I used a polystyrene ball. Much harder and denser that styrofoam.

I used polystyrene, glued it with GEII and had no problems... from what I read at Maryland Mosaics, polystyrene requires no special prep

I think Crystal had tried mosaiking styrofoam once and GEII ate it, so she coated it in a watered down weldbond solution and then used GEII with no ill affects - maybe she'll correct me if I got that wrong

I used a styrofoam ball for my exchange ball. This time I only painted one coat of gold acrylic paint on it. I used both GEII and Welbond to adhere the tesserae. No ill affects. (I probably jinxed it! - watch the darn thing arrived unglued)

This cake is styrofoam that I just siliconed straight to it.

Here is a link that might be useful: {{gwi:129659}}

I recently made a slice of lime out of styrofoam. I gave it a layer of Weldbond first then used Weldbond to adhere the glass to it. I had no problem with it.

I wasn't sure, so I put two coats of Mod Podge on just in case. I used GE II and didn't have any problems.

I used GEII on my ball which was pre-painted polystyrene, worked fine.

BUT...this was after I had tried a product called Amazing Goop, which ATE the ball. Also Krazy Glue has the same basic ingredient as the Goop so that didn't work either.

Be aware that "styrofoam" is that crumbly stuff they stick flowers in. Polystyrene is a much better substrate IMHO. It's the stuff they make ice chests out of, or stuff beanbags with, made into balls (or wreaths, or cones, or whatever.) I found the best source to be Molecular Models something or other...I've lost the link. Just Google it.

I've gone to the ReStore and bought the foam insulation pcs and that's what I used for the cake.

As a group, what a wealth of information all you friends on this forum provide. It's so much fun knowing you have friends here that can help answer these off-the-wall questions. Thank you to each of you that wrote with information. HAPPY SPRING!!!