alternatives to modeling foam

Have any of you come across a more cost-effective alternative to modeling foam? Perhaps something like a floral foam coated in a hardener or body filler?

Perhaps something like a floral foam coated in a hardener or body filler?

Most “alternate” foams are styrene based, and will not survive an encounter with polyester-based bondo, lacquer thinners, paints, and many commonly used spray-on adhesives. It requires extensive measures be taken to protect the underlying foam. Water-based adhesives and fillers will work, but the end result is usually less than ideal, and extra time is required to allow for drying before subsequent operations can be performed (bonding, shaping, etc.). You can slap on a half an inch of bondo and it will kick off in four minutes; half an inch of water-based spackle compound, gesso, etc. is still going to be soft when you come back in the morning. And every little thing to do will be followed by waiting for your fillers to dry. If I’m working to a deadline, the last thing I want is to be constantly waiting for something to dry before I can do something else.

I keep going back to this … generally, labor is more expensive than material, even if you are a student. Maybe … especially if you are a student; how much time do you have to spend on a design project while keeping up on other classes?

Consider: you buy a cheap construction-grade insulating foam at Home Depot … now you have to coat it with something that will protect it from paints and solvents … which means that you will have to buy THAT as well as … spend extra time, and additional materials (brushes, sandpaper, etc) working with it. If you are not 100% complete in coating the surface … if there is the tiniest of crevices that solvent or paint can find it’s way to the foam through … it will dissolve the underlying foam … and you will be back at zero.

There is also the “frustration index” to deal with; i.e., nothing is more frustrating (to me) than wasting a lot of time to get to a point that you could have started from… .

How much are you getting charged for the foam?

From what I recall yellow foam when I was in school was something like $20 for a 4"x12"x12" block.

Design materials can be expensive, but consider it an investment into your education.