Test marker pens on a PET bottle instead of a Plexiglass transparent-board? - Page 1
Forum section: electronics / general

author: RoGeorge
author_rank: Super Contributor
timestamp: April 20, 2020, 11:01:42 am
content: I have a piece of transparent plastic with UV LEDs on the edges, about 1m (3 feet) diagonal, 5mm (0.2 inch) thick.I guess it was a DYI transparent board meant for shooting video lessons, the type that can be written with color markers that fluoresce while the UV LEDs on the board's edges are on. No idea what type of transparent plastic it is made of, could be "Plexiglass" or could be "Lexan", IDK how to test.I want to suspend it against a white wall, to improvise a small whiteboard to scribble on. Already have various markers, permanent and highlighting color pens, none of them are dry erase pens.The idea is to use what I already have, but without permanently taint or scratch the transparent board. It's for the lab at home, so no intense or public use.I really don't want to damage that transparent sheet, because in case it's not suitable as a whiteboard, then that plastic sheet will be ideal for making some transparent boxes.- How can I test which pens are safe to draw/erase?- Is it safe to assume that those pencils working on the plastic of a PET bottle will work on the plastic of the transparent board, too?- Would a dish-washer sponge leave scratches if used as eraser? Any personal experiences/advices with transparent boards?

author: Kleinstein
author_rank: Super Contributor
timestamp: April 20, 2020, 11:28:07 am
content: Different plastics can react different to the solvent in the pens. So one would have to test with the same material.One could test upfront if the pens react to the UV light.

author: jogri
author_rank: Frequent Contributor
timestamp: April 20, 2020, 11:44:27 am
content: Quote from: RoGeorge on April 20, 2020, 11:01:42 am1) By getting another sheet of acrylic glas and testing your pens on that2) absolutely not, PET is rather stable against organic solvents but acrylic glas will be destroyed by almost all of them (Polycarbonate/Lexan is a bit more resistant, but i still wouldn't use it as a whiteboard)3) again, get yourself a second sheet of acrylic glasEDIT: Why it is important that your whiteboard is stable against organic solvents: Your pens are basically ink dissolved in some sort of organic solvent (probably an alcohol/acetone), if you draw with them the solvent evaporates, leaving behind the ink that sticks to your board-> the solvent from the pen can destroy the surface finish of your board

author: RoGeorge
author_rank: Super Contributor
timestamp: April 20, 2020, 12:18:19 pm
content: I see, thank you. Since different plastics can react different, and this is the only sheet I have, I'll just use it and see how it goes with time.At worst, it'll just end as artistically-scribbled smudge-colored boxes instead of transparent.

author: beanflying
author_rank: Super Contributor
timestamp: April 20, 2020, 12:34:27 pm
content: There are some rough and ready ways to identify Plastics. One examplehttps://www.twi-global.com/technical-knowledge/faqs/faq-how-can-i-easily-identify-a-plasticso you could consider shaving some bits off the sides for a test. I have used a similar process pre Laser cutting some plastics.A lot of the permanent markers traditionally used Xylene as a solvent but some of the newer uber permanent ones use some other nasties. Some of the Whiteboard and Chalk types use IPA as a solvent so should be easy to test

author: Gregg
author_rank: Super Contributor
timestamp: April 20, 2020, 05:23:32 pm
content: You might want to put a thin layer of glass over your plexiglass. Any window company can help you get it tempered if you are concerned about breakage.

author: rdl
author_rank: Super Contributor
timestamp: April 20, 2020, 08:08:48 pm
content: I've used "Sharpie" brand markers for decades. Never had a surface damaged by one. They clean off easily with isopropanol or ethanol, which don't attack most plastics. They can leave a faint stain after cleaning which depends on the porosity of the substrate. Best thing I've found for cleaning is microfiber cloth. If you can buy some dry erase markers, that's what I'd try first.

author: jogri
author_rank: Frequent Contributor
timestamp: April 20, 2020, 10:15:24 pm
content: You could also put a layer of transparent self adhesive foil (like the one you can use to protect school book covers) on top of your acrylic glas, that way you can just peel it off and use a new sheet once it gets scratched/milky. But you should definitely test if it can be removed without leaving some traces of glue behind as you can't use solvents to get the glue off.