[theVanyr]

Back in the day... which is getting disturbingly far back lately... before I had the budget for such things as solding irons and hot wires - I seem to recall spraying the foam insulation (blue or pink - you choice) with spray paint to purposely melt back the foam around a stencil to create a relief...

Now my memory is a little dim on the detail... jokes aside I think I was 11... Have things changed? Do they coat the sheets you buy in home despot these days to prevent such chemical interactions? I know/remember one needed a light touch with the spray can, I just want to make sure the laws of physics still apply as I remember them, before I help/inflict my freind in her first yard prop construction.

btw - what the heck DO you paint foam with.

 

[Homestead Haunt]

Yes, spay paint will still eat away at the foam as will acetone misted from a spray bottle. I recommend testing on a scrap piece of foam. Paint the foam with latex paint or Drylock for that concrete look.

 

[FirstSpartan]

Yep the spray paint still works to eat away at foam. Homestead Haunt has good info above too.
I actually have a couple of pics with the melting foam of a tombstone in progress that I'll post. I think I used some cheap clear matte sealer spray paint from HD.
Some of the thinner sheets of foam may have a thin layer of plastic on them that has to be pealed off tho, fyi.
I use primer then Dryloc then exterior latex paints to give it a weathered look. For carving I use a hobby wood burner, razor blades and a dremel. Misting the tombstone with water and using a blowtorch over it will give you some interesting effects also.
Sounds like you have some fun times ahead! Good luck

 

[theVanyr]

thx guys - back to the foam props I go.

 

[fravak]

It's pretty obvious if the foam has a protective coating on it. The 1/4" stuff they sell around here has it, but the 1" and up stuff doesn't.

I've used the clear sealing spray like FirstSpartan. Never thought about using acetone from a spray bottle...

I paint my foam using both latex house paint and acrylic craft paints. I have also used powdered iron and rusting solution I got from Michael's to make metal items like sword blades.