U.S. plastic recycling codes - what works for props/models?

[Sluis Van Shipyards]

I can't remember if it was posted on here, but I can't find the post. What plastics are worth saving for props or models? I know a number 6 is styrene so obviously it can be glued, sanded, etc. What about the others? I found a cool part that is a 5, which is polypropylene, so can it be glued?

 

[Mr. Nagata]

Unfortunately, PP is the worst for gluing, sanding, and painting.

 

[Sluis Van Shipyards]

That's what I figured. Thanks.

 

[NormanF]

Unfortunately, PP is the worst for gluing, sanding, and painting.

But it is great for tools that you do not want anything to stick to.

 

[Darth Lars]

Unfortunately, PP is the worst for gluing, sanding, and painting.

PE (and in its variants of HDPE, LDPE, PEX) is worse than PP for gluing and painting, in my experience. But PP is a close second.

However, you could use bolts, use sticky tape/decals or fill it with resin to create a plug that has an undercut - and attach things to the plug.
You could also try a paint that envelops the part and holds itself together, like Plasti-Dip does: thick acrylic has worked on PP for me because it did so.
I have heard that flaming it can temporarily change the surface tension to allow better adhesion - this is sometimes done industrially to allow decals to stick better.

Good plastics for props:
* PET (1), plastic bottles. Works fine, but not often you find it in a useful shape.
* PVC (3)
* PMMA is acrylic.
* PC is polycarbonate. More impact-resistant than acrylic. Not suitable for laser-cutting from what I have heard.
More unusual: PC-ABS (PC and ABS blend), PBT: you find them mostly on equipment that need to be durable. PC-ABS is like ABS, PBT is very hard and can sometimes have a ceramic feel to it.

BTW. PP is the material used for drain pipes in my country, but for some reason they are often labelled "ABS pipes" - I suppose ABS is an acronym for something else than the plastic in this instance. Very confusing. I built my very first prop out of a PP tube ...
The only place locally where I have been able to find any assortment of PVC pipes and fittings for water has been a store that caters to salt-water aquarium enthusiasts. There is some use for cable ducting though. ABS plastic don't seem to be used in house construction over here.

 

[WesDoesStuff]

PP is the material used for drain pipes in my country, but for some reason they are often called "ABS pipes" - I suppose ABS is an acronym for something else than the plastic.

ABS is Acrylonitrile butadiene styrene. ABS pipes are usually black. PP is Polypropylene. They are two very different plastics. PP is resistant to acetone while ABS dissolves in and can be solvent welded with acetone.

Edit:
To add something to the thread, HDPE can be melted in your oven and molded into durable plastic forms.
See https://www.youtube.com/watch?v=xvbfLS-JgwA

 

[Sean]

ABS is Acrylonitrile butadiene styrene. ABS pipes are usually black. PP is Polypropylene. They are two very different plastics. PP is resistant to acetone while ABS dissolves in and can be solvent welded with acetone.

Edit:
To add something to the thread, HDPE can be melted in your oven and molded into durable plastic forms.
See https://www.youtube.com/watch?v=xvbfLS-JgwA

that kid is just to cool.

What if I have a bottle with just the triangle symbol?
Iv'e started a build were a small plastic bottle will play a major role In my prop.

 

[cavx]

I have glued PP but yeah, a bit hit and miss. I used superglue when it did work.