What material will do this?

[Brian Lamb]

I have a customer asking for instrument panels. They need to be black, engraved with white letters, then be able to be backlit for night time operation. So do they make a clear substrate with a white layer below a black layer? I have found all the two layer material, black on top, white once engraved, just not sure where/what to look for as an all in one material. Oh... it's supposed to be finished thickness of approximately 3/16".

[andy bessette]

Tell him to call Bass Products.

[Brian Lamb]

Seriously? I ask about where to get the correct material and be able to do what my customer wants and you tell me to send him to another fabricator?

[Tony Lenkic]

Brian,

Gravograph has such a product for rotary engraving. I don't know if they have added laser sheet stock of same product.
Product is called Gravoply 1 translucent Part # 17295

Try to get a sample piece from local supplier.

I have used it for signaling panels in buildings where back lighting would illuminate engraved names.

[John Lifer]

Could you use​ a reverse engravable that is clear matte and black on back? Gemini L000-106 is one. Light would only come thru when black was engraved.

[Ross Moshinsky]

"Paint" some translucent white acrylic. You're just going to have to figure out what kind of "paint" fits the bill. You may even be able to get away with using regular old cast acrylic.

[Brian Lamb]

Tony, thanks, I'll look into that, they show it on the website for mechanical engraving, but maybe they have a laser version by now too.

John, the white needs to show well backlit or not, so not sure that will work.

Ross, that's probably the route we will take, he has already experimented with automotive paint on the clear substrate and then mechanically engraved. Just have to find out if the laser will cut the black paint and not leave any residue.

I was hoping I could use something called Laserlights (in my old Laserbits catalog) which is only .004" thick and laminate it to a sheet of clear, it comes with adhesive backing. Then laser the engraving and hopefully at just a couple thou thick it would be thin enough to light up when backlit. I haven't done much plastic engraving, mostly anodized aluminum, cermark and wood, so this is a new adventure....

[Joe Pelonio]

I did this for a car dash one time, and it seemed to work. I sprayed the clear cast acrylic with 2 coats of black, engraved the lettering and other graphics in reverse through the paint, then sprayed a light coat of white. I used Krylon for plastic.
He used bright LEDs under it and said it worked, but I never saw it at night after he installed it. I was careful to engrave just through the paint and not deeply into the acrylic.

[Kev Williams]

this thread kicked on the ol' wayback machine--

This is some of New Hermes translucent black/white--
tran1.jpgtran2.jpg

This sign is the very first thing I ever engraved with my brand new Concept 2000 when we got it- back in 1981! To engrave that sign the day before would've taken 2 or 3 hours, and no automatic line compression with a pantograph! The Concept took about 20 minutes from layout to done. It's been in that place on the wall for at least 25 years!
I pulled it down just to take a pic of the back of it-- The funny part? It's the only thing I've ever made with translucent- (never had a call for it)

And even now, it still doesn't come in laserable form, at least not from NH/Gravograph... And, as you see in the pics, the white is readable but it isn't all that white, it pretty much needs to always be backlit-

Painting will work, it should engrave fine, just be sure to wet sand the plex with 400 so the paint will hang on good. My only concern would be the durability of the paint, resistance to scratches, etc.. using catalyzed auto paint should fix that issue, but I've never engraved thru good car paint so a test would be in order...

[Bert Kemp]

I find a good epoxy appliance paint to work well. Its very tough

[Michael Hunter]

I'd do that job with black/white Rowmark Laserlights material stuck onto clear acrylic.

The white layer in the Laserlights is so thin that the light will shine through easily.

[Brian Lamb]

Thanks for the confirmation of that, it was my first thought. I'll have to do some test pieces and see how well it works.

[John Lifer]

Ok, engraved black top surface, white is behind, adhering with the preapplied adhesive to clear acrylic. Will light go through the adhesive layer ok? Or should you use plain sheet and strategically glue? Just wondering.

[Brian Lamb]

I don't know for sure, but most thin adhesive layers I have seen are clear-ish, so I doubt the adhesive will be an issue. I use a UHMW that is self adhesive and it's completely clear, the adhesive that is, the plastic is whitish/translucent.

I need some other items from Johnson Plastic next week anyway, so I'll order some to test with.

[Brian Lamb]

It's been a while, had some power issues with my laser tube and it's out for a re-charge, but I got a loaner tube and ran a test on this instrument panel idea. I used some of the Laserlights black with white underneath and stuck that to some clear acrylic. Ran a little test today and pretty good results. Customer won't use it because he needs all edges covered so no light leaks from any of the edges. But if you had the need to make an instrument panel that could be backlit, this would work well.

This is back lit with a LED light

IMG_1870.jpg

This is in daylight, square at the top was my power grid test.

IMG_1872.jpg