Foam Floor Mats + Resin/Bondo = Another easy scratchbuilding technique?

[CB2001]

I've posted this thread because I had an idea. And since I had it, I'm sure someone here had to have thought of it and may have attempted it. This post was originally made as a reply to a thread about a Portal gun from the games Portal and Portal 2. So, I'm interested to see if anyone has considered and tried this method and what the end results look like. So, here is the original post.

I was thinking about how I would do an Apeture Science Handheld Portal Device if I decided to do it. Unlike most of us here, I decided to think outside the box on this. The thought that popped into my head was as followed: I know there are some people who used pieces pulled from a mold, pink foam and bondo or the paper craft method for the white "shield" pieces (basically the first piece under the barrel and the second white piece that covers the back. You know, the only white pieces on the portal gun). But thanks to Indy Mogul's Sword tutorial, it got me wondering about the use of foam.

Basically, in the build tutorial for the sword, Zack used the kind of foam that is interlocking floor foam mats that you can use in the floor of your workshop, like in the example linked. Now, I know that the shapes of those particular pieces aren't really a completely curved shape, but I'm wondering this: couldn't you use such foam floor mats (about an inch thick or less) and resin (or bondo) to harden it up and/or sand it? Or would the foam mats not retain the shape because they aren't absorbent and wouldn't be able to absorb resin or stick to bondo?

I ask because I'm surprised someone hasn't attempted this above mentioned idea (I know people have used such foam for costuming purposes). I know this isn't as insane as combustible lemons, but the question is sort of like throwing science at the wall and seeing what sticks.

Let me know your thoughts about the idea above. Also, anyone who has already attempted this, let us know what the end result was like and if the method is doable.

 

[Ozymandius]

I hate to tell you this, but if you're trying to create a hard, rounded shape, that is probably one of the worst ways to do it.

Costuming foam is great for cheap armour and swords, but not really a good substrate for building a hard shell on.

Styrofoam and tin foil are even cheaper and work a lot better.

 

[CB2001]

I hate to tell you this, but if you're trying to create a hard, rounded shape, that is probably one of the worst ways to do it.

Costuming foam is great for cheap armour and swords, but not really a good substrate for building a hard shell on.

Styrofoam and tin foil are even cheaper and work a lot better.

Okay, so the foam mats wouldn't work because it wouldn't retain the shape that you bend it to and resin/bondo up. I get it. But I can't help but wonder: has anyone tried it to see what would happen and what the end result is like?

I get that Styrofoam and tin foil would be cheaper to work with, but like I said, its an idea that popped into my head, and I couldn't help but wonder if the idea I had was a valid or possible method.

 

[Fullmetalsam]

I agree with Ozymandius on this one.

My point of view is that foam is not only for creating "cheap" armor, but is used in costuming for various reasons ... one of them is the "properties" of the material. Foam is flexible and this is why it's not a good idea to resin and bondo it. Since you don't have a solid base underneath, the resin and bondo will always end up cracking.

Anyway, I just think you're trying to mix things that have totally different properties/characteristics and they just don't go well together.

 

[Ozymandius]

Okay, so the foam mats wouldn't work because it wouldn't retain the shape that you bend it to and resin/bondo up. I get it.

Uh no, apparently you didn't get it because neither of us said that.

Allow me to be a little more clear.

Yes, technically you could do that and it would work, sort of. The problem is that it's a terrible idea to start with. You would be fighting with the materials the entire way through and end up frustrated and angry with a crappy outcome to boot.

Right off the top of my head I can think of a half dozen ways to do the same thing cheaper, faster, and easier.

Let me put it another way. You have not, in your naive genius, stumbled upon a brilliant new solution to an old problem. You have simply rediscovered an old idea that that's been discounted and discarded many times over because it just plain sucks.

 

[EZBSVS]

CB2001, I actually think this could work decently. Use the bendable foam to cut out shapes that when curved form the right pieces, but I'd use fiberglass matte and resin to get them stiff. You'd have to hold it in shape till the resin set, but it'd be a quick way to get the body formed. Then sand and bondo over the resin. Of course you'd have to use a resin that wouldn't melt the foam... But I think it has some merit.

 

[CB2001]

Uh no, apparently you didn't get it because neither of us said that.

Allow me to be a little more clear.

Yes, technically you could do that and it would work, sort of. The problem is that it's a terrible idea to start with. You would be fighting with the materials the entire way through and end up frustrated and angry with a crappy outcome to boot.

Right off the top of my head I can think of a half dozen ways to do the same thing cheaper, faster, and easier.

Let me put it another way. You have not, in your naive genius, stumbled upon a brilliant new solution to an old problem. You have simply rediscovered an old idea that that's been discounted and discarded many times over because it just plain sucks.

Okay, I guess I misinterpreted your original reply. But I get it now. I try to think outside the box sometimes and I often discover that some of the ideas I've come up with someone else has already beaten me to the punch on it (which is why I ask if anyone else has had the idea and if they tried it). But with the information you've provided has proven to be a bit more educational to me than most. Yes, I haven't made any props (unless you count the custom Sonic Screwdriver for the competition a while ago and that was barely a good one at that), but I rather ask the questions to see if anyone has tried it than to not and find out about the end result than to not ask the question, attempt it and waste perfectly good materials that could have been used for something else in a something that would have failed. I'm just naturally inquisitive, I suppose.

Fullmetalsam- Actually, the fact that the foam floor mats are flexible is part of the reason why I had the thought. Yes, I know people have taken the pink styrofoam and caved it to the shapes, but I figured that since such mats are flexible, that you could cut the shapes with a template and box cutter, then use masking tape to bend it to curve and then use resin or bondo on both sides, so that after it hardened, the piece would retain its shape. But, like I said, it's always important to ask questions like this.

 

[Ozymandius]

Hey, nothing wrong with creative problem solving, and I applaud your enthusiasm and creativity.

But I did want to clarify one comment though. When I refered to your "naive genius", that wasn't meant as a slam on you and I hope you didn't take it that way. I meant 'naive' purely in the technical sense of being inexperienced with materials.

But back to the topic at hand, the reason the foam is such a bad choice is because it would be forcing a flat plane to take the shape of compound curves. It's not just the main curve that wraps around the barrel, but the tapering curves on the ends that give the piece it's egg shape.

You can see what I'm talking about with a simple piece of paper. Getting the paper to wrap around a cylinder is easy. But think about what happens when you try and get the paper to wrap around an egg. There's no way to do it without cutting and folding the paper, and even then it's not very smooth.

Now imagine trying to do all those cuts and folds with an inch thick piece of foam. By now you should be able to see why using the foam would actually be adding to the dificulty.

 

[Ozymandius]

I've posted this seperately for convenience and readability.

I get what you were trying to do with the foam. I just don't think you thought it through the entire process.

Another cheap alternative that would work along the same lines is metal mesh or metal window screen. You can shape it to all kinds of compound surfaces, and cutting and folding is relatively easy and will lay smoother.

You then cover the sculpted mesh in tin foil and lay your fiberglass on top of that. When the fiberglass has cured, you can then just pull out the mesh from underneath and you are left with clean fiberglass shell that you can then sand and refine.

We actually just used this technique for a monster build for ScyFy a few months ago. They wanted to show how a novice could fake a water monster, ala Loc Ness. So we were only allowed to use common materials found at any hardware store for cheap.

 

[CB2001]

No problem, Oz. I didn't take the "naive genius" in any wrong way. I just consider myself a bit of a thinker and, you are right, I am inexperienced with materials.

I definitely get it, basically the worst idea of attempting papercraft with a material that's thick and too flexible to retain its shape, and not to mention the sharp corners instead of smooth ones. So, its definitely avoidable when it applies to something like the Portal gun from Portal and Portal 2.

 

[CB2001]

I'm sorry for resurrecting a thread that we've already resolved, but apparently, Zack of Backyard FX has made a Portal gun, using sort of the same method I was asking about here: YouTube - ‪Cheap Portal Gun: DIY‬‏