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Katsumiyo
07-03-2008, 09:52 PM
Pictures will be coming soon. ^^;

Porous styrofoam is a really overlooked substance that can be used for tons of stuff, particularly large objects that need to be lightweight. I used it for my Maya necklace and hair ornaments (http://www.cosplay.com/photo/1579972/), ball on Horo's sash (http://www.cosplay.com/photo/2334652/), and, most notably, my Adiane tail (http://www.cosplay.com/photo/1560032/).
Working with porous styrofoam can be a time-consuming project. However, it's widely available in many different shapes and sizes--spheres, boards, discs, cones, cubes, and even cylinders or halo shapes. You can find them online, at your local craft store, or at Michael's.

Pros:
-lightweight
-can be carved using even a butter knife
-durable

Cons:
-needs at least 2 weeks for absolute completion
-can be fairly heavy for larger projects
-can get a little messy P:

What you'll need:
-styrofoam bases
-regular, NOT SERRATED knife (only if you're carving)
-acrylic gesso
-cheap paint brushes
-sanding sponges
-paint (spraypaint is recommended)
-liquid epoxy, if you're attaching pieces

Recommended additions:
-spray-on clearcoat
-spray-on primer
-rubber gloves
-smock/cover shirt

If you see special styrofoam-smoothing paint in the craft store, do not buy it! This stuff is more expensive than it's worth, it does not apply smoothly, and it's unsandable.

If you're carving:
Take the styrofoam object in your hand, and, using your knife, cut through towards your fingers or thumb and carve the object into the shape you desire. If you're using a butter knife, which I'd recommend you do, you don't need to worry about cutting yourself this way. Once it's carved to the shape you'd like, sweep up and throw away the shaved-away pieces. :3

If you're attaching pieces together:
Use liquid epoxy to attach pieces together. Do NOT use superglue or crazy glue; it won't hold during sanding. Hot glue will melt the styrofoam. You can also use your leftover epoxy to fill in major dents, nicks, or gaps in the styrofoam.

If you need to make holes in your styrofoam:
Use wooden skewers or another long, very narrow object to poke a hole through the middle (or necessary area) of the object. While coating your styrofoam later, poke a skewer back through the hole now and then to makre sure the hole stays unclogged.

Now...we can finally really get started!
Set up your work area. I suggest using newspaper to paint over and set objects down on. If you have spheres, you can use rocks to keep them from rolling away while they dry. While painting, you can suspend smaller objects on the skewers if you want to paint both ends at once without having the gesso stick to the newspaper.

Take one object in hand at a time and get painting. Be sure you stir the gesso well before starting. Just coat one side at a time, use extra gesso to fill in little holes or gaps that appear. Be sure you set down the styrofoam to dry so the freshly coated surface isn't touching the ground or newspaper; it's a pain to peel off. You can use the skewers later to paint around each side without covering the hole you punctured, if holes were necessary.
In warmer weather, you can paint as much as 3 or 4 times a day. This is good if you're working with a close deadline. Gesso will take much longer to dry in cold weather, and may not dry at all in extreme humidity (read: rain).

Use your sanding sponges after 3-4 coats have been painted on. Keep sanding until the surface is smooth or you have sanded to the point where you can see the styrofoam. I suggest beginning with 80 grit, then moving down to 60 grit for rougher spots. 100 is good for getting rid of streaks your brush may leave.

After the styrofoam is as smooth as you can get it, layer on more gesso. This is why you will need at least 2 weeks, possibly more for this project. Each object will take 7-10 coats at minimum and sandings between every 2-3 layers.

When the styrofoam is smooth, if you'd like to you can spray on some primer. Gesso acts as a sort of primer, so you don't NEED to do this step, and whether you do or not will not have an effect on how the color appears once painted. This step is good if you're pressed for time and couldn't sand the styrofoam as well as you'd have liked to.

Paint your styrofoam! Augh, finally. If you're using acrylic paint, use a GOOD acrylic paint brush and paint on 2-3 layers. If you're using spray paint, use 2-4 light coats. Be sure to not leave any gaps or missed spots where the white of the gesso will show through.

Clearcoat. Depending on the spray paint you used, it may not require this step. However, if your styrofoam will be rubbing against anything, or ESPECIALLY if you're using an arts/graffiti-purpose spray paint brand such as Montana, you'll want to clearcoat, or else it could begin to flake off during wear. If you choose to clearcoat, be sure to choose appropriately: matte clearcoat will not be very shiny or reflective, but glossy clear coats will give a much more shiny appearance.

Are you stringing your styrofoam on something? If so, try this: tape one end of your string to a skewer or something even narrower, and push the skewer/other object through the hole to bring the end of the string to the other side. Then, remove the string from the skewer, and pull the skewer back through the first side. Now your object should have string going through one end and emerging out the other. :3
I used deep sea fishing line for my Adiane tail, so that's why it can hang and curve as I'd like it to. :3
For Maya, I used this same method and won 2nd place because of it. ^^; So I thought I should share.

If you have any questions, feel free to comment and I'll do my best to reply promptly. I may have left something out, and I'd like to add pictures and more details as well, so I'll be returning to edit this post now and then.

Ita istar
07-05-2008, 12:11 AM
awesome post! This method is a great one~~~ Keep it up :3

Mittenkitten
07-05-2008, 05:42 AM
I use polystyrene a lot when making props, which is a bit like styrofoam in its properties, and I have to add in some things that I've discovered.

When painting polystyrene, only use paints that are water-based. Alcohol based paints can crumple and melt your polystyrene.

If you're attaching things together, then a hot glue gun is an excellent thing to get your hands on. I've found that it's really durable and works wonders. :3

Aaaaand one more thing. ^^'

Another great thing for working with polystyrene (although the sheets I've been working with are from a specialty polystyrene supplier) is a hot wire cutter. Basically, a hot wire cutter is a device that heats up a thin strand of wire to a heat where it ploughs through the polystyrene effortlessly and it makes your life so much easier when cutting and shaping.

I guess the best example of something that I've made using these techniques is my Demyx sitar, if anyone's interested.

!*Jessi-Chan*!
07-05-2008, 10:44 AM
thanks for writing this katsumiyo! i cant wait to get to use this method :)

Katsumiyo
07-09-2008, 08:29 PM
-snip-
Thing is, that's what the gesso's for--not only does it make it stronger, you can paint it with pretty much whatever you wish.
And a hot wire cutter might melt the styrofoam...that, and not many people actually have a hot-wire cutter. ^^;
Also, hot glue won't hold with my method; hot glue isn't strong enough, nor can you sand it as well as epoxy. Thanks, though.

Thank you, Ita!
And you're welcome, Jessi! Don't forget to show pictures in the GL thread~

Netto_Zero
07-09-2008, 10:53 PM
A quicker alternative to the gesso is wood filler, i covered a styrofoam ball in it to make my friend's haro and you can get it really smooth, it takes about 2 layers but it's really hard, easily sandable but i put in a layer or two of gesso just as a good primer. The only problem is it's a little more pricey than gesso but not too bad.

DDR Faery Spice
08-23-2008, 03:43 AM
You are fantastic for posting this. Some of what you said we've learned from trial and error a la Rebellion and Red Queen, but it's nice to know that gesso is a viable alternative instead of paper mache! (Why didn't I remember gesso from art class? WHY?)

Thanks!

!*Jessi-Chan*!
08-23-2008, 12:09 PM
I was wondering where different size styrofoam balls can be found? It seems that at the art stores around here i can only find the small size...Maybe online somewhere?

KillaBeeSwarm
08-23-2008, 01:51 PM
JoAnn's also has them in several sizes (http://www.joann.com/joann/catalog.jsp?CATID=cat2898&PRODID=prd3399). Looks like they go up to 6 inches in diameter.

!*Jessi-Chan*!
08-23-2008, 02:07 PM
ah, thanks killa. I dont have a JoAnns anywhere NEAR me (closest one is like 2 1/2 hrs away) so i wouldnt have known that. But maybe i'll order them from there or take a field trip to a JoAnns

Ashleythedragon
08-25-2008, 12:02 AM
ah, thanks killa. I dont have a JoAnns anywhere NEAR me (closest one is like 2 1/2 hrs away) so i wouldnt have known that. But maybe i'll order them from there or take a field trip to a JoAnns

They have them at Michaels (http://www.michaels.com/art/online/home) as well.
Most craft stores should have them since Styrofoam is often used in flower arranging, and many other miscellaneous projects.

Also Katsumiyo, I Notice that you didn't mention Styrofoam Cutters (http://www.thecraftplace.com/store/moreinfo.cfm?Product_ID=327) ( Sold at Michaels, for around twenty bucks. ). Is there any reason you didnít talk about them? I find that they cut through Styrofoam really well.

Thanks for the tutorial it's a big help.

benihime
08-25-2008, 12:51 AM
i was needing some small ones and i couldn't find any gems but i was wondering what to do so that the holes wouldn't show, thanks so much!!

FyreGothChylde
08-25-2008, 01:07 AM
Thanks so much! I've been wondering how to properly make use of porous foam..This will definitely be useful for future cosplay stuffs. ^.^

Katsumiyo
09-26-2008, 05:31 PM
So sorry for the necrobump, I forgot to answer some questions and I feel terrible. xD;
Netto: Thanks for the info!
Ashley: Personally, I'm an enormous 'tard with cutters like those, so I prefer doing it by hand. This tutorial was really just how I did it. But if you, or anyone else, have good control over those, go for it!
Jessi, Killabee: Styrofoam balls can easily be up to 10 inches in diameter, they're mostly at Michael's but I found mine at a small, local craft store.
Everyone else: Thanks so much! So glad I could help. :3

nyokun
09-26-2008, 09:39 PM
Hrmm, I wonder if that is also useable with that absorbent live flower arranging foam, the kind that you can mold with you bare hands...or would it be too fragile?

Katsumiyo
09-29-2008, 09:07 PM
Hrmm, I wonder if that is also useable with that absorbent live flower arranging foam, the kind that you can mold with you bare hands...or would it be too fragile?
Never tried it. ^^; If you give it a shot, I'd be happy for you to report back here with how it turns out. ^^

Lorryl
12-10-2008, 02:27 PM
This so so helpful to me. I'm making a double-ended lance out of sytrofoam cones and balls and was really unsure of the process to coat, sand and paint it.

My only question is, I know they sell those products for bonding styrofoam to sytrofoam without the adhesive eating away at the styrofoam. Have you ever tried these things, or would you just recommend the liquid epoxy?

yuki_cross
02-04-2009, 01:43 PM
If I use this method how exactly could I attach the finished project to a costume? For example if I made faux jems and wanted to attach them to the front of my shirt?

Katsumiyo
02-13-2009, 01:39 PM
Gah!! I'm hope I'm not too late to answer questions! >< Sorry, I'm having a hard time keeping tabs on this thread.
Lorryl: No, I haven't tried using that stuff. But if it's anything like the "specialty" stuff I bought to fill in styrofoam, it's probably crap. I'm not sure how well that stuff would work, but I doubt it would sand as well as gesso.
Yuki: Depends on the size and weight of the gem. Larger things that are, say, the size of your fist, will need to either be threaded through to be supported (for which a hole needs to be made before you start working, though it's not impossible to pierce one through now) or you'll have to use epoxy. For smaller stuff, normal thread or hot glue should work just fine. If you use matching thread, it's like sewing a button: pierce one or two small holes through the styrofoam object, then thread it through the fabric and the holes several times.
I hope I answered you guys' questions!

Fancy Feet
04-23-2009, 07:29 PM
Thank you for posting this! I think I can finally get a prop made I've been struggling with for a while now. ><;
My only question is, what sort of paint would work best for a detailed project with this method? My previous experience with acrylic paint is it chips like crazy so I'm reluctant to use it again.

my2wings
04-24-2009, 12:57 AM
*bookmarks

VARGAS~
05-09-2009, 09:33 PM
So I was thinking of helping my friend make Lal Mirch's obnoxious gorilla armor plate out of foam, and I was actually thinking of using a Styrofoam wig form as my starting point, as it already has (kind of?) the same type of face-ish form to it. I'd have to add and subtract a lot though...hm...

Anyway, I noticed that there are two types of foam that stores sell in the same shapes. The rough, sandpaper-y feeling kind, and the smoother kind (that the wig form is made of). Is there any particular kind we're talking about here?

KakeraのTsuki
05-10-2009, 10:27 AM
Useful! =]

To add to the info: Instead of gesso, I use spray-on polyurethane. It doesn't eat away at foam and seals it enough to spray-paint without any trouble. It's a good alternative for people who are on a time limit, since you can finish it in two days if there's nice weather.

Three coats is plenty, from my experience, but because the spray is clear you'd have to be extra careful keeping track of where you've sprayed. There's a slight difference in texture, so you can tell that way.

Of course, it's more expensive than gesso, but not by much.

Ani_BEE
06-08-2009, 07:22 PM
I stumbled on to this but to add to other coating methodes.

White glue/wood glue and paper, it's another for form of paper mache as a a top coat. the other option is Paperclay. it's what my Timcanpyi is made of with a foam ball centre.

Tim's body (http://www.cosplay.com/photo/1668821/)

Sugarlat
07-06-2009, 12:09 AM
Will liquid epoxy be able to attach the Styrofoam to wood as well?

Kell-chan
07-07-2009, 12:20 PM
Based on my own experiences with epoxy, it SHOULD be able to bond foam to wood, but DO NOT get the "fast-drying" stuff. It gave me so much trouble that I feared and hated epoxy for a while. Gorilla brand wood glue will also work. That stuff is godly. :)

Sugarlat
07-07-2009, 03:30 PM
So I should get the Gorilla brand to stick it to the wood but if I want styrofoam on styrofoam i should get the epoxy?

xylan
07-08-2009, 05:47 PM
So I should get the Gorilla brand to stick it to the wood but if I want styrofoam on styrofoam i should get the epoxy?

I have personally attached styrofoam to styrofoam using gorilla glue and it works. That glue is just amazing.

Archangelz
07-22-2009, 11:30 PM
Hi there!

My housemate has been following your suggestions for this sort of work for a while now and I thought I would chime in. I'm making the fork for the Wonder Chef and it's coming along nicely as a work of Styrofoam and Gesso. I'm at the first sanding stage now and it seems like I will have to do it for over a week to even get the biggest bumps out of my prop, not to mention the little ones on the edges needing even more work. Is there a faster way to do it? Or is this really just one of those things that is going to make my arm hurt day after day?

Yo-Yo
07-23-2009, 12:56 PM
I need to ask, as I'm making Adiane, too..

How much did your styrofoam balls cost? I went to Michael's and they cost $20 each! Wal-Mart had more beat-up ones for $15 D8

Sugarlat
07-23-2009, 06:23 PM
I see them at Jo anns for like 5 for 3 small ones I think
I don't know how your finding them so expensive
I bought a long 4ft thin styrofoam board for like 5 bucks each though.

Katsumiyo
12-30-2009, 02:20 AM
That's it. I'm subscribing to my own thread so I stop missing responses! Fail, Katsu!
Sugarlat: I live in a very small town and the nearest Michael's or JoAnn is literally 45 minutes away.

For those of you (that would be most) that are having sanding issues, I heartily recommend using a mouse sander, especially if you're sanding flat surfaces. Don't use anything heavier, though, or you may crack the layers and have to use spot putty or more layers of gesso to cover it.
I haven't used this method too many times, so I don't know what else will cover it or melt it. Apparently, things like wood putty or a butt-ton of epoxy may work. You can also cover them in paperclay, but this will make them bigger, more likely to crack, and probably heavier. It is, however, faster.

Celyddon
01-18-2010, 12:44 PM
I have a quick question for you. I've already carved a longbow blank out of my blocks of porous styrofoam (the gift of a neighbor who works in packing plant), and it's currently tillering (being bent to train a curved shape into the foam).

Does Gesso make the foam stiff? I need to know if I should paper mache over the first couple layers of Gesso to keep the curvature before the final smoothing layers (i.e. put 2 layers of Gesso on foam; paper mache 2-3 layers, final 2 coats of Gesso + sanding as primer for acrylic paint) or if Gesso will make it somewhat stiff enough to hold a curve without paper mache. I know that Mod Podge will hold foam to a curve, but it remains too flexible for what I'm needing.

SapphireChaos
01-24-2010, 03:59 PM
Thanks for this tutorial, I am usuing it as we speak ^_^ lol. I hope it works well!

Katsumiyo
01-27-2010, 03:02 AM
I have a quick question for you. I've already carved a longbow blank out of my blocks of porous styrofoam (the gift of a neighbor who works in packing plant), and it's currently tillering (being bent to train a curved shape into the foam).
Does Gesso make the foam stiff? I need to know if I should paper mache over the first couple layers of Gesso to keep the curvature before the final smoothing layers (i.e. put 2 layers of Gesso on foam; paper mache 2-3 layers, final 2 coats of Gesso + sanding as primer for acrylic paint) or if Gesso will make it somewhat stiff enough to hold a curve without paper mache. I know that Mod Podge will hold foam to a curve, but it remains too flexible for what I'm needing.
A longbow, huh? Personally I would paper-mache it first, yes, and then gesso it. Gesso will keep it stiff, but paper mache would help give a project that large some extra strength.