Styrofoam hardening ?

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Daithi
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Styrofoam hardening ?

Post by Daithi »

Can anyone advise on how to harden styrofoam to a depth of ¼ inch by impregnation with some form of liquid plastic.
I have tried superglue but it etches the styrofoam.

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Re: Styrofoam hardening ?

Post by soundgen »

Daithi wrote:Can anyone advise on how to harden styrofoam to a depth of ¼ inch by impregnation with some form of liquid plastic.
I have tried superglue but it etches the styrofoam.

most organic solvents have an extremely deleterious effect on polystyrene causing it to dissolve and break down or as you describe etching it , I can't see how you can harden it in any way , but you could try gluing a thin cardboard or wood section to the surface using a water based glue I think this would work , or maybe a hot glue gun would stick card to it
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styro glue.JPG

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Inigo
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Re: Styrofoam hardening ?

Post by Inigo »

The hot gun will also destroy the styrofoam if applied directly...
I'd suggest using Balsa wood instead of styrofoam if what you want is a stiffer but light thick part...
Inigo

soundgen
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Re: Styrofoam hardening ?

Post by soundgen »

Inigo wrote:The hot gun will also destroy the styrofoam if applied directly...
I'd suggest using Balsa wood instead of styrofoam if what you want is a stiffer but light thick part...
What a good Idea !

Daithi
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Re: Styrofoam hardening ?

Post by Daithi »

Thanks both of you.
I already have the styrofoam all carved up and its 18"X13"X6"so its big chunk of styrofoam.
Its not so much that I want it stiffer.
Its that I want it harder so it will not absorb sound.
I'm making a horn inside a box.
I just know you guys are laughing now.

Daithi
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Re: Styrofoam hardening ?

Post by Daithi »

The plan was to fill the box with hard styrofoam in two parts like a clamshell, then carve a horn out of the middle of the clamshell, and then soak superglue or liquid acrylic into it to a depth of ¼ inch forming the horn while leaving all the rest of the styrofoam as raw styrofoam to absorb any stray sounds and/or leaks.
I know its a bit weird.

Daithi
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Re: Styrofoam hardening ?

Post by Daithi »

But what if I could use some of that white styrofoam glue? See Soundgen's picture above. What if it was immersed in a vat of that stuff and gently heated to push some air out of it. Then allowed to cool so as to draw the glue into it as it cools down.

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Re: Styrofoam hardening ?

Post by OrthoFan »

If you go to youtube and search for Hard Coat Styrofoam, you'll find a number of videos describing various procedures, such as this one:

(Double-click the video above or click this link to go to the video on YouTube.)

Maybe one of them would work.

OF

Daithi
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Re: Styrofoam hardening ?

Post by Daithi »

Up until now I have been searching in terms of impregnating the foam and getting nowhere, but I suppose a thick coating is the next best thing and certainly easier to accomplish.
Finally it has dawned on me that surfboards are made of styrofoam. Do they coat them in fiberglass I wonder and is this the route I should be going down. I have also been looking at a product called Mod Podge.
Thank you all for your help and advice. Any further comments are more than welcome.

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howardpgh
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Re: Styrofoam hardening ?

Post by howardpgh »

You can't use polyester resin and fiberglass on styrofoam as it will dissolve it. Usually you can use epoxy resin on styrofoam.

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