Painting softer plastic?

[zemjw]

Not sure the following link adds much that hasn't already been said, although soaking in vinegar is a new one 

http://theminiaturespage.com/ref/paintpfigs.html

[Argonor]

I agree with all that's been said about washing/rinsing etc.

The most important thing about soft plastics is, thin details (spears, swords, muskets/rifles, etc.) bend easily when touched - therefore, ALWAYS base such minis in a way that handling will not become a problem. I just use a white primer, and rarely have problems with chipping, as long as I handle the little buggers by the bases.

I hadn't heard the white glue solution before, but I've heard some people tell, they give the bare figures (after thoroughly rinsing) a thin overbrush of a kind of latex that the paint will stick onto and not peel off, should a mishap occur. It may have the same properties as 'soft plastic primer'.

Congrats on your choice of 1/72 manufacturer; Zvezda is one of my favourites. HäT uses harder plastic for their minis, but they don't come anywhere near Zvezda when it comes to detail and accuracy.

[Watery Graves]

Thanks everyone! The advice about washing is especially helpful, since I've rarely bothered with other plastic minis. I gave a test model a coat of black liquitex gesso and let it sit for a night--looks like it bends nicely with the plastic. I'll start painting later in the week.

One other question. These don't have much and flash and the mold lines aren't bad at all, but they don't clean up as easily as I'm used to--scraping with the back of a scalpel makes little thready bits come up, and sanding just seemed to make it worse. Any advice?

[Argonor]

One other question. These don't have much and flash and the mold lines aren't bad at all, but they don't clean up as easily as I'm used to--scraping with the back of a scalpel makes little thready bits come up, and sanding just seemed to make it worse. Any advice?

I cut them away with a very shap x-acto (scraping is, as you experienced, NOT the solution with soft plastics   ).

There is another method involving a straightened paper-clip inserted in a cork, then heated over a candle and used to 'iron' the flash (I guess, any thin metal rod can be used). I never used this solution, as I'm affraid to ruin the figures, but you might want to try it, especially to smooth out the threads and sanding damage. Be VERY careful if doing this on thin parts, as they may melt.

[zizi666]

True,

you can't sand PE (or PP)
Back in the days we had a blow molding extruder.
to get rid of the parting lines the pieces were held in a flame very shortly.
ofcourse we're talking rather solid shapes the size of a pingpong ball (up to a fist) and not needle-like swords or gun barrels, but you might try passing the figure over a tealight flame.

[Argonor]

but you might try passing the figure over a tealight flame.

I wouldn't recommend that. It takes next to nothing to melt the thingies.

[zizi666]

I wouldn't recommend that. It takes next to nothing to melt the thingies.

Yes, one would have to be very fast, not holding in the flame.
I think I still have some old airfix or revell figs laying around. might give it a try, just for the fun of it 

[Watery Graves]

I know I should just try it and see, but does ordinary plastic cement work on this kind of plastic? Was thinking I might try smoothing the lines with some extra thin solvent cement.

[zizi666]

I know I should just try it and see, but does ordinary plastic cement work on this kind of plastic? Was thinking I might try smoothing the lines with some extra thin solvent cement.

If you're referring to modelers glue, I guess not. It is manufactured to glue styrene based plastics.
soft plastics are probably PE (polyethylene).
As for the dissolving capability of that plastic, I found this on wikipedia :

Most LDPE, MDPE and HDPE grades have excellent chemical resistance and do not dissolve at room temperature because of their crystallinity. Polyethylene (other than cross-linked polyethylene) usually can be dissolved at elevated temperatures in aromatic hydrocarbons such as toluene or xylene, or in chlorinated solvents such as trichloroethane or trichlorobenzene

[warrenpeace]

There is a yahoo group dedicated to 1:72 scale plastic named DBLCHM. Many tips and techniques in the archived messages on that yahoo group regarding washing, priming, painting, and sealing soft plastic minis.

The vinegar technique mentioned above is just to get a slightly acidic solution to use with mild soap to get rid of the mold release agent on the plastic. The job doesn't require a lot of acid or soap. A small amount of vinegar in a pan of water overnight is what some soft plastic painters use.

The diluted PVA white glue used as a substitute for primer mentioned by Hammers is an old techique still used by some in spite of the modern availability of plastic primer. The flexibility is the advantage, even though the PVA doesn't actually bond to the plastic.

I want to try Rustoleum Plastic Primer, available in US hardware stores, on some soft  plastic minis. It's supposed to work better than Krylon.

Most of the painters who describe their techniques on the DBLCHM yahoo group use accrylic paints.

Sealing is where techniques seem to vary the most. Some painters of soft plastics use the same dull coat or matt varnish they would use on metal figures. Others coat with PVA glue (which dries clear). Still others use some sort of floor wax dip, often adding a little bit of brown to the floor wax, which works as a sort of combined wash and sealant. The PVA or floor wax outer coating is used for the flexibility, important with the soft plastics. I don't have any idea what works best. Maybe Hammers can describe his outer coat/sealing method for us.

[Hammers]

Maybe Hammers can describe his outer coat/sealing method for us.

Nothing special, really. I don't paint a lot of soft plastic miniatures, it is mostly terrain pieces and the odd miniature, vehicle, plant etc., which I have come across and which I think  will complement my projects. If the item is sufficiently matte and the item is not to be handled a lot I don't top coat. If I do I use the same  old matte spray coats over glossy coats as with everything else.

[WuZhuiQiu]

There is another method involving a straightened paper-clip inserted in a cork, then heated over a candle and used to 'iron' the flash (I guess, any thin metal rod can be used). I never used this solution, as I'm affraid to ruin the figures, but you might want to try it, especially to smooth out the threads and sanding damage. Be VERY careful if doing this on thin parts, as they may melt.

There is another, safer way of doing that - use an electric pyrogravure (or wood-burning) tool, which is like a low-temperature soldering iron. Just be careful not to breathe in any fumes, and be sure to work in an area where fire is not a risk.

[Argonor]

There is another, safer way of doing that - use an electric pyrogravure (or wood-burning) tool, which is like a low-temperature soldering iron. Just be careful not to breathe in any fumes, and be sure to work in an area where fire is not a risk.

Would be a nice solution if it is possible to adjust the temperature (I have no idea)?

[WuZhuiQiu]

They're at about the right temperature for melting plastic without burning it, but I suppose that you might rig something with a dimmer switch or transformer.