Printing legend on plastic panel. (Racal 9835) - Page 1
Forum section: electronics / repair

author: Andy Watson
author_rank: Super Contributor
timestamp: June 19, 2016, 06:24:55 pm
content: Any ideas how I could re-print the legend on this Racal 9835 front panel?Most of the missing paint could be touched-up but I would like to eliminate the crack that extends from the middle of the push-button table, through the display, through the display time pot and on to the hole for the stop push-button. I could possibly glue the crack but this would certainly remove much more of the legend in the process.The panel is 0.050" thick transparent perspex/plastic. The original legend was printed on the reverse. Assuming that I can obtain the blank material, how might I go about printing the legend?

author: bitslice
author_rank: Frequent Contributor
timestamp: June 19, 2016, 06:33:32 pm
content: You can get solvent type glues for acrylic that leave an invisible join.otherwise you could scan the original, retouch and then try something like laser decal paper

author: Andy Watson
author_rank: Super Contributor
timestamp: June 19, 2016, 07:11:07 pm
content: I'm weary of using using any sort of solvent on the crack because it would also remove the painted legend (and I would probably make a complete pig's ear of it).Laser decal? Hmmm, that might work

author: SeanB
author_rank: Super Contributor
timestamp: June 19, 2016, 08:57:23 pm
content: Scan it, fix up in whatever image program is your choice and print on a laser safe photo paper sheet. Then get a cold laminator and use the plastic that has an adhesive on the one side, used to make labels, and laminate it. In the interim make a file to have the holes cut in a sheet of acrylic of the right thickness, tinted if you want, then stick the label on the back side and cut out the holes as needed. You would need to leave cutouts in the backing so the display shows through.

author: bitseeker
author_rank: Super Contributor
timestamp: June 20, 2016, 06:09:46 am
content: If you're going to have a new panel laser cut, you could also have the lettering laser engraved. Either get the panel made from two-layer acrylic (black on white) so the etching reveals white lines/letters or cut two panels, one clear and one black, and have the clear one etched.Of course, you won't have red lettering this way. If you have a steady hand, you could fill the appropriate letters with red paint. I'd probably try illuminating the desired letters from behind with shrouded red LEDs.

author: PaulAm
author_rank: Frequent Contributor
timestamp: June 21, 2016, 01:48:24 am
content: Ugh, getting white lettering on a transparent background is very difficult since most printers do not print white.Most panels are done with silk screen using a white plastic compatible ink. Getting ink to stick to plexiglass is not trivial.You could make up artwork and have somebody with an Alps printer make a decal. Those will print white. Mirror it, apply it to the back of the new plastic and you should be good to go. There are online services for this, you should be able to get it done for a small fee.

author: VK5RC
author_rank: Unknown
timestamp: June 21, 2016, 07:41:34 am
content: It might be worth talking to some of the small display sign writers. I was thinking of laser etched perspex, under lit with LED could look interesting but not original nor cheap I suspect.

author: Andy Watson
author_rank: Super Contributor
timestamp: June 21, 2016, 08:59:19 am
content: Quote from: PaulAm on June 21, 2016, 01:48:24 amyes !I was very keen on the decal idea until I realised that it was the white part that I needed to print. The original appears to have been printed/painted in black leaving unpainted areas for the red and white lettering. The red and then the white layers were printed over the black (the back side is painted white - except for the display area).Thanks for the ideas.

author: rob77
author_rank: Super Contributor
timestamp: June 21, 2016, 09:43:39 am
content: regarding printing white... i usually print a negative image with laser printer onto a photopaper and put it behind a clear acrylic panel - you'll end up with white text on black background. or print a negative to a transparent film and just spray paint the back of the film with white paint - same resultanother option is to use UV curable paint for the white parts.

author: linux-works
author_rank: Super Contributor
timestamp: June 21, 2016, 04:11:54 pm
content: it won't be original looking, exactly, but why not just cut the whole thing all new on a laser and do infill with ink that you like?the secret that I use is to leave the paper masking on while lasering, etch the letters deeply by doing multiple passes or raising the laser bed a click between lettering passes, to dig deeper. leave the masking on, paint with acrylic paint, PUSH paint into voids, repeat until the paint fills the voids. let dry 1/2 hour or more. peel off backing paper, scrape off excess using soft burning tool (fingernail works great!) and you are done.you can print mirror image on the underside if you want better protection and if you use clear plastic.else, I use black, fill with white and it comes out nice and contrasty.you could even have cut-outs for windows and press clear or red or other semi transparent plastic into that cut-out; to do that, you find what the laser kerf width is and add that to the 'lens' plastic when you cut it. try a few sizes until you can PRESS the lens into the plastic and it fits by force of friction.repairing existing will never look good. just create a new one.

author: SL4P
author_rank: Super Contributor
timestamp: June 23, 2016, 06:34:31 am
content: Quote from: linux-works on June 21, 2016, 04:11:54 pmDon't forget to do your etching and filling from the rear - so the front is a sheer surface with color filled lettering. Clear window will be just that - clear.