How to frost acrylic?

[SpazBoy357]

Anyone have any tips on how to give a piece of clear acrylic a frosted appearance? I want to have it so that it's not see-thru but will still pass light from behind it. I know that I could just take a stack of different sandpaper grits and do a trial-and-error thing, but my supply of acrylic is limited (and so is my cash).

Thanks in advance for any help!

[LogAn'sRun]

I've found that depending on the amount of frost that you want, you could 'step' the sandpaper. If you want a really frosted appearance, than lightly sand 80-120grit paper both ways, vertical and horizontal. Do both sides.
If this is too much for you, you can actually 'step back' by going to higher grits, but you'll never attain the pure translucence without flame polishing.

That's pretty much it. The real key is to do both sides of the acrylic and you could even try to 'wetsand' for less visible scratch marks.

[SpazBoy357]

Yeah, I was figuring I would start with a 120 grit, see how that worked, and adjust as needed. But I was really hoping that someone here had done it before and could give me some real-world advice before I started scratching at my few bits of plastic. IIRC, CyberDruid frosted the bases for the WC reservoirs that he built for FlyingA2's rig, but he didn't mention how he did it.

As for "pure translucence", that's the furthest thing from my mind on this particular item, but thanks for the tips, LogAn.

[CyberDruid]

There is actually a spray for that. It's like $5 a can and you can get it at most hobby stores and some HW stores. Just spray the panel.

http://doitbest.com/Spray+Paint-Rust+Oleum-model-1903-830-doitbest-sku-796125.dib

[SpazBoy357]

Thanks for the info, CyberDruid.

Is the spray what you used on the bases for the WC rez's on FlyingA2's rig? I think it was a Cosmos and you put them up on the bars like missiles. Am I remembering rightly? In any case, they looked fantastic and got me thinking about using a back-lit (or side-lit) panel of frosted acrylic.

It sounds a lot easier than sanding away for hours. Does the spray just stick to the surface or does it actually etch into the plastic?

[CyberDruid]

Thanks for the info, CyberDruid.

Is the spray what you used on the bases for the WC rez's on FlyingA2's rig? I think it was a Cosmos and you put them up on the bars like missiles. Am I remembering rightly? In any case, they looked fantastic and got me thinking about using a back-lit (or side-lit) panel of frosted acrylic.

It sounds a lot easier than sanding away for hours. Does the spray just stick to the surface or does it actually etch into the plastic?

No I blasted those parts with media to give them that look. The spray is actually removable from glas...plastic I think it'd be there for the duration. It's a coating.

[SpazBoy357]

Cool. I'll give it a shot.

Thanks again, CD.

[evil-98]

or you can just use a matte clear coat, something similar to what CD suggested but matte clear coat is much stronger

blasting with abrasive media would be the only way i would do it, but all the other suggests will work too

[LogAn'sRun]

Yeah, I was figuring I would start with a 120 grit, see how that worked, and adjust as needed. But I was really hoping that someone here had done it before and could give me some real-world advice before I started scratching at my few bits of plastic. IIRC, CyberDruid frosted the bases for the WC reservoirs that he built for FlyingA2's rig, but he didn't mention how he did it.

As for "pure translucence", that's the furthest thing from my mind on this particular item, but thanks for the tips, LogAn.

Uh, yeah, np m8. But I have done it, so I wouldn't answer unless I kind of knew what the effects would be.
Anyway, the absolute easiest way is just like Cb says, but if you don't have access to that kind of equipment, some elbow grease and 80-120grit does the same job. . .

[SpazBoy357]

@ evil-98 - Unfortunately, I don't have access to any kind of media blaster so I'm gonna have to go low-tech for this.

@ LogAn's Run - I misunderstood. I didn't get that you had done it with the sandpaper. My bad, I apologize.

I think that I'll just bite the bullet and hit it with some 120 grit. If that doesn't work, I'll go to the 80. If I still don't get the look I'm after, I can always try to cover it up with a matte clearcoat or the stuff Cyber recommended. I have a feeling that I should buy a couple more pieces of the plexi.

Thanks for all the help. If it works out, I'll post pics.

[Lsdmeasap]

Please post your results, process and findings with this. I have been planning to do some panels for my mod I am doing, and would like to frost some clear and have Blue or UV LED's behind it for a glow effect

[Navig]

Here's an example where I hit some clear plastic with the spray on frost:

Link here. (http://forum.uabit.com/showpost.php?p=850234&postcount=60)


The nice thing about the spray-on frost, you can control the opacity by additional layers of paint.

I've also done it with sandpaper. You've nailed the important thing. Create test chips and experiment. Unfortunately every brand and make of plastic is a bit different, in terms of surface strength, scratch-ability, and hardness. So results will vary.

navig

[SpazBoy357]

@ a573573 - I'll post when I have something, but I'll warn you: My projects tend to move slowly. Like glacier-slow. Maybe even erosion-slow.

@ Navig - Nice logo! How's it holding up? My big concern with any of the spray-on solutions is the worry that it won't be durable.

[Lsdmeasap]

Not to worry, as do mine!

Been working on a rocketfish at a snails pace! Haven't even made a worklog yet, but have taken some images.

Parts get purchased slow on my end, hence my pace. I do already have my acrylic though, so If I get around to some tests before you post anything I will post mine as well

[Navig]

It sits in a very protected spot. (http://img.photobucket.com/albums/v363/navig/Console%20Project/Final%20pics1/Openandlit.jpg) So durability isn't a huge issue.

It definitely feels solid and doesn't easily scrape off the plastic. The strength subjectively feels like any other primer layer. I suppose you could clear coat over the top to add durability. The benefit of spray on is that there is no patterning or hashing like what comes with sandpaper.

[nelsoncp21]

I actually had purchased the spray and was planning on using it on my windows for my case around the edges. So I too am very interested in the results of this as I haven't donw the windows on my case yet. I had never heard of the sandpaper trick before so it would be nice if someone had a comparison.

[SpazBoy357]

@ a573573 - So we are in a race of snails :D And I haven't even picked out the case yet.

@ Navig - First, WOW! Nice rig. After seeing that one, I followed a bunch of the links in your sig. You do nice work. Very nice work, indeed.

Second, for the project I have in mind the hashing/patterning caused by sandpaper might be a good thing. The best way I can describe the design is that it's similar to the blades of a propeller. If the sanding was done along the blades, it might end up looking better than if there was no "pattern" to the frost. Of course, it might end up looking like crap, but that's what trial and error is all about, eh?

@ nelsoncp21 - If you get tired of waiting and decide to go for it with the spray on stuff, please post pics of how it turns out.

[nelsoncp21]

It's not a matter of waiting. I didn't plan on doing it till I finished painting the side panels first. As soon as I can get the paint to turn out half way decent I plan to try it. Either way if no one else has posted pics before I do mine I will throw some up.

[Lsdmeasap]

@SpazBoy357 - Yeap, Guess so. :D

I have all my main items. Case, Acrylic, Paint, ect Just gotta get started, been kinda waiting on a few smaller items like sleeving, Res, ect and getting my case actually painted before I open the acrylic up