Idea for Making Unusually Shaped Visors (EVA, etc.)

[dmango]

Hello everyone,
I don't know if anyone has thought of this, or done this, but I think it is a cool idea that i recently thought of... You may all know the Halo 3 and Reach EVA helmets, as well as security helmets and other unusually shaped visors. Well i was looking on the smooth-on website, and came across a clear casting resin. I think it's called CrystalClear. Well i figure that the visor could be made along with the helmet, separately molded and cast in this resin, and then sprayed to be reflective. I know there's a thread about custom visor making using a kind of metallic lacquer and color coats, but also, there is a spray paint that can provide the same effect when put on in thin coats. Here's a link...
http://www.dmcolor.com/products/?id=16
This was also found on another thread here on 405th.
I don't know how effective this method may be, but i figure it's worth a shot. I know I'll be trying this later. If anyone has tried this please post your work, it would be great to see. Also, I'd like to thank the creators of the threads I've mentioned, they are Redshirt and GunGryphon. Thank you both!!!!!!!!!!!!!
Here are links to their threads...
Redshirt's- http://www.405th.com/showthread.php/16910-Tutorial-Make-amp-Paint-Your-Own-See-through-Visor
GunGryphon's- http://www.405th.com/showthread.php/30025-Cheap-Visor-Tinting-Alternative?highlight=spray+paint+visor
I highly enjoyed these threads.

 

[ventrue]

I hope you took note of the "not for home use" part. The Crystal Clear series consists to about 80% of an isocyanate that is not just toxic, but actually carries the European T symbol (the T stands for toxic, the one with the skull). You don't see these very often as a consumer - that says something about how dangerous they are.

 

[Necrogenesis]

with that in mind, do you know of any substance that can be used for custom mask creation? Perhaps a thin plexi that can be manipulated with a heatgun?

 

[dmango]

Wow! That toxic! A good alternative could be using the thin plexiglass with the heat gun, or even vacu-forming (sp?) a clear plastic sheet.
This is the tech-info for the Crystal Clear casting resin...
http://www.smooth-on.com/tb/files/CRYSTAL_CLEAR_200_TB.pdf
Although it is toxic, i do have access to a fan ventilated room at my dad's cabinet shop, it's used for applying pain, lacquer, etc. i have respirators and other safety equipment, so i still may attempt using this at my own risk. I am not condoning the use of it. Use at your own risk with the required safety equipment.
Thank you ventrue for the warning and information about this!! It really helps.

 

[Dani Girl]

You do know that there is a Castable Clear Epoxy Resin that they make (you can use to make jewels and stuff, and it see through):

http://www.smooth-on.com/Castable-Epoxy-Res/c1295_1377/index.html

I use this one often. Its not toxic, easy to use.

 

[ventrue]

Wow! That toxic! A good alternative could be using the thin plexiglass with the heat gun, or even vacu-forming (sp?) a clear plastic sheet.
This is the tech-info for the Crystal Clear casting resin...
http://www.smooth-on.com/tb/files/CRYSTAL_CLEAR_200_TB.pdf
Although it is toxic, i do have access to a fan ventilated room at my dad's cabinet shop, it's used for applying pain, lacquer, etc. i have respirators and other safety equipment, so i still may attempt using this at my own risk. I am not condoning the use of it. Use at your own risk with the required safety equipment.
Thank you ventrue for the warning and information about this!! It really helps.

In my experience, Smooth-On is generally rather vague and evasive when it comes to safety recommendations. Instead of telling you what you need to know right away, they will rather fall back to terms like "proper ventilation" or "NIOSH approved", which basically tell you nothing - pretty much any respirator you use in the US will be NIOSH certified, even if it's the wrong one, and the word "proper" is completely meaningless without further explanation.
With that in mind, sentences like "[It is] for 'industrial use' only and should not be used by students, hobbyists, etc.." (quoted from here) and "CAUTION: NOT FOR HOME USE. THIS PRODUCT IS FOR INDUSTRIAL USE ONLY. [...]" get a whole other meaning. Saying something like that is like putting up a bright-red warning sign for them.

You're a free (and hopefully adult and intelligent) person of course, so you can do whatever you want to your health, but I would strongly recommend finding another solution. Smooth-On also has a clear epoxy resin, for example (Dani-Girl already linked it). According to the MSDS, it does not contain any hazardous ingredients, which would lead me to believe that "only" the usual safety precautions for working with epoxy resin are necessary. It's not harmless, but it's definitely more suitable for a hobbyist.

 

[Toacrabman]

Wow! That toxic! A good alternative could be using the thin plexiglass with the heat gun, or even vacu-forming (sp?) a clear plastic sheet.
This is the tech-info for the Crystal Clear casting resin...
http://www.smooth-on.com/tb/files/CRYSTAL_CLEAR_200_TB.pdf
Although it is toxic, i do have access to a fan ventilated room at my dad's cabinet shop, it's used for applying pain, lacquer, etc. i have respirators and other safety equipment, so i still may attempt using this at my own risk. I am not condoning the use of it. Use at your own risk with the required safety equipment.
Thank you ventrue for the warning and information about this!! It really helps.

"applying pain"? What exactly do you do in that garage, or is it a dungeon like mine?

 

[Jimmy Da Moose]

Making a vacuum former really isn't that difficult. If you already own a shop-vac, it's pretty cheap, too. It better than having to make the mold and work with toxic resins.

 

[marshon]

Whilst this sounds like a good idea, I've tried it, and it isn't.
I thought that a 'mouldable' substance such as clear casting resin would be ideal for complex shapes (like visors) but it has one HUGE downfall. Go through the data-sheets and you will find the minimum recommended section thickness for clear casting.
With no support (matting) mine recommended a section thickness not less than 6mm or 1/4", and even at this thickness the resin can be snapped quite easily just using your fingers. In short it has little structural strength, and it's brittle.

We finally managed to get it thick enough at around 8mm, by which time the visor weighed more than the helm and the distortions within the resin due to the layering we had to do were becoming very noticeable. In the end we used a welders mask and a hot air gun without a vac form table and just heated the plastic till it went floppy and sort of formed itself.

Having said all of that, the clear casting resin can be used exactly as normal resin, you can embed matting in it.
We found it was EXCELLENT for 'translucent' parts, light diffusers, cloudy lenses etc. Use matting tissue, medium matt or rough and you get good results. This is because the fibres are basically clear plastic. Once embedded in clear resin their refractive index drops to a very low number (not quite clear).
We made an internally illuminated brain for a theatre company using this method. Worked like a charm.

BTW, although the stuff is toxic and pretty noxious in it's wet state, it's perfectly inert once fully cured.

 

[Dani Girl]

Making a vacuum former really isn't that difficult. If you already own a shop-vac, it's pretty cheap, too. It better than having to make the mold and work with toxic resins.

for some of us, who can't make one, we have to look for other options. Especially having an oven that can handle sheets big enough to vaccumform. my oven is a toaster oven. Its fine for sculpy and small object (i can bake a loaf of bread, that's it) I have no space for a regular sized one.

 

[Dark Star]

Out of curiosity, does anyone know if you CAN use a heat gun to mold plexiglass?

 

[dmango]

Thank you! The clear epoxy sounds like a much better idea... less toxic, easy to use, less toxic...! Thank you, and also i didn't know it would become that heavy. Imbedding matting sounds like a good idea too...

 

[marshon]

Out of curiosity, does anyone know if you CAN use a heat gun to mold plexiglass?

Yes you can, the only issue is getting an even temperature across the piece. Localised areas (for example when fitting a visor) work well, but I've never tried it on a larger area.

 

[Dark Star]

I'm gonna have to experiment with this! What I'm considering is forming and entire sheet to a potential EVA I might build. Any tips/warnings?