foam core?

Squall67584 · Post by **Squall67584** » Tue Dec 09, 2008 1:53 pm

I've seen a few sites that show progress pics on scratchbuilds, and several of them make mention of using foam as a core. Are they reffering to styrofoam, like the kind used in those cheap ice coolers, or something else? It's kinda late for me to use something like this in what I'm building now, but I can use it for future refference.

Kylwell · Post by **Kylwell** » Tue Dec 09, 2008 2:09 pm

They're usually referring to pink or blue insulation foam, available @ most hardware store.

Squall67584 · Post by **Squall67584** » Tue Dec 09, 2008 2:14 pm

You mean that stuff that is like 1/4 to 1/2 inch thich and comes in large sheets? I thought it was something thicker, but I guess it depends on the scale of the model. Pictures can be deceiving to a simple mind...

Kylwell · Post by **Kylwell** » Tue Dec 09, 2008 2:15 pm

You can get it up to 2 inches thick and laminate it with any number of glues (just not CA or styrene cement)

Squall67584 · Post by **Squall67584** » Tue Dec 09, 2008 2:27 pm

Interesting. Wish I would have known about this stuff before I wasted my time and money on a can of that yellow foaming crap. That was definitely more trouble than it was worth. Oh well, live and learn.

Johnnycrash · Post by **Johnnycrash** » Tue Dec 09, 2008 3:03 pm

Kylwell wrote:You can get it up to 2 inches thick and laminate it with any number of glues (just not CA or styrene cement)

You can get it much thicker. Look for Buoyancy Billets. They come in at least a 7" thickness. I have seen thicker, in the 12" to 16" range. They are used to make floating docks. Same stuff though.

Kylwell · Post by **Kylwell** » Tue Dec 09, 2008 3:22 pm

Johnnycrash wrote:
Kylwell wrote:You can get it up to 2 inches thick and laminate it with any number of glues (just not CA or styrene cement)
You can get it much thicker. Look for Buoyancy Billets. They come in at least a 7" thickness. I have seen thicker, in the 12" to 16" range. They are used to make floating docks. Same stuff though.

*smack* forgot about those.

Chacal · Post by **Chacal** » Tue Dec 09, 2008 9:47 pm

And they're all done basically with (sort of) the very same goop that comes in a can. They pour a bit (well, a lot) of the chemicals in big molds and cut the 'slices' away. Technically, you might order a whole big ol' block of it, though it won't fit in a minivan.

Johnnycrash · Post by **Johnnycrash** » Tue Dec 09, 2008 9:56 pm

But you could carve a van big enough to carry it. Oh, wait...

Kylwell · Post by **Kylwell** » Wed Dec 10, 2008 12:54 am

5 Axis carved a full sized Deora II out of foam....

Lt. Z0mBe · Post by **Lt. Z0mBe** » Wed Dec 10, 2008 1:05 am

Also, for filling in areas between bulkheads, you can get thin sheets of it found in packaging materials used for electronics. The reason I mention this is these materials are plentiful this time of year with all the gifts. (Cue Matthew Lesko) It's sometimes a little less dense, but more than adequate when you're using it as filler in large sculpts. I used it for the walls in my A.F.S. and N-1000 display bases' groundwork.

I hope this helps.

Kenny

photoguy · Post by **photoguy** » Wed Dec 10, 2008 9:50 am

Theatrical props and sets, prototypes, R/C model airplanes...

Glue it together with liquid nails, fill with spackling compound, sand it, cut it, hot wire it,seal it with acrylic sealer, Foam is great stuff!

Antenociti · Post by **Antenociti** » Fri Dec 12, 2008 2:11 pm

Squall67584 wrote:I've seen a few sites that show progress pics on scratchbuilds, and several of them make mention of using foam as a core. Are they reffering to styrofoam, like the kind used in those cheap ice coolers, or something else? It's kinda late for me to use something like this in what I'm building now, but I can use it for future refference.

this might help; http://www.barrule.com/Workshop/images/ ... /index.htm

its generally extruded polystyrene (styrofoam, foamular etc), just varying in density and colour - but there are other "foamed" alternatives such as balsafoam (phenolic foam) and even foamed-pvc (sintra, PALIGHT etc)

the key for modelling is density as the denser it is the stronger it is - dense 'closed-cell extruded polystyrene' above 32kg/m3 i'd suggest is a minimum, although if you are going to pressure cast something then better go for something higher 70-100kg/m3.

surf-boards blanks and flotation foams are as much as 200kg/m3 density and you can drive a car over them without leaving an imprint.

Wish I would have known about this stuff before I wasted my time and money on a can of that yellow foaming crap.

yeah thats a real nasty sticky exothermic expanding polyurethane resin and a real beotch to work with - best avoided for many reasons imo.

KLINGON CAV · Post by **KLINGON CAV** » Sat Dec 13, 2008 3:43 am

Are the Buoyancy Billets capable of being used for vacuform shapes?

Rafael · Post by **Rafael** » Fri Jan 02, 2009 5:59 pm

I live in banana-land. Far away of everything model-related. I can't find decent models and/or model shops here, and buying from internet is almost a political-economic sin here.

So nothing of that stopped me in my quest for having fun, and recently I "discovered" expanded polystyrene, the one made up of little balls of foam as a modeling media. I'm still honing my skills with this, but so far, my first build are these, and they were fun to make:
http://i132.photobucket.com/albums/q14/ ... G_4327.jpg
http://i132.photobucket.com/albums/q14/ ... G_4328.jpg
http://i132.photobucket.com/albums/q14/ ... G_4329.jpg
http://i132.photobucket.com/albums/q14/ ... G_4330.jpg
http://i132.photobucket.com/albums/q14/ ... G_4331.jpg
http://i132.photobucket.com/albums/q14/ ... G_4332.jpg
http://i132.photobucket.com/albums/q14/ ... G_4333.jpg
http://i132.photobucket.com/albums/q14/ ... G_4334.jpg

All made from said foam, sealed with white glue and then filled/surfaced with what passes for bondo here.

Saludos, and happy modeling

Rafa

en'til Zog · Post by **en'til Zog** » Fri Jan 02, 2009 8:13 pm

Most excellent!

It's not what you start out with, but how you end up that counts.

Model ON!

Scratchawan Learner · Post by **Scratchawan Learner** » Sat Jan 03, 2009 4:20 pm

Foam sheeting is available from any decent homebuilder's supply store,
I.E. Lowe's, or Home Depot, etc. I picked up at a plant once, where they cut large blocks of foam to use in concrete casting, for bridge pilasters, and beams... these foam blocks were gigantic! Some of these blocks were four feet by five feet, by twenty five feet long! I don't recall the manufacturer's name... but they specialized in Styrofoam extrusions...and offered custom densities. All the foam blocks were cut with HUGE hotwires. BLocks simply made their way down a production line conveyor system...and then into the hotwire machine, which was operated in much the same way that a CNC machine works. VERY precision oriented.
I remember thinking of the fun I could have, with one of those machines...and a dumptruck load of greeblies!

I should note, that the Styro sheeting works best, when one uses a couple of sheets of acrylic, to provide a "spine" and "ribs" to provide a readymade planform... one fills the styro, in between the contoured ribs... and sands the corresponding shape, until everything is even.... Greg Jein once did a great article on how that's done. This is the method he used, to build the prototype shapes, for the Enterprise D, on the STTNG miniatures.
This method results in a strong, and reasonably light master, that can withstand the rigors of turning this way and that... especially if the miniature has been properly "skinned" with fiberglass, for strength.
One can then add a layer of bondo... sanding carefully. Bondo contains styrene resin...and is a great means of making sure your greebly details stay secure on your miniature.
Scratch

max142 · Post by **max142** » Sat Jan 03, 2009 5:38 pm

Very good article using the foam and bulkhead method. It's very good but, Dave's humor and opinion are rather strong (he's trying to get people off their butt)
http://www.culttvman.com/scratchbuilding.html

Scratchawan Learner · Post by **Scratchawan Learner** » Sun Jan 04, 2009 3:27 pm

Ah, yes... the inimitable David Happyfellow...

Where would the modeling world be, without him?

I like his modeling methods... he's very knowledgable.
I also like his models, and his attention to minute detail..
Now if he'd just pay as close attention to his people skills...
But that would be implying that Dave cares what other
folks think... and we couldn't have that, now could we?

Scratch on, friends!

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foam core?

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