Carving foam

[Beltramidave]

Trying my hand at carving styrofoam in hopes of making an outdoor sign. I just finished my first carving using 2" pink foam from one of the big box stores. I was pleasantly surprised at how well it carved considering I was using a old 1/4" 4 flute tapered bull nose bit. I did find that it left a few "fuzzies" mostly on the vertical edges, but I took my heat gun and quickly re-melted them back down (worked amazing). Not knowing what to expect, I ran my Bosch Colt on 4 and a carving speed of 90IPM doing this in one 3d finishing pass.

I am looking for advice from people who have done this before as to how they go about finishing it so that it can be used outdoors. I have seen a product called Foam Coat that can be applied over the foam to enable it to be painted. I know that if you use the 'real' sign foam that you can paint directly on it, but I am looking for a cheaper option to get started. For starters, I just want to get the foam to a wood color look and from there, maybe add some color to the objects (once I figure out how to use a air brush).

https://www.dropbox.com/s/n5tudoeuxoeyt ... R.jpg?dl=0

Thanks for any advice.
Dave

[GregP]

Sharp bit, less flutes, highish feed rates- all good. I've used latex house paint with some success. I've only used styro for Temporary signs.

[Beltramidave]

Greg,
Did you do anything to the foam before using the latex paint? What about sealing afterwards?
Dave

[Mobius]

I made a gaming table out of that pink foam once. After cutting, I drenched it in watered down exterior grade wood glue (to the consistency of latex paint). This sealed it, allowing me to paint it with whatever I liked afterward. It also toughened up the surface, making it more durable and less prone to damage.

Not an outdoor sign, but something that may work for you?

[mikeacg]

The front of my house/shop is all made of blue foam. I put a coat of exterior primer and exterior latex on it all (though I did use rattle cans for the fronds and toucan color). It has been out for 3 winters (and we are talking Michigan's UP) so far with no degradation...

Mike

[Beltramidave]

The front of my house/shop is all made of blue foam. I put a coat of exterior primer and exterior latex on it all (though I did use rattle cans for the fronds and toucan color). It has been out for 3 winters (and we are talking Michigan's UP) so far with no degradation...

Mike

That is awesome, Mike. Sent you an email.

Dave

[GaryR6]

Clever boy, nice front.

[tvannaman2000]

I've used the pink/blue foam for years in my Halloween prop making. That stuff is great. I've used epoxy to harden it up (although the glue soak thing sounds good), used both latex and spray paint on it and used 'monster mud' (latex paint mixed with joint compound) to cover it. I used the spray paint to texturize the foam to a stone look since it eats away small amounts. I've hand routed lettering with no problems and used a soldering iron to simulate cracks. Now that I have my CNC machine, I use the foam to test run some jobs to prevent bit breakage as I'm getting to learn about feed rates and depth cuts, etc. I'll also probably use it for interior signs as it's lightweight and just easy to work with, yet as rigid as you need it to be as long as it isn't bearing any support weight. A great wood substitute in many areas.

Tim.