How To Frost Clear Acrylic/Plastic?

[Petseal]

Hello all,
In the past I have used sandpaper to lightly "frost" clear plastic, which works fine on small pieces.
Recently I found some larger blocks of clear acrylic so I am finally able to scratch build some props with larger "frosted" areas. The problem is sanding it is not working, especially since I want to put a light behind it.
Can anyone suggest how to give the acrylic that "frosted" look?
Also, would having the frosted look spread the light more evenly?
With what I have right now I get very little, if any, light spread when I put a bulb behind the piece!

So you know I am building a wall communicator from the original Star Trek series. If you are familiar with it then you might recall that the emergency light appears frosted when off and flashes red when on.

Any help would be very much appreciated!
Later, Petseal

 

[hansicle]

You can buy frost in a can. It's a spray paint that will frost glass. I just used some to frost a small door window at work. I'm sure it will have the same effect on plastic, maybe you could find it in your neck of the woods

http://www.rustoleum.com/CBGProduct.asp?pid=106

Good luck!

 

[kalarcana]

What I've used has been sandpaper in a sanding block. I just sand both sides of the acrylic and it worked for me. I started with 220 grit and then went with 400. I hope that helps.


Rick

 

[nzjedi]

There is an adhesive film product that you can apply to the surface, it gets used on comercial windows as a nonperminant alternative to engraving. Go see a sign writer I'm sure they'll hook you up with a roll. Acrylic generally has excellent optical qualities, it gets used in some pretty awesome physics experiments to catch photons, if you want to illuminte a frosted section, you'd have better luck illuminating it from the side as opposed to the back. I don't know how well the adhesive frosting would work though, perhaps mask it off and try doing it chemically? Use a solvent to burn the sections you want frosted, that way the tiny pits will be in the path of the light more.

 

[micdavis]

Sandblast it.

 

[robstyle]

Sandblast it.

yup yup

 

[kdawg1]

Check the craft store for stain glass paint, they also have the paint to frost the glass and it works on plastic.

 

[Petseal]

Thanks guys for the input. Will give these ideas a try and so what happens!

Check the craft store for stain glass paint, they also have the paint to frost the glass and it works on plastic.

I do have some "stain glass paint" I bought some time ago but never used. (It looks like the paints found in a paint-by-numbers kit) One is white and I wondered why. Do you know what kind of thinner is needed for this type of paint! That's the reason I have not used it as yet, set did not come with instructions :rolleyes
Again many thanks for the input, Petseal

 

[kdawg1]

Not sure but that spray is really thin and make sure the plastic is super clean!!!!!!!!!!:thumbsup

 

[robn1]

Wet sanding, or a clear flat spray.

 

[Petseal]

Found some frost paint at a local hardware store. It looks real good but I can still see through it. Will try a few more coats then I may put a coat of clear red on the back side and light it up. Hopefully that will look OK, if not I will try something else.
Thanks to everyone for the input, Petseal

 

[RGPFX]

Try Testors Dullcote. I use it all the time to frost the windows on model buildings to diffuse light from within. It dries quickly and can be removed if neccessary with common isopropyl alcohol.

RGP

 

[sebmodio]

I saw this on the Leonard Nimoy TV show about props...

Dissolve (epsom?) salt in water then brush onto the glass or plastic. When it dries the salt crystals remain on the glass/plastic.

Maybe? I dunno, it was the first thing I thought of.

 

[Petseal]

Try Testors Dullcote. I use it all the time to frost the windows on model buildings to diffuse light from within. It dries quickly and can be removed if neccessary with common isopropyl alcohol.

RGP

That sound like a great idea and I think I may have some of that around to experiment with!
Thanks RGPFX

I saw this on the Leonard Nimoy TV show about props...

Dissolve (epsom?) salt in water then brush onto the glass or plastic. When it dries the salt crystals remain on the glass/plastic.

Maybe? I dunno, it was the first thing I thought of.

I remember seeing that, I think the idea was to make it look like a window in a haunted house setting! They put it around the edge but I think if brushed all the way across it would give the right look. Should be able to shoot it through the air-brush to eliminate brush strokes!
Thanks Beesa-Pesal, definitely something to look into!

Thanks guys and gals, I am getting more ideas than I know what to do with! :eek
I think it's better to have to many ideas then not enough anyway.
So again many thanks to all, Petseal