately.
If I'm doing something with a good bottom edge (like thin sheet metal)
I'll use tape on the laser bed and burn the outline to cut the tape. Then
I remove the inside portions, leaving just a 'frame' of tape that makes it
easy to "seat" the part exactly where I want it.
I use the Post-It tape, but only because I got a batch really cheap.
But I like it..

[Michael Hunter]

Also one thing i am unsure of, the RED diagonal stripe, once painted, will i be able to engrave clean where the BLUE ribbon sits over it?

Obviously you need to try it for yourself to be sure, but I think that you will be OK on this.

I have done multiple layers of paint on plate glass and on each lasering operation, all the paint has been removed - even in the areas that had been lasered before.

[Rodne Gold]

We do a lot of stuff like that , multiple colour paint fills
All we do is make sure each colour has a dam , IE one colour has a thin bridge separating it from the other , we then laser it ALL in one go , without masks and just use brushes or syringes to flood fill the relevant areas making sure the paint doesn't spill over the dam "wall" , looks messy from the back , but it's never seen on a mirror. We do occasionally mask with masking tape when things get very fiddly and complex/fine
We do the same when we front etch or engrave metals/.acrylic/whatever that need colour filling , create "dams" and just fill with duco paints

[Chad Fitzgerald]

From all the advice above, i think im going to engrave all at once. I touched up the design to have separation/dam where colors meet. i never thought of brushing the paint on, that would actually work best in one area in particular where there is fine detail with colors overlapping. would be easier than trying to mask that area. will acrylic/craft paint work ok for this? The rest of it i can easily mask and spray, BUT, if i brush one area and spray the rest, will there be a noticable difference? I will try a piece doing both and see how it looks.
Thanks Again

[Michael Hunter]

I use Rustins' "Small Job" oil-based gloss paint for glass and mirrors.
The pigment is ground very fine so it gets into the frosted engraved areas well and gives a good colour.
(Ordinary household gloss has a sort of cloudiness because it doesn't get into the little cracks in the glass).

If you can't find Rustins or JapLac, then the paints for plastic models would work just as well.

[Joe Hillmann]

Rodne,
A stupid question but, Do you thin the paints way down first with that method?

[Rodne Gold]

No , we use the paints undiluted , some solvents cause stress cracking where the acrylic is engraved.