Foam and Plaster Prop Tutorial (part one)

got a lot of questions about how I make props, thus the video
Also known as "How To Use Cheap Hardware Supplies To Make Large Props (featuring: Expanding Insulating Foam)"
Part 2: • Foam and Plaster Prop ...
Updated to add, don't use the Great Stuff foam for this technique. It tends to shrink and expand a lot after being carved down (probably due to humidity). This means it won't hold its shape/surface well, and will eventually cause the plaster to crack.
written tutorial can be found here: commishenanigan...
for questions, or commissions, feel free to contact me @google.com (commishenanigans), or commishenanigan...

[@leopardqueen86]

This actually helped me a lot to make tonfas for talim from soul caliber 4.ive been trying to figure out the best way to cover the foam! Thanks.

[@mariek5633]

Thanks so much for this EXCELLENT tutorial! Very thorough with excellent video and especially good explanations!

[@commishenanigans]

Marie Knoerl You're very welcome, I'm glad you liked it!!

[@newgeneration3496]

I’m looking to make a windshield for my boat, the design up the center of ur helmet is exactly what I wanted to do. I’ll obviously need to use fiberglass after but your video certainly helped show the process

[@IssiebieBlackley]

Hey man! This honestly helped so much - I'm thinking about doing cosplay tutorials and such, but I don't even know how to do it myself. I've been looking around at different techniques, and for the foam, this is definitely the best tutorial I've seen. So yeah, thanks as this really helped me to get started :)

[@RCAdventure2.0]

Excellent! You have an great tutorial here ! Thanks

[@commishenanigans]

Thanks, glad you like it!

[@mx.mayhem28]

I started to make this today and it was looking good. Later I went to get coffee, saw it when i left, not even gone for an hour and when i came back IT WAS GONE!!! Can and everything. I had left it in my apartment garage. I had eventually found it in the trash compacter. It was fine. it was on the top with the door still open so it didn't get squished but i am still pissed about it. but I'm not digging through the trash to find the can.

[@abinari]

WHY DOES IT LOOK SO FUCKING TASTY

[@elitepotatochip8888]

Thank you bucko this will definitely help me with my Halloween project. The project is a 12ft posable grimm wendigo.

[@iamsawart5580]

Nice! You make it look so easy!

[@johnoktavec]

you're a great sculptor.glad you can see whats already there before you do it."the vision".keep on building.

[@shedevious3793]

This is genius! Always wanted to make my spartan from halo but never really knew how to go about it

[@aaronferguson7258]

You can mold spray foam. 1 thing spray foam won't stick to Vaseline. Wait for skin layer and mold

[@commishenanigans]

We did some fun molding stuff with it for work just recently using a plaster mold, though I'd like to experiment with it more. Getting the skin timing right for detail was a bit of an adventure haha

[@NoctisRaiden]

So helpful, you really deserve more subs, thanks again.

[@commishenanigans]

Noctis Raiden glad I could help!

[@roehle9962]

eyyy we've got the same knife! Herbert'z are very rare, even here in Germany.

[@commishenanigans]

Awesome, I love this knife! My dad got it from an army dude and passed it on to me, so I never knew what type it was before

[@nadronnocojr]

Can you cover it with the skin on, I ask I’m tryin to make a faberge egg and the mold I used gave me perfect shape , I just wanted to cover with plaster , so I could use enamel ... thanks for this series

[@commishenanigans]

Nice, that sounds awesome! But unfortunately I don't think so, though I'm not positive. The porousness of the carved foam is part of what helps the plaster stick so well, since it's got a ton of texture to grip to. The times when I've dripped plaster onto uncarved parts it can usually be popped off pretty easily, but it might be different if the whole thing were coated. I will say though, I know you can at least spray paint the foam directly from the mold. I did tangerines directly from molds for work, and coated it with three colors of rust-oleum without a problem. You might be able to use that as a base coat and paint your more detailed enamels on top. Flexing that causes cracking would be the only risk there, but if that's not something you need to worry about then you should be fine. If that IS something you're worried about I know there are paint brands that have an enamel-like paint that can be flexed. A clear flexible topcoat might also be a good sealant option so you can use the paints you have, but not risk them flaking off if they get cracked. Good luck with your project!

[@fredrikoregard832]

Thanks for good demonstration! 👏🙂

[@ChadKovac]

LOL at your "and now you have a curve..." ;)

[@retolop]

Marvelous Best regards From The Land Of Mesopotamia Iraq - Baghdad

[@qu33nly97]

really great tutorial!!!!! THANK YOU :D I'm trying to make a sword, a normal sized one not oversized so will it be just as sturdy?? the blade will be about an inch thick...??

[@commishenanigans]

Thank you, glad you like it!! I feel like for a sword you might want to try foamcore or foam board instead, just because thin long shapes are probably more likely to bend and crack the plaster, plus you'll have to put a lot of effort into planing it down flat. If you really want to use the foam-plaster combo though just make sure you have a good sturdy piece of cardboard for your core piece. The other option that comes to mind is EVA foam, but even though that'll be extremely sturdy it'll also be a bit wobbly since that type of foam isn't as stiff. Hope this helps and good luck with your piece!

[@deltatango6793]

You eventually take the hat out? Do you plaster the inside? Do you seal it before wearing it? I’m trying to make a foam sphere to use as the core of an ottoman. Would you suggest using a more dense foam? Is there a brand you prefer? Have you ever filled a mold with foam? I’m tempted to spray it into a deflated beach ball lol 😬🙃😅 Great video though!!! Thanks!

[@commishenanigans]

Hey there! Sorry for the delayed reply, and also glad you liked the video! Not sure if it's too late now, but to answer your questions: I pulled the hat out after the foam was fully cured and before I carved anything, since I wanted to make sure I wouldn't ruin the hat. If you plan to do that though it's important to coat the core with something, the way I used aluminum around the hat in this case, otherwise the foam will stick to whatever you spray it on. Since this was just something for me I didn't bother to plaster or seal the inside, since the aluminum foil already provided a layer between me and most of the foam. Not very pretty, but effective enough haha. To make something like an ottoman though I actually would probably suggest pink panther foamular insulating sheets like these instead www.homedepot.com/p/Owens-Corning-FOAMULAR-150-2-in-x-4-ft-x-8-ft-R-10-Scored-Squared-Edge-Rigid-Foam-Board-Insulation-Sheathing-45W/100320352. You have to glue the sheets together (preferably with a spray glue, but hot glue or something like gorilla glue technically work too), but once you do you have a nice solid block, and the foam is much more dense and sturdy. You can cut them into roughly the shape you need before gluing them together to make it easier to carve as well (like cutting it into graduated circles or squares). A hot wire cutter works great for a rough shaping job too, or most hardware stores sell long foam cutting knives as well. Spray foam tends to be a bit weaker, so I'm not sure I'd recommend it. One of the strongest brands I've found, and used here, (Kwik foam) seems to be tricky to find these days, and still tends to squish a bit if you press it. Almost all the other replacement spray foams I've used collapse somewhat after being carved, though red devil works fairly well. If you do spray it onto a beach ball that's definitely the brand to use. I would probably recommend spraying it onto an inflated one rather than into a deflated one though. I'm not sure how trying to inflate a beach ball with foam would work in general, but also I'm afraid that if you fill the beach ball enough to expand it the extra expansion as it cures might burst it haha. Hope this helps, and that the info didn't come too late. Good luck with your ottoman!

[@TescoSushi]

thanks this really helped, subscribed!!!!

[@beantomii]

I'm making a staff with this method, and I've finalized my shape. Only now do I see that I wasn't supposed to use Great Stuff, even though that's all that's available where I am. Do you think I'll be okay if I use good quality plaster? I just don't want my work to go to waste, because my parents will not be happy if it goes downhill and I have to try a third time.

[@commishenanigans]

Oh bummer! Hmm, the best I was able to do when I first discovered the problem with Great Stuff was spot-fixing problem areas. Basically what you do is coat the foam with plaster, wait for it to dry, sand it down, then fix the parts where the foam has expanded through the plaster by carving the foam down and adding more plaster in just that area. Some options to make plaster stronger are increasing the amount of plaster to water ratio or adding a little wood glue/elmer's glue when you mix it. I haven't tested those to fix Great Stuff foam expanding, so I don't know if it'll help, but those are both techniques that usually help with making plaster less likely to crack. Some other options might be using a different material to surface your foam. Acrylic-latex caulking is something I've used with foam before, and it tends to be heavier and takes a bit to build up enough to cover all the holes, but because it's flexible it probably wouldn't crack. The downside is it doesn't sand well, so it's nearly impossible to get completely smooth. If you're going for texture though that could be a great option! Another option might be Bondo, which looks like plaster in the finish work, but is much more heavy duty. It's strong enough people use it to fix cars, so the foam flexing wouldn't make it crack, but it's a lot less user friendly in that you have to mix a two-part chemical together, and because it's so hard it's very time consuming to sand. If you do end up using bondo I'd recommend doing everything in a well ventilated area and with a mask. Sorry for the delayed response, but I hope this helps, and good luck with your staff!

[@tonchito1449]

Great tutorial! How did you get it so symmetrical?

[@commishenanigans]

Mostly just lots of eyeballing and adding more on if things looked wrong haha, one of the things I really enjoy about this technique is how forgiving it is. Some general tips for symmetry though are finding the center line of your piece, and measuring distances to make sure everything matches up. Another option that might work (depending on how complex the shape is) is to make a template for just half of the shape, and then use the template for both sides. Sorry for the late reply, and good luck with your projects!

[@mixedlollies7117]

Nice and explanatory...thank you..

[@ItsDomke]

You sound like Lindsay from RT.

[@commishenanigans]

+Lookoutitsdomke hot damn, I'll take it haha

[@Odsthawk27]

Commishenanigans will expanding foam work for a vegeta saiyan armor

[@commishenanigans]

Stewart Escorcia Hey there, sorry I just saw this! It's probably too late a reply to be useful, but yeah, I think you could. People generally use EVA foam for armor, but I bet a combo of the two would work really well too

[@IlaVarma72]

Can I use it for making thermocol fountain? Hope it do not react badly with thermocol? It is safe once it is dried

[@commishenanigans]

Hi there! The plaster shouldn't react with the thermocol at all, but I don't know if it'll be durable enough to be used for a fountain. Plaster tends to be really soft (like you can scratch it with a fingernail) so it wouldn't last long. I would recommend looking into ultracal for a more durable version, or even cement. If you were talking about the spray insulation foam itself, not the plaster coating, I think the answer depends on the brand of spray foam you use. Certain propellants can melt thermocol, so I would recommend doing a test on a small piece to see if it works well. As for safety, it depends on what you plan to use it for. I wouldn't eat off of it, but it should be fine in a room with you. The spray foam is bad to breathe the fumes of when it's curing, and it can offgas when you first cut it but in my experience that stops after the first few days/week or so. Sealing it with something is definitely the safest way to interact with it in the end though. Hope this helps, and good luck with your fountain!

[@IlaVarma72]

@@commishenanigans on what material it is safe to carve lightweight fountain using spray foam. which brand is better adhesive foam. i ve tried foam but it do not seem to hold water. it seeps thru

[@commishenanigans]

@@IlaVarma72 unfortunately I don't think any spray foam will hold water after it's been carved into. The only part of it that's waterproof is the skin, so once that gets broken into water will always seep through somehow. If you only want to use foam the pink panther brand of foam sheet has a very tight cell that might work. Those come in sheets that you'd need to glue together using a spray adhesive or something like it, and carving it is much more difficult unless you have a hot wire cutter of some sort. Honestly for whatever you use though I'd recommend coating it with something to make it waterproof. If you haven't already seen it I'd recommend checking out part two of this video series where I go over coating the foam with plaster. The same principal would apply for concrete or other spackle-like substances which would be more durable than just the foam itself. Another option might be a waterproof paint, like a latex house paint. It'll probably take a ton of layers to fill in all the holes, but it might work.

[@cecib91]

Thank you very much, super useful tutorial!

[@commishenanigans]

Happy to help!

[@aliboy123]

Can I use expanding foam to line the inside of a latex costume to prevent wrinkling? I need the bicpes and shoulders filled.

[@commishenanigans]

Hmm, I think it depends on the thickness of the latex, and the type of foam you use. Generally speaking I don't think I'd really recommend it, unless the suit is more than 1/8" thick and you use kwik foam (or at least not great stuff if you can't find kwik foam). My main hesitation is that the foam might expand unevenly if the latex is too thin, which will make the muscles look odd and lumpy. I've also been doing more experimenting with different types of foam and definitely don't use Great Stuff if you decide to try it. The Great Stuff foam shrinks after initially expanding, so you'll probably get a ton of wrinkles in the skin. If you do try it though, the main thing to remember is that the foam will almost certainly be permanently stuck to your suit (depending on the texture and material of the suit), so if you don't like it you're a little stuck with it. Ideally I'd recommend testing it first, but in reality I'm guessing that's not an option... Using loose carved pieces to fill it up is another less permanent option, though the tricky part there would be anchoring it in the right spots. I've used that technique before to fill up a mannequin arm for a commission and it worked really well, but it was also completely enclosed. Otherwise, using thick batting like they have for pillows and quilts might be something to look into. I think it's what costumers usually use, and definitely it'll be more comfortable to wear haha. That might also be easier to anchor, since it'd be in larger sheets and so would only need the edges tacked in place. Good luck with your suit filling, and I hope this helps!

[@aliboy123]

@@commishenanigans thank you for the info!!! Very thorough!

[@commishenanigans]

No problem, glad I could help!

[@Sweet_N_Lo]

What do you do if you dont use it all in one go? The tube where it comes from would most likely cure am i right?

[@commishenanigans]

Yeah, it stops working after a while. The problem I've had is actually the bottle gets too clogged, but the one time I tried to make it work anyway the can exploded all over me and I ruined a bunch of stuff. If you don't want to waste it though you could maybe spray it out as a big block to carve down later?

[@family4life485]

Can you use rasps and files to thin down the foam

[@commishenanigans]

Sorry I missed this, but yes, you definitely can! I'd recommend doing a small test piece first though. Depending on the specific foam you use the rasps and files might be too harsh and tear the foam up more than you want. In that case I'd stick to coarse sandpaper

[@muchao9126]

May I ask how many bottle of spray foam did you use for this project?

[@commishenanigans]

Less that one for this helmet, and I believe about 1 for the giant club, and 2 ish for Fishbones (to help with some variable size reference). If you're doing something bulky stuffing the core with newspaper is a great way to fill space without adding weight

[@commishenanigans]

I just made some stuff with spray foam again so I wanted to re-answer this.... Turns out how many cans you need will vary really dramatically based on the type of foam you get, and since it seems like Kwik Foam isn't around anymore the numbers I gave here probably aren't very accurate.... I used a new brand of small gap filler for my last project and something a bit smaller than the helmet took a full can. On the bright side, the foam sticks well to itself too, so you can always add more as you need it!

[@WhiteLightning008]

This helped a lot thank you so much!!!

[@gigglechan15]

Just wondering: is this safe to wear for several hours? Is any of this toxic (say after being covered with fabric)?

[@commishenanigans]

As far as I know no. I wore my helmet for almost a full day (multiple times) with no ill effects. It might be worth taking the time to let the foam off-gas for a few days if you'll have a ton of it with what you're making, since the fumes might be a bit strong at first, and the carved foam is a little rough so it might get itchy if it's rubbing on your skin for a long time. Aside from that though, especially with it covered with fabric, you should be good!

[@gigglechan15]

@@commishenanigans Thank you so much for your help!! I'll be making my first fursuit ^__^ should work!

[@orginaljun]

The fumes are toxic, let it fully dry inside out, ventilate room, wear protection, full body suit, mask, gloves.

[@AsheAisling]

Love the knife that you're using! What knife did you use?

[@commishenanigans]

Thanks! I'm not actually 100% sure, since it was given to me by my dad after someone else gave it to him. Someone else in the comments said it looked like at Herbert'z from Germany though!

[@xandir8254]

hi! This was super helpful! What brand of foam did you use?

[@commishenanigans]

I use Kwik Foam, but as far as I know any brand will work. I'm not hugely fond of Great Stuff, but that might be a personal preference thing. Also sorry it took such a long time to respond, I don't know if you even still need that info haha

[@tylervanroy8027]

This is amazing

[@BigBuddha3]

Hi, Super Video! Ich hätte drei Fragen. 1. Wo kann man diesen Pu Schaum kaufen? 2. Bleibt er auch auf einer Leinwand kleben? 3. Ist es nicht gefährlich ohne Schutzmaske und Handschuhe das zu machen? Soll ja irgendwie krebserregend sein das Zeug, oder nicht? Vielen Dank!

[@DrakkarCalethiel]

Molloy 1. eigentlich in jedem Baumarkt. Frag nach Fenster/Türen Isolier Sprühschaum. Kostet um die 5-10 Euro. Gibts in Flaschen und Kartuschen. 2. Sollte eigentlich funktionieren. Der Sprühschaum haftet fast überall. 3. Nicht wirklich. Ist in den meisten Fällen harmlos. Trotzdem vorher IMMER die Dose/Kartusche lesen. Handschuhe währen nicht schlecht weil das Zeugs eben fast überall haftet. Zum verstreichen natürlich ein Muss!

[@BigBuddha3]

Wow, super, danke für die Antwort. Könntest du mir noch sagen, was du meinst mit "Zum verstreichen natürlich ein Muss?" Ich habe vor damit quasi zu malen, so verrückt das klingt. Organische Formen auf einer Leinwand herstellen die dann haften bleiben. Danke nochmal, lg

[@DrakkarCalethiel]

Molloy Versuch es mit etwas Spühlmittel und Handschuhen zum modelieren/verstreichen. Habs zwar noch nicht versucht könnte aber funktionieren.

[@DrakkarCalethiel]

Molloy das funkt auf jeden Fall. Einfach die Leinwand flach auf den Boden/Tisch legen, 30-60 min warten, > fertig

[@logicandlove8555]

wow thank you thank you 🌹

[@charcoal386]

Thank you

[@yokotheneko62]

will this work for a halo 4 dmr

[@commishenanigans]

Technically yes, but you'd have to do all the details in the plaster rather than the foam since the foam is so porous. Honestly I'd suggest trying EVA foam instead for a weapon like that. It's a closed cell foam, which means you'll be able to do all the details in it pretty easily, particularly if you have a dremmel. It's what I used for the keyblade I made commishenanigans.tumblr.com/tagged/keyblade

[@jaredhansen2521]

Very useful

[@commishenanigans]

Glad you liked it!

[@cloroxbleach8917]

this is genius.

[@commishenanigans]

Thanks!

[@LonelyAssassin96]

Speaking from past experience: expanding foam DOES NOT STICK to plastic/saran wrap. Don't know why, it just doesn't.

[@commishenanigans]

Interesting... maybe the lack of porousness? I noticed it wasn't great about sticking to aluminum either. Could be useful for making a mold though!

[@TrafalgarLawToraonakamapunx]

where did you buy the foam can?

[@commishenanigans]

+Trafalgar_Law_Torao from a local hardware store called City Mill, but I'm sure most hardware stores in general will have it (or at least something very similar)

[@TrafalgarLawToraonakamapunx]

+Commishenanigans Ah, well long similar supposed, much thanks tho!!:D

[@Ksureme]

Home Depot has all sorts of different expanding foam.

[@waxeye6488]

👏👌😀

[@leonardothefabulous3490]

NEVER cut anything on your lap! That's what work-any table is for. One slip-and you're in the hospital.

[@commishenanigans]

In an ideal world, sure, but sadly I didn't really have a work table at the time. That's what the heavy canvas work pants are for though haha. Gotta work with what you have available

[@KOAlleyCat]

It’s a fucking pocket knife and she’s cutting away from herself. I think she’ll be fine 🥴

[@leonardothefabulous3490]

The fact that you chose to be rude to and try to insult someone who’s offering safety advice demonstrates that you are a disgusting, low-life piece of sh*t. And do not bother responding-I will not read any mor eo fyour foul mouth crap.

[@tonunknown1]

Well, I done fucked up and touched it... it’s everywhere... fml

[@Moleatmyass]

I also have a pusheen shirt on while watching the video wtf hahaha

[@jeffjeronimo94]

Quick question Is it hot in there🤔

[@commishenanigans]

Surprisingly not too badly, I think because there's airflow coming up from the neck. I've worn this during a con in Hawaii in the summer and was okay, though I wasn't running around much. Anything in the low 70's and under felt completely fine. If you plan to seal the neck up/wear a turtleneck with it it would probably feel warmer though

[@justaguy328]

I just want to re-emphasize: DO NOT TOUCH THE STUFF. You have to damn near scrape your skin off once it gets on your skin. Use gloves.

[@williamchristy257]

Step one is wear gloves! This stuff is terrible. Learned the hard way😂

[@commishenanigans]

Lol so true. I've had good luck with denatured alcohol getting it off in the past, but I'm much better about wearing gloves these days so I don't have to deal with that

[@Stupidtacocatstuffgrr]

Goodness I wish I knew that it wasn't my fault that my foam was so holey. I got the wrong type of expandable foam I think!

[@commishenanigans]

I'm not really sure why, but sometimes the foam bubbles more. I had some bad luck with I think Great Stuff brand foam, but even the Kiwk Foam I usually use does it sometimes too. It might have to do with the angle you spray things at, and how much propellant is coming out? But no matter what causes it, don't worry! The spray foam is sticky enough you can just add a little bit more to the big holes and it'll be fine to carve too. It just takes a bit longer. When I was really hurrying/had run out of foam on a bigger prop I filled in most of the bubble with crumpled newspaper instead. Not the greatest fix, but definitely an option when you're going to be covering things with plaster anyway. Hope this helps!

[@Stupidtacocatstuffgrr]

Commishenanigans yeah thank you! I bought the supply's and I coated my glaive for sailor saturn. I'll have to flip it and do the other side. I got some on my hand and boy was it had to get off xD.

[@nikimariesixx14]

I thought it said foam and potato props... I dont know why.. lmao

[@shedevious3793]

This is genius! Always wanted to make my spartan from halo but never really knew how to go about it