Blue Foam model making

Does anyone know of any online tutorials on making blue foam models? I’ve always been a yellow foam guy, but need to make the switch. What I’m looking to find out is what grit sandpaper to start with and work up to (yellow foam is much more forgiving in this respect), as well as finishing and painting blue foam & what materials to use for that. Any tips would help.

Also, if anyone could recommend where to get a good hotwire, that would help, too. I’m planning on making one from a soldering gun, like they posted on this site a while ago, but also want to get a larger “tabletop” wire.

Of course, I’ve done a google search and turned up some info, but I’m hoping for some info & recommendations directly from IDers.

Thanks in advance!

why blue foam?! Price maybe. Anyway, make sure you seal it well with wood filler, spackle, many coats of gesso if you want to keep the texture, before you do any spraypainting, many paints will eat it up like wet cottoncandy.
I’d try to get as close as you can with the wire-cutter first, then use a file. You can get sharp details just using an exacto. I dont’ think sandpaper works very well with it, too porous. It’s been a few years since I’ve used it so someone else may have more up-to-date info if there are newer bluefoams. The main thing is that if you’re using it for any presentation, you’ll have secondary operation work to do on it. Also the debris has more static cling, gets over everything. I only used it for models just to show general size and fit or as building blocks.

It’s been awhile since I’ve worked with the stuff. I’m assuming that you’re not trying to achieve a super-tight, high-gloss finish, presentation model…if that’s the case, you’ve got you’re work cut out for ya’ :smiley:

With that said, I usually made my big cuts on a bandsaw, then did most of the rough shaping with some of the drywall rasps. From there, use a 60 grit paper to smooth things out. Then maybe another pass with 100 grit to tighten your lines up, and get a ‘smooth’ finish.

If it needs to be painted, I’ve only used latex paints. Usually a coat of Killz primer, followed by the latex color of your choice!

Me personally, I’ve always found something nice about seeing just a well constructed blue foam model, nicely sanded, without paint, etc. Blue foam was never intended to be a final model material, and keeping it raw just has more of an ‘in progress’ kinda’ feel.

Me and Blue foam were never that friendly.
really didn’t like making models from it.
With the hotwire cutter, depending on the temperature and the foam used (Pink and Blue are slightly different) it’ll leaver a hard crust (from melting). And it makes it harder to sand.
After cutting with hotwire, bandsaw or mill(Dremel works pretty well to core out pieces if a mill is not available)
Used a wood rasp if necessary.
I used 220 (if i remember correctly)
Hardware stores also sell these sanding foam pads, which conform to the shape.
Don’t try to take off a lot of material with those, rather use them for finishing.

Gluing, the contact cement (LePage 7, pres-tite green, professional quality)
100% solvent-free, no toxic fumes, non-flamable works really well.

I’ve only used bluefoam for mock ups for ergonomic and mechanical testing. It’s good for scale and proportion, but never a final model. For really quick way to get a general form, I use rasp… the small one with a handle that fits your hand, not the long tubular ones.

this is a great site, he uses yellow foam

whats the difference, i use blue foam???


…as i recall, blue foam is much less dense than yellow…more air, less material, dents easier and it has to be filled more for a smooth finish…but the color is not really the determining factor…there is a pink modeling foam available in 4-40lb per cu ft densities…10-15lb is about as low as i would go…