i want to make a mold i can pour plastic into, what do i use?

im working on recasing my palm tungsten T, and so i was wondering how exactly i should go about making the mold to cast the parts.
im thinking i'll have to make a prototype of the part with something like clay, after its been baked, of course. then what can i use to make the mold? ive seen plastic pellets you mix with water and it makes well, plastic that you can pour, and i was thinking i should use that for the final product.

but what should the mold be made of? it would need to be easy to get the part out of it, but it cant be too easy or else it might not set right.
ideas?

rickharris6 years ago
Plaster of Paris well greased
Silicone (caulk if not too big)
plasticine
Salt dough - google recipe

Anything that will maintain the shape.

Shape lock - or polymorph - the low temp plastic you speak of will go pourable if hot enough BUT - it burns, and IF you get it on your skin your heading for hospital with 3rd deg burns - because it won't come off.

Generally it is moulded by hand at around 60 - 70 deg C not as a liquid.

Most Thermo plastics will melt to the point where they can be squeezed into a mould - usually needs to be hard and enclosed as pouring isn't an easy option.

Look up Vacuum forming - it may do what you want.
zack247 (author)  rickharris6 years ago
i know about vacuum forming, but it wont yield the results i need, since i need the inside part to be shaped to cradle the screen and motherboard and battery, and the outside (the part you would see) needs to be rounded and have various misc. details on it for the jacks and stuff.

i might go to a craft store and see what they have, i could possibly use a epoxy of some sort to cast the final part (IE the part would be made of the epoxy resin) and i know that it could work but im not sure if it would stick to the mold, perhaps if i were to use a epoxy to make the final piece, i'd need to use either a silicone or plasticine mold?

i was just thinking the epoxy might work since it dries hard, plus its easily aquirable around here.
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Kiteman6 years ago
See the "related" projects to the right?

Plus, search the site for "mold making", "casting techniques" etc.