Reshaping Cold Cast Aluminum Urethane Resin

[NewmanAssembles]

I have a Captain America replica helmet made from cold cast aluminum urethane resin that does not match my face shape very well. I'd like to reshape it, if possible. I've read you can reshape resin with a heat gun or hair dryer, but how hot does the material get? To get a custom fit, I assume I will need to wear it at some point in the reshaping. Is it safe to wear the helmet while heating it up? I'd love to hear from anyone with experience in this matter. Thanks.

 

[PoopaPapaPalps]

Depends on how thick the material is and you have to watch the heat, else it can burn the resin (creating fumes you don't want to breathe) or dry and crack. I'll just say wearing it to shape is an incredibly dumb idea. It's like holding the material you're cutting with a circular saw between your legs.

The best option is reshaping the profile of the material itself through sanding and filling to get it to fit your head.

 

[lmgill]

Urethane resin will soften with heat. Too high a heat and it will burn (like anything else). However, the heat required may be too high for contact with sensitive skin, like your face. We reshape pieces by putting them in the oven at 150 f. max. Some resins get pliable at 120f.
DO NOT SET THE OVEN HIGHER. Ovens do not get hotter, faster when you set them higher.
The heat setting is just an on/off switch, not an accelerator (gas pedal).
The problem with a heat gun, is the heat is much higher than 150, and you can't easily control how hot an area get, and what you are really trying to do is get the whole piece (or area) heated all the way through to the full thickness of the material. A heat gun will heat the surface, and when you move to another area, that surface cools down, while only a small amount of heat soaks in. So if you were incredibly patient, you could use a heat gun, but an oven is far more efficient and effective.

 

[NewmanAssembles]

Urethane resin will soften with heat. Too high a heat and it will burn (like anything else). However, the heat required may be too high for contact with sensitive skin, like your face. We reshape pieces by putting them in the oven at 150 f. max. Some resins get pliable at 120f.
DO NOT SET THE OVEN HIGHER. Ovens do not get hotter, faster when you set them higher.
The heat setting is just an on/off switch, not an accelerator (gas pedal).
The problem with a heat gun, is the heat is much higher than 150, and you can't easily control how hot an area get, and what you are really trying to do is get the whole piece (or area) heated all the way through to the full thickness of the material. A heat gun will heat the surface, and when you move to another area, that surface cools down, while only a small amount of heat soaks in. So if you were incredibly patient, you could use a heat gun, but an oven is far more efficient and effective.

Thank you for the detailed reply. Just so you know what I'm working with: Stealth Helmet Rigid 2 Pcs HQ | Etsy

And the main issue is when I wear it, the bottoms of the eye holes are so tight it feels as if the mask is trying to dig out my eyeballs like a spoon. I just need a little bit of reshaping to accommodate. A heat gun is clearly overkill for this, and would probably cause the paint to bubble. I was thinking of patiently using a hairdryer. My fear of putting it in the oven, even at such a low temperature is making the entire piece hot will distort everything. How pliable does resin get at 150 f? Are we talking it's like loose clay? Or is it still stiff but pliable?

 

[lmgill]

Thank you for the detailed reply. Just so you know what I'm working with: Stealth Helmet Rigid 2 Pcs HQ | Etsy

And the main issue is when I wear it, the bottoms of the eye holes are so tight it feels as if the mask is trying to dig out my eyeballs like a spoon. I just need a little bit of reshaping to accommodate. A heat gun is clearly overkill for this, and would probably cause the paint to bubble. I was thinking of patiently using a hairdryer. My fear of putting it in the oven, even at such a low temperature is making the entire piece hot will distort everything. How pliable does resin get at 150 f? Are we talking it's like loose clay? Or is it still stiff but pliable?

If it's already painted, you may want to keep to 100-120f. Also, if it's just the eye area, then a hair dryer may work, BUT, you have to be very patient and take your time. I'd heat it mostly from the inside. It should get a little pliable at 100-120