How can i give styrofoam a good strong finish?

[Meathead316]

Hi

Parts of a model im making will be carved out of styrofoam/polystyrene blocks. now this is a very easiy material to work with as its so light and easy to cut, but this will become its downfall in the long run and i want something i can coat it with to give it some rigidity and strength and also make it a better surface for painting.

any ideas?
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[division 6]

Several things you could use.
Modge Podge, PVA (Elmers white) glue. Gesso, acrylic paint.

 

[clonesix]

Polyurethane resin
Vanilacryl
epoxy

 

[SUPERprops]

Polyurethane resin
Vanilacryl
epoxy

Wouldn't you have to seal it first, that way it doesn't melt.

 

[TazMan2000]

Wouldn't you have to seal it first, that way it doesn't melt.

SUPERprops is right. Ensure it is a good coating, in fact ensure there are several. Any fracture or pinhole will result in some paints melting the foam.

TazMan2000

 

[XtcofPain]

If its for a rock like terrain or somethin you can cover it with a watery mx of plaster and it gives a great realistic stone effect when painted

 

[clonesix]

Wouldn't you have to seal it first, that way it doesn't melt.

Those are sealers. You can't use any solvent base paint, as that will melt it.

 

[Volpin]

Wouldn't you have to seal it first, that way it doesn't melt.

Only polyester resins will eat polystyrene foam. Urethane and Epoxy resins will not.

Recently I made a shield out of pink foam and coated the outside with urethane resin for rigidity and strength. Worked wonderfully and didnt eat the foam at all.

 

[SpiritedAway]

I don't have any advice to give but I want to say thank you for posting this question because I am just starting to research about making a shield and want to use Styrofoam as a base. All the advice that you have received has helped me out a lot.

Thank you again for posting this question!

 

[SpiritedAway]

Only polyester resins will eat polystyrene foam. Urethane and Epoxy resins will not.

Recently I made a shield out of pink foam and coated the outside with urethane resin for rigidity and strength. Worked wonderfully and didnt eat the foam at all.

Hi Volpin,

I am making a shield that I will most likely be sculpting the base of it out of and I was thinking of having my shield made out of paper mache or vaccuform plastic. If I use paper mache I will most likely need put on a release agent before I do the paper mache.I was wondering if you have any good suggestions on what would be a good release agent to put on the pink foam?

Thanks .

 

[hdtheater]

Only polyester resins will eat polystyrene foam. Urethane and Epoxy resins will not.

Recently I made a shield out of pink foam and coated the outside with urethane resin for rigidity and strength. Worked wonderfully and didnt eat the foam at all.

What brand did you use for this? Could you pst slink to the product? I recently did a foam project and am still looking for the right coating.

Thanks,

-Eric

 

[ShowCraft]

Only polyester resins will eat polystyrene foam. Urethane and Epoxy resins will not.

Recently I made a shield out of pink foam and coated the outside with urethane resin for rigidity and strength. Worked wonderfully and didnt eat the foam at all.

Is there a thread on the build of this shield? Curious as to how the raised grey trim around the design was done.

 

[robn1]

Coating the foam with resin or epoxy will give it a hard skin. But if it's too thin it can be poked through. If you want a tougher skin you can build up several coats of resin.

You can also put on a layer of fiberglass wet out with epoxy. This will give it a very tough skin. This is pretty much how surf boards are made.

 

[star-art]

www.HotWireFoamFactory.com is a great source of supply and info for working EPS foam. They have a number of special coatings specifically designed for this and also videos that might help.

 

[yuumi2891103]

I've always use car filler to cover these foam styrene. It is tough and easy to obtain.

When I finish shaping the foam styrene, I spray a hair spray (cheap one) all over it. So that the car filler won't harm the foam styrene.:lol

 

[actias]

Try this

StyroSpray Hard Coatings : Industrial Polymers

The product is called styro spray 1000. This is a mix specifically designed for coating foam, wood, ect. It can be purchased in spray or brush on. I think I paid $50.00 for a gallon kit. Great stuff and works wonderfully. They will even send you samples of things coated with the stuff.

Hope this helps

 

[DarkJedi1500]

Eventually I will try the urathane resin resin volpin uses, but right now i am a little cheap (relativly speaking, the whole projects cost alot).

The methond I have had work extreamly well is coat the foam in paper mache and then use resin and/or bondo to get the final surface. The mache I use is a half and half mixture of elmer's white glue and water, and news paper. This is the method I used for my portal gun (resin anf cloth followed by filler), Subject Delta's drill (2 layers of resin thickened with microbulb silica filler), and currenlty in work on my Dalek (going to try to use just bondo on the mache, after the last two projects I don't think I need the fiberglass on non-loadbearing details)

 

[whitedragond]

http://www.volpinprops.com/cassandras-nemea-shield/

I just accidentally came across the build after seeing this post a few days ago, here's the link!

 

[SSGGambit]

Would these recommendations apply to a foam paddleboard (SUP) as well? I’m looking to refinish my old board, but need something that will handle salt water well.

 

[HC Mullica]

It won't handle saltwater, but I definitely agree with Mod Podge as a cheap way to go to increase rigidity and seal your blocks. If you mix acrylic paint with it, it will help to ensure even coverage. You can spray paint over it.