modeling an explosion

[Falcon5768]

Im looking to build a diorama of a battle between the Earth Forces and Zion from Mobile Suit Gundam and I want to model a explosion splitting one of the ships apart but I am not sure how to go about it.

Has anyone seen any models dipicting something of a explosion actually going off (and thus a gas cloud) or might know what I could use to make it look like a gas cloud?

[DennisH]

I'm a little fuzzy with the memory at the moment, but I think I recall seeing what you're looking for in pics from Wonderfest from a few years ago.

Big ball of flame and smoke and all sorts of WOW!

Sorry I can't be of more help. Maybe someone knows the model I'm thinking of????


Dennis

[DasPhule]

Expanding foam, the kind used to fill cracks in walls. Experimentation will be required, but that's what the Shadow ship diorama was made from that was at WF a few years ago. Find out who did the dio and ask him. I don't remember who did it, maybe someone here knows? Maybe he's here?

I'm going to try it myself one day, but not until I'm back in a permanent workshop.

Erin
<*>

[Jagdson]

For smaller subjects like my BattleTech figures, I've used cotton fibers to decent effect. Pull apart a cotton ball and glue it in place with white glue. If you're really delicate you can paint sections of the cotton. It's not perfect, but it's not difficult either.

[en'til Zog]

You might try a fluffy ball of cotton or synthetic fiber-fill to create an explosion 'cloud'. Add some debris made from something very light - like stryofoam painted up. Put all this around a few white LEDs, and 'clock' or blink the LEDs with a 4060 chip, or use self blinking LEDs. The LEDs should blink in very quick multiple pulses.

That might work well.

MODEL ON!

[DennisH]

http://www.starshipmodeler.com/events/w ... _shad1.JPG

Google, man's best friend. I plugged in the words "Wonderfest shadow" in Google Images and there you go. Funny thing, it's at some website called Starship Modeler. Man, I tell ya, that place has got everything .

Pretty cool, huh?


Dennis

[Devin]

Interesting thread. I'm in the process of working up a diorama of a WWII ship in 1/350 burning heavily. I never would have considered the expanding foam. Very effective in that Shadow diorama.

-Devin

[Falcon5768]

lol I googled it and got another website with more pics.
http://www.scififantmodmadrealm.com/Won ... 002-6.html

Yeah it might be a bit tough making it a even ball (since its space and all and a anime type explosion to boot.) But it has given me a good idea that what I was thinking of doing might work.

Now to buy the models from HLJ. Thankfully they are the cheaper 1/1200 scale ones so in totall they wont go past 10 bucks for all three, and I might buy a fourth just incase and to get a few more mini mobile suits to chop up and have parts floating with.

[Mr. Badwrench]

Yeah it might be a bit tough making it a even ball (since its space and all and a anime type explosion to boot.)

I wonder if you sprayed it into a balloon if the goop would form into a sphere?

[Shinnentai]

Possibly. The issue would be the urathane foam gluing itself to the baloon rubber.

Maybe build it in stages? Spritz a little wad of foam onto a sheet of paper, then after it's cured, tear the paper off and spritz a little more on the flat side. Lather, rinse, repeat, turning the wad of foam as you go....

I think I remember something about the spray can foam being somewhat shapable/smoothable with a wet (gloved) finger while it's still expanding and skooshy. Not sure though.

[naoto]

Hmm... how long does the foam take to solidify? Is it less than 20 seconds? BTW, does anybody have access to the NASA's KC-135 (aka "Vomit Comet") to try this out? Failing that, some a-grav field generators and an appropriately modified inertial damper module might work. Another method would be to use Cavorite.

[Jonas Calhoun]

I know the 2 part epoxy foam is carvable...

www.publicmissiles.com has some.

Dan

[Go Flight]

Possibly. The issue would be the urathane foam gluing itself to the baloon rubber.

Maybe build it in stages? Spritz a little wad of foam onto a sheet of paper, then after it's cured, tear the paper off and spritz a little more on the flat side. Lather, rinse, repeat, turning the wad of foam as you go....

I think I remember something about the spray can foam being somewhat shapable/smoothable with a wet (gloved) finger while it's still expanding and skooshy. Not sure though.

I too saw (and saved) the pics of the Shadow explosions for reference. It's an excellent job!
I would think that was not all done in one shot. Maybe once the skin has formed over the expanding foam you can try and shape it. I have a different type of project that I was planning on using this technique. If my weekend isn't too hectic I'll buy a can of foam and give it a try.
But is the artist of that dio here? Maybe he can come aboard and give a little how-to.

[Lt. Z0mBe]

There was a diorama I remember from a Wonderfest loooong ago. It may have been back in the 1930's. At any rate, it was a huge diorama of Spider-man fighting the Green Goblin. The Goblin was riding his little sled thing, suspended only by a continuous circle of engine exhaust and smoke eminating from the burner cans of the sled. The exhaust was basically foam, looking as though it transitioned from pure flame to smoke as it exited the sled.

You might try Google for images of the diorama. I know someone has to have images of it.


Another idea for you would be clear casting resin. what about starting with an airbrushed cotton swab. Feather it out slightly, and dip it in the resin. Let it dry and repeat several times. Perhaps this would give you a kind of flame/smoke look. I've never tried it, but it might be worth a shot.

Kenny

[Den23]

I just happened to be experimenting with this 1-component foam. I took a lob of clay, sticked some solid electric wire in it and spout foam on it. I want it to be more 'bubbly' in the next experiment, but it's gonna be hard. It's not like sculptable or something. Maybe building it up more would do the trick. The cool thing with foam is that you can stick things in it later, like debris 'n stuff, being thrown into oblivion.. darn. If there is foam that would be a bit more see-through you could plant some leds in it too!
This is a good example too [http://www.phoxim.de/marco_scheloske_th ... child.html]

[erredois]

some ideas at:

http://www.youtube.com/watch?v=TUbVOr1qmhA
http://halo3.com/believe/shell.html

[unsc shipworks]

Possibly. The issue would be the urathane foam gluing itself to the baloon rubber.

Maybe build it in stages? Spritz a little wad of foam onto a sheet of paper, then after it's cured, tear the paper off and spritz a little more on the flat side. Lather, rinse, repeat, turning the wad of foam as you go....

Yeah, this stuff slowly expands over a couple of hours, so I usually experiment with building up fireballs in stages. Since those cans clog themselves right up and are worthless by the end of the day, I try to build up as many fireballs as I can (usually with the leftovers from a home improvement project). Sometimes it helps to stick little toothpicks or other rigid objects in to help shape the fireball, otherwise it just kind of flops over into a somewhat flattened blob.

As far as smoke effect...I never had good luck with cotton, but that poly-fill stuff that they sell at craft stores to use in pillows and stuffed toys is great! It holds it's shape better than cotton and takes enamel spray paint pretty well. I spray a coat of yellow, then when it dries for a while, twist it around a bit and spray red (gotta saturate it so that no white is showing), then fluff it up a bit and spray black and gray. Play with it a bit and you'll see what I mean, it's fun to work with, and one bag of that poly fill lasts a long, long time. Plenty left over for the kids' school diorama projects, Halloween spider webs, Christmas decorations, etc, etc.

[Kolschey]

Here is a question.

Is there anything that would serve as a resist for the expandable foam?

Certainly when casting, there are substances that are used to make it so that the filler does not adhere to the mold. If you have a spherical mold properly treated, I wounder if that might work.

[NNYGamer]

Check out http://www.starshipmodeler.info/contest13/dio_05.htm too

[scottgirvan]

That explosioni is really awesome. I've read that the kaBooms in Believe are internally lit. Hence the nice glow. I'm gonna pick up a can of foam and try it out tonight. I'll post some pics.

[Kenny]

That explosioni is really awesome. I've read that the kaBooms in Believe are internally lit. Hence the nice glow. I'm gonna pick up a can of foam and try it out tonight. I'll post some pics.

I have made about 7 explosions, the first two now look cartooney to me. On the last 5 which are in a model I'll save for a later comp, I spent a lot more time making them.

In responce to a couple of earlier points, the foam expads very evenly resulting in fairly complete spheres, squirt a glob on to silicon baking paper and when it's mostly set (wet touch test) pop it off and turn over, nice oval spheres.

The best resuts I got was by making the bulk then slowly adding small drops of un-expanded stuff with a wet tooth pick, which then expanded to look really realastic after heaps of applications. And for once you should play with the foam as it drys, poking it with dry toothpicks, gives a much more realistic surface.


AND AGAIN PRACTICE PRACTICE PRACTICE before adding to kit parts.

[Go Flight]

Here is a question.

Is there anything that would serve as a resist for the expandable foam?

Certainly when casting, there are substances that are used to make it so that the filler does not adhere to the mold. If you have a spherical mold properly treated, I wounder if that might work.

IIRC from Marco's WOTW dio, he used low expanding foam over a styro ball and wires. He put the foam can tube down over the wire and just gave it little shots pulling bac until the wire was covered. The low expanding foam will give you more control

[Marco Scheloske]

Here is a question.

Is there anything that would serve as a resist for the expandable foam?

Certainly when casting, there are substances that are used to make it so that the filler does not adhere to the mold. If you have a spherical mold properly treated, I wounder if that might work.

IIRC from Marco's WOTW dio, he used low expanding foam over a styro ball and wires. He put the foam can tube down over the wire and just gave it little shots pulling bac until the wire was covered.

More or less.

You can see the result here http://www.starshipmodeler.info/contest13/dio_05.htm , as already posted. I described how I did it in the text, here is the passage:

Second, the explosion: It was more difficult to "sculpt" this than I thought at the beginning - my first tries looked good at their start, but fully cured they just looked like crazy balls, not like an expanding cloud. This one has a core from styrofoam with wooden sticks attached to it. I used less foam than on my first tries, and when an area becomes to smooth while curing I worked on it with a toothpick (this is the most important part: You must make sure that the surface will not become too smooth). The “arms” are toothpicks, too, covered with just a little bit of the foam. I did this after the main cloud was fully cured.

The paint job consists of three basecoat layers of bright white, sprayed out of a rattlecan. All other colors are from Citadel / Games Workshop in the following order:

A full layer of “Bad Moon Yellow”. Some white spots where not covered, they simulate the real HOT spots of the explosion.
A drybrushed layer with “sunburst yellow”.
A drybrushed layer with “golden yellow”.
A drybrushed layer, using a very stiff, flat-ended round brush of approx. 8 mm diameter with “Fiery orange”.
A drybrushed layer, using the same brush as in 4, with “Blazing orange”.
A last layer with drybrushed spots, using the same brush as in 4 and 5, with “Scorched Brown”.

The paintjob is essential, use many, many, many colors. I`ve seen some done with only 3 or 4 colors, they looked a bit cartoonish.

Good luck!

[scottgirvan]

Bought some expanding foam and tried it out. Here are the best 2 from about 50 globs. Once they set up for about 5-10 minutes I poked them with a sharp stick. It bursts the outer crust that forms. You can easily over do this and end up with a pancake. or wait to long before the poke and just dimple it.

On some of the bigger globs I burst it and then rolled it up like cotton candy. It compacts into a small ball but not perfectly round. I am going to try it again with low expanding foam as well.

http://www.girvanmedia.com/atat/atst/boom.jpg

[Marco Scheloske]

Maybe this picture will help, it is my explosion without color, close-up:

http://www.phoxim.de/marco_scheloske_th ... hild01.jpg

You didn`t use a core from foam, did you? That helps to prevent that the foam-glob will become a pancake while you form it with the stick.

I didn`t wait to use the stick when I did mine, I uses it all the time while the foam cured, carefully watching if an area will become too smooth - then it got a peak with the stick. I did this until the foam was completely cured, approx. 30 - 40 minutes.

[scottgirvan]

thanks, no i didn't have any styro spheres to use. I'm gonna pick some up. your photo is great, thanks, and the tips too! This method will be an asset to many modellers. It's relatively inexpensive too.

Did you use the regular expanding foam or the low expansion variety?

[Marco Scheloske]

thanks, no i didn't have any styro spheres to use. I'm gonna pick some up. your photo is great, thanks, and the tips too! This method will be an asset to many modellers. It's relatively inexpensive too.

Did you use the regular expanding foam or the low expansion variety?

You don`t need styro spheres, just a piece of styrofoam as a core. I broke some from a larger sheet, irregular in its shape.

I used regular, 1-part expanding foam. Nasty stuff, sticks everywhere...

[scottgirvan]

Ah, i have lots of that kicking around. Yeah it's really sticky. I'll try it again soon. So you just shot a small amount on the styro. Did you have to 'move it' with a stick or something to get it to cover the styro. I assume you had the styro on a wire up in the air.

[Marco Scheloske]

Ah, i have lots of that kicking around. Yeah it's really sticky. I'll try it again soon. So you just shot a small amount on the styro. Did you have to 'move it' with a stick or something to get it to cover the styro. I assume you had the styro on a wire up in the air.

You can still see the "main stick" in the picture

I had the styro-core on that stick, when I sprayed on the foam I moved it around so that it was covered with strings that were close enough together to form a complete cloud once expanded. I simply sprayed some additional foam to areas which were to thin at the end.

[scottgirvan]

Cool. I'm gonna try to duplicate the exploding gun turret as seen in the Hoth battle. The scale I'm working in is tiny as seen here:

http://www.girvanmedia.com/atat/atst/11.jpg