is there a way to make a soft object hard (e.g. soft plastic)?

some thing that you could brush on and let it harden?

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lemonie8 years ago
Resin - e.g. for glass-fibre, epoxy, varnish. L
animan1 (author)  lemonie8 years ago
would it work on plastic and if so how stiff would it get? does epoxy harden fast? is it cheap? help!
lemonie animan18 years ago
Paper is soft and flexible, like glass or carbon fibres, you can stiffen these up by impregnation with resin or glue. Plastic is different, what is it that you want to make? Epoxy can harden fast, and it can be cheap depending upon how much you need. L
ShahidulI3 years ago

hi i want to make a plastic box for my soft shell crab farm which will stay on salt water and under sun always.the color will be black.wel i read that pp is best for the box but i need too many boxes and also have to save can someone tell me what i should do? There are 2 types of scrap pp hard and soft in the recycle market.but i dont think it will perform plz tell me what i should do?should i mix something with the low quality pp scrap ? I need the box strong and soft and last long under sun on water

animan1 (author) 8 years ago
maybe i should change it to (e.g. soft plastic) ??
Gorfram animan18 years ago
Thanks - that helps a lot with the "snerk!!!" factor. :)
animan1 (author) 8 years ago
im tryin to make an airsoft mask and i want to cover fused plastic and make it hard.
Gorfram animan18 years ago
It depends on which plastic you use:

Plastic #2 (High Density Polyethylene) can be formed at the temperature of boiling water, and is as readily available as the nearest plastic milk jug. Plastic #4 (Low Density Polyethylene) is essentially the same stuff as #2, and is generally fully compatible with it. They will fuse at temps ranging from 220-265 F (105 -130 C), depending on exact plastic you're using.

If Plastics #2 and/or #4 are too heavy or not tough enough, you could try Plastic #5 (Polypropylene). You'd have to get it up to around 465 F (240 C) to form/fuse it; and I don't know of anyone who's tried it, successfully or otherwise.

And Plastic #1 (PETE) should be fusible at just below 500 F (260 C), but again I don't know of anyone who's tried it.

Don't use Plastic #3 (PVC), which emits nasty toxic fumes.

Plastic #6 (polystyrene) may or may not emit nasty fumes, but is probably too brittle for your purpose anyway (or too soft, if it's in the form of styrofoam).

Good luck with your project.
The resins used for fiberglass might be a good choice mechanically, but probably not very lightweight.
animan1 (author) 8 years ago
no i want to make it
animan1 (author) 8 years ago
could you use it on plasic?
Z1ggy8 years ago
Glue? plaster of paris. Concrete......
animan1 (author)  Z1ggy8 years ago
what type of glue?? not plaster or concrete
PVA glue watered down a bit and brushed on will give paper quite a bit of stiffness.
animan1 (author)  AndyGadget8 years ago
it would also need to be light and could not shatter if it fell
animan1 (author)  AndyGadget8 years ago
what about fused plastic???? and how hard?