What works and doesn't work on plastics 1, 2, 3, and 5

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Zubie
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What works and doesn't work on plastics 1, 2, 3, and 5

Post by Zubie »

I've noticed that most packing plastic is no longer code 6 for polystyrene, but instead 1 poly ethylene, 2 high quality pe, occasionally 3 (pvc?), and quite frequently on the clear bubbles 5 for polypropylene.

Now from the talk about the plastics on the new hasbro Star Wars MF and X-wing, what are the problems to glue and paint these plastics, particularly given that we often want to work with found objects (pill bottles, packaging bubbles, etc). Will it glue to other plastic, will stuff make it disintegrate, will it kill you if welded (probably).

Thanks
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p.s. did look for previous thread but didn't find it
La maquina sobre mi escritorio es una "computadora" del latin "computare", no un "ordenador". El estado de mi escritorio afirma eso. (yo/me)
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Post by kenlilly106 »

Plastic #1 – PETE or PET (Polyethylene Terephthalate)
Thermoforms quite easily and can be used to make custom canopies, etc. The Squadron clear thermoform sheets are PETE.
Can be bonded with superglue and takes paint well

Plastic #2 – HDPE (High Density Polyethylene)
Can be welded using HDPE rod, doesn't take paint well and immune to most solvents. Not a good choice in for modeling applications.

Plastic #3 – V or PVC (Vinyl)
The rigid types bond with superglue, epoxies and some solvent cements, takes paint well but make need to be scuffed to remove the surface gloss.

Plastic #4 – LDPE (Low Density Polyethylene)
Same issues as HDPE, not a good choice.

Plastic #5 – PP (Polypropylene)
Solvent resistant, can be welded using PP rod, not paintable.
Can be glued using hot glue so it could be used for models as long as its skinned with something that can be painted.

Plastic #6 – PS (Polystyrene)

Plastic #7 – Other, Miscellaneous
Could be acrylic, nylon, polycarbonate, etc. Acrylic and polycarbonate can be used in modeling applications and are treated like styrene.

There's a 2-part adhesive made by 3M called DP8010 Structural Plastic Adhesive, it will bond the "unglueable" plastics to themselves or other materials, problem is that the smallest tube is nearly $30 and it only has a 6 month shelf life @ 40F from date of manufacture.

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Zubie
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Re: What works and doesn't work on plastics 1, 2, 3, and 5

Post by Zubie »

Given the abundance of ABS in toy applications, we should probably add to this thread how to deal with ABS as well (hec, the cheap Revell SW snap kits are ABS as well). I managed to get Cyanoacrylate to work with it, but fill was really difficult.
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Re: What works and doesn't work on plastics 1, 2, 3, and 5

Post by Kylwell »

There are a variety of bonding promoters made for glue and/or painting your usual low energy plastics like PETE, PET, HDPE. LDPE, PP. They work but are expensive & hazardous.

The flip option is to make castings of them. If one is so inclined.
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Re: What works and doesn't work on plastics 1, 2, 3, and 5

Post by seam-filler »

Zubie wrote: Fri Jul 10, 2020 9:50 am Given the abundance of ABS in toy applications, we should probably add to this thread how to deal with ABS as well (hec, the cheap Revell SW snap kits are ABS as well). I managed to get Cyanoacrylate to work with it, but fill was really difficult.
My go-to for sticking ABS is EMA's "Liquid Solvent Cement". A lot of Plastruct's range is ABS so it's ideally suited. The stuff has the advantage that it also works perfectly well with polystyrene and, indeed, will bond styrene to ABS. It is also available in huge quantities so works out to be very cost effective.

For filling ABS I use either Milliput/AVES or artists' acrylic modelling paste. There are plenty of brands of acrylic modelling paste out there, but the one I like the most is Pebéo. I've found that Humbrol Model Filler sticks to ABS, but since the darn stuff shrinks so much there seems little point in using it.
"I'd just like to say that building large smooth-skinned models should be avoided at all costs. I now see why people want to stick kit-parts all over their designs as it covers up a lot of problems." - David Sisson
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Re: What works and doesn't work on plastics 1, 2, 3, and 5

Post by jpolacchi »

I know this is a little off topic, but I have a couple multi-media kits.A combination of vinyl,metal and resin cast parts(and I have kits that are all vinyl).Superglue is mainly what is recommended for the vinyl kits,however...I have been wondering if other adhesives might be used (and/or in combination) on these kits,such as vinyl glue/adhesive for vinyl kits,5 min epoxy to get the unlike materials to adhere together like resin&vinyl,or vinyl and metal cast parts.
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Re: What works and doesn't work on plastics 1, 2, 3, and 5

Post by seam-filler »

jpolacchi wrote: Wed Jul 15, 2020 8:46 pm I know this is a little off topic, but I have a couple multi-media kits.A combination of vinyl,metal and resin cast parts(and I have kits that are all vinyl).Superglue is mainly what is recommended for the vinyl kits,however...I have been wondering if other adhesives might be used (and/or in combination) on these kits,such as vinyl glue/adhesive for vinyl kits,5 min epoxy to get the unlike materials to adhere together like resin&vinyl,or vinyl and metal cast parts.
I really, really hate CA so I use epoxy a lot for mixed media. The 5-minute stuff is what I use most, but if there's something that needs to be structurally very sound I sometimes use a slower curing epoxy. IMO, Epoxy is actually better than CA with vinyl because there is a little bit more flexibility. About the only thing I wouldn't recommend it for is expanded polystyrene, some other expanded (blown) plastics and really thin sections of vinyl - the heat generated by the curing epoxy can distort or even melt. 5-minute epoxy will get hotter than slow-cure epoxy.

As with all gluing, surfaces must be scrupulously clean and preferably unpainted. White metal parts can be pre-treated with metal blacking which etches the surface just enough to provide a better key for the glue.
"I'd just like to say that building large smooth-skinned models should be avoided at all costs. I now see why people want to stick kit-parts all over their designs as it covers up a lot of problems." - David Sisson
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