Hey, those of you casting buttons, have you checked out Cyro? They have some compounds that are supposed to be really good for light diffusion ("Acrylite DF"). Dunno if they can be used with cold casting or not. I'd give direct links to the products, but their site uses session cookies heavily and I didn't feel like reverse-engineering the URL to make a simple link. Just click on FAQ and enter "Diffusion" in their search engine...

Just checked into it the only diffusing acrylics they listed on one of the distributor pages were in pellet form... this is for high volume industrial use... not sure if we could do anything with this.

I did find this

These are opaque pigments but I could possibly mix this in a small quantitiy to achieve a milky white color. I'm going to call them and ask... they also have a glow in the dark pigment that might be kind of funky!

On a side note, I hate to keep dangling this out here, still fighting the battle of bubbles, I tried to take a picture but they didn't show up, kind of hard to explain... anyway the last few weeks have been a bit busy for me. Works been hell with the lovegate virus, I just started a new kenpo class, and been helping a friend slowly move everything they own... anyway.. hopefully in the next few weeks I can get the button show on the road.

Just got off the phone from placing an order... I got the following colors

glow in the dark whitish green (thought this might be cool to put behind the clear plastic for diffusion)
regular white (for defussion)
royal blue
bright red
lime green

All for under 30 bucks!

Also asked the guy about my bubble issues... he said you never degass liquid plastics... always pressure cast this might be my problem!

he said you never degass liquid plastics... always pressure cast

So what was Brian doing, then?

I got the following colors

I was thinking it would be cool to get some kind of black pigment too, so you could mix it with white and do a milky gray. That would give you gray buttons in the daylight, just like the original design, but then they could glow gray or (with a little coloring over the LED) colored at night.

And I just realized that I posted this in the wrong forum. I shouldn't be putting on-topic stuff in the off-topic forum. Maybe I'll graft this thread over to the General forum.

So what was Brian doing, then?

Brian lives in a less humid climate and never had to do any of this crap

They had black too, didn't think to order that though

I shouldn't be putting on-topic stuff in the off-topic forum. Maybe I'll graft this thread over to the General forum.

I wondered about that, but I figured "hey, he's Tony! He'd never post anything in the wrong place!

Hi, if the bubbles are on top or near the top, this may help. I was looking at pictures of your molds and noticed that you don't have any sprue holes. I used to cast plaster with rubber molds. I'd put sprue holes in the mold so that when casting, the top side would have extra room for the bubbles to escape. Below is a simple example.

http://www.micromark.com/part_mold.html

The stuff that I was doing was relatively small. I'd use a 60cc syringe and lancet needle to inject the plaster. If, after trial and error casting, I saw bubbles forming where there was no sprue hole, I'd stick a lancet needle into the mold flush with the interior of the mold to act as a sprue.

I've tried to cut and burn holes through the rtv rubber without luck but the needles punch straight through it. I bought the hypodermics and needles at a farm store that catered to dairy and horse farmers.

Best of luck.

Interesting idea. I think Brian may have used sprue holes, too.