PDA

View Full Version : What material will do this?



Brian Lamb
06-16-2017, 5:43 PM
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
06-16-2017, 6:53 PM
Tell him to call Bass Products.

Brian Lamb
06-16-2017, 7:06 PM
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
06-16-2017, 8:27 PM
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
06-16-2017, 9:40 PM
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
06-16-2017, 10:15 PM
"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
06-16-2017, 10:45 PM
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
06-16-2017, 11:51 PM
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
06-17-2017, 12:17 AM
this thread kicked on the ol' wayback machine--

This is some of New Hermes translucent black/white--
362243362244

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
06-17-2017, 9:02 AM
I find a good epoxy appliance paint to work well. Its very tough

Michael Hunter
06-18-2017, 5:38 AM
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
06-18-2017, 10:25 AM
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
06-18-2017, 10:54 AM
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
06-18-2017, 11:22 AM
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
08-03-2017, 10:51 PM
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

365274

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

365275

John Lifer
08-04-2017, 12:28 PM
Make it three piece.....
Use solid black acrylic say 1/16" thick and make open rectangle border around the laserlights. Adhere to the clear acrylic. I would think that would keep light from shining around the laserlight/acrylic intersection. (If I understand your problem)

Brian Lamb
08-04-2017, 1:46 PM
I think I follow... a border of black acrylic around the clear, then stick the laser lights on top of it all. That would work except for they want drilled and countersunk holes in the face for mounting, that's the real issue, you would end up with a light ring around each screw hole.

The current brainstorm from them is to use clear and paint with a layer of what and then black on top of that. Then I'm supposed to laser of the black leaving the white behind... not sure how reliable or durable that will be... but hey, I'm only responsible for the laser work.

John Lifer
08-04-2017, 5:02 PM
Actually somewhat inset the laserlights. Use 1/16 black and laserlights is what .020 or so? use o-rings around the screws....
I doubt you are going to laser only thru one layer of paint consistently. And it sure won't be durable.

I know they want white, but get a sample of a Colorhues EHX in Black/Pacific. Light blue or a Yellow (lemon zest or citron) Yeah, that's their color names.....
Shame there isn't a pure white, but the blue is pretty light color and might work.

Jerome Stanek
08-05-2017, 4:33 PM
have you tried engraving as a mirror image so the black is on the bottom

Brian Lamb
08-22-2017, 10:07 PM
Dredging this thread back up. Laserlights works great, but customer wouldn't use it because of numerous holes and such through the part that would allow for light leaks. by the way, it's .004" thick, a .002" black layer with a .002" white layer underneath.

So, the customer has decided to attempt several coats of white paint under several coats of black. I have successfully gotten a useable result, but I'm seeing a bit of "banding" that I would like to eliminate if possible. Given that the black paint is thin, and the white paint is thin, I can't just blast with more power and get a cleaner engrave, that would take me through to the clear plastic and eliminate the white colored text.

I tried going out of focus in .050" increments to enlarge my spot size and see if I could get smoother results... which worked to a point, .100" higher than usual seemed to be the best. Any suggestions to get rid of the raster lines in the text?

This is a sample piece backlit with a flashlight so you can see the issues.

366603
SaveSave

Kev Williams
08-24-2017, 8:38 PM
Universal laser? Going from memory here -- You should have a halftone section in your print driver, on mine there was like one button to click that would then reset slider bars for brightness, contrast, etc. based on the graphic-- it always worked near perfect for me- If your does this, paint your lettering 70% black and let the driver choose halftone settings. The engraving will automatically dither, and may take care of the banding--

John Lifer
08-24-2017, 8:45 PM
Brian if you are trying to just cut thru black and not the white basecoat, why paint white to begin with? Just cut well thru black paint and then colorfill white?

Brian Lamb
08-24-2017, 9:08 PM
Kev, I will give that a try and see what happens.

John, the customer wants white for daylight visibility and then still thin enough to backlight it with led's to have nighttime visibility. It's an instrument panel component for an airplane.