Where to obtain foam?

Pot scubber from a dollar store.  Cost a dollar, of course.  Cut the pieces off as you need them.  

Hey buddy , when the wife isn't looking unzip one of the cushions from the couch. Pinch off a hunk of foam from the backside. 

Don't mention FS Magazine if you get busted. 

MonsterZero

I would like to try using foam as a paint applicator for applying the "chipping" effect. Also, it's useful for plugging various holes in the model when airbrushing.

Problem is I'm not sure where to obtain foam of appropriate consistency. Occasionally you purchase a product and they use grey foam as packing but generally I don't have any foam lying around the house.

 

HomeDepot/Lowes/Ace/etc.   all have sea sponge in their paint accessory departments for applying fancy paint finishes.   For that matter try Michaels/HobbyLobby in the craft paint sections for sea sponge.   Sea sponge is neat because the holes are various sizes and results in a more random splotch than does packing/upholstery foam.

Sally Beauty Supply (or other makeup source) has makeup application sponges.   These are triangular-shaped sponges which will allow you to get into tighter spots.  They are a bit tighter cell structure than packing/upholstery foam.    While you're in Sallys check out their sanding sticks.   Cheaper than ones with a model logo emblazoned.

For masking cockpits, exhausts, etc.  I use foam ear plugs.  Again a hardware store item.  You roll them up and put them in place.  They slowly expand (about 5 minutes) to fill the area with a soft yet firm masking.   Better yet, they are reuseable.

Keep your head on a swivel.   Look for everyday objects, or objects sold for other purposes.   They will often have applicability to the modeling hobby.  Often at a lesser price.

I picked up a package that had two pieces of about 1" thick soft foam, around 16" square at Walmart.  Used for chair pads, and in the fabric section.  IIRC was under $5.  Pretty consistant in the size of voids in it as well.

I'll use the foam that comes in Eduard or Aires resin sets. It cuts nice and seems to conform to odd shapes nicely. Some foam just seems to crumble.