Sculpting/mold/casting materials Question

angel_one · Joined: 27 Aug 2010 Posts: 2

hi all, I'm a newbie here, not that much of an artist so to speak - (like my clay that's about it!) anyway i'm embarking on an endeavor to create a piece of 3d wall art (kinda - well for the fish tank Smile

)

so what i want to know is - if i was to sculpt some thing in polystyrene foam, then make a mold of this with as much detail as possible kept, then make a light weight - yet strong cast of this what materials woudl i use???

if anyone could give me some suggestions and or point me int he direction of a website with info or a place to buy the materials then i would be awfully grateful! Smile

gggraph

A lot depends on the material you want to use for the final piece, and the size.

For example, at small scale (20cm) I used rubber latex - you paint it on, let it dry, then do it again until you've got enough thickness to hold together, then peel the whole thing off.

I was casting decorative rocks for Bonsai in cement, so I found I needed to support the mould. In my case, I pushed the original rock into a bucket of damp sand, then pulled it out and put the empty mould into the cavity. The casting worked alright (although the rocks looked awful in a bonsail tray...)

On a larger scale, I've coated the original object in vaseline (to act a release agent) then completely covered it in expanding filler (urethane foam). The dry foam is quite riqid and will take a significant load. I cast some meter-wide paving stones this way.

Cheers

Grant

Tango · Joined: 06 Mar 2006 Posts: 1360 Location: Melbourne

angel_one · Joined: 27 Aug 2010 Posts: 2

tango - im in qld Smile

ok fish tank is 4 foot long so the piece will be on the larger Size.

i was thinking fibreglass with epoxy (does that combo work??)

and it has to be fish safe - so no leeching chemical ect....

but i also want it to maintain a fair bit of detail - i know most people just carve out foam then coat in concrete and resin/epoxy - i dont want the concrete and i dont want the foam in my tank!

ideally i want a strong (i fear the weight of the concrete will eventually deteriorate the foam) background that looks realistic!

so my reasearch so far is leading me to - carving out of the foam, makign a mold of this foam -** not sure with what ?**, then casting it - again not 100% on that either - as i said i was thinking epoxy and fibre glass - i was thinking of painting a layer of epoxy in the mold to pick up the detail - then doing fibreglass layers after that had set to give strength to the whole thing.

would this work?