When Simple Green doesn't work on plastic figures, what are my options?

[Condottiere]

Back in February, acquired a lot of 30 classic multi-part plastic Chaos Warriors on eBay and have left these in a jar of full strength Simple Green for over a month...

The seller couldn't be of help, as he was merely passing on figures that came with a lot he had acquired himself...

I identified 3 types of adhesive:

Liquid plastic cement, superglue and something thick gel like. Not a problem, as I was going to hack these half and improperly assembled figures, but my issue's with the paint...

Some type of sprayed on black primer, as I didn't notice any obscured details, and it won't budge even when using a Dremel 4000 nylon brush at 15000/min. The bits that came off are on the edges, where paint would normally flake, revealing mold lines - none of the figures were clean up before assembly. The Simple Green did remove the paint on top of the primer, so does this mean that it's not an acrylic based product? In the same jar were figures from 1998 and new stuff purchased a few weeks ago, like a heavily gloss varnished sculpt and the paint came off with minimal effort, after a 2 or 3 day soaking.

Since I had planned on converting these figures, would there be an issue adhering greenstuff on the primed parts? Will have to use the Dremel's sanding accessories to remove stubborn super glue and primed parts, creating a clean surface for polystyrene cement. I have difficulty seeing details on black coated figures, so if I were to re-prime these with brown or gray brush on gesso, what are the chances of details being obscured?

Since these are plastic figures, I can't use Pine Sol and something stronger, lest I damage the sculpts...

Is there a a safe option?   

[Major_Gilbear]

Two things to be aware of: primer solvent, and plastic density.

The first means that in the case of high-solvent primers (normally automotive primers), these acheive a good bond with plastic because they just about melt themselves to the surface of the model. Of course, the high solvent content of these sprays is what makes them so good, but it leads me onto the second point...

The plastic density on old plastic GW figures is pretty good. However, from around 1995 up to about 2010, during GWs big transition to mostly-plastic products, the plastic they used seemed softer than their previous stuff was. This is because it was less dense, and that in turn means it is more affected by strong solvents in spray primers, and by solvent glues, and by strong "plastic-safe" strippers. Models of this era that were primed with spray primer are therefore often etched more deeply by them than older or more modern plastics are.

The good news is that this is mostly just discolouration, and some surface roughness, that's left on the plastic after stripping. After brushing them with your Dremel, I imagine they are pretty smooth now, so it's really only the discolouration that's left as evidence that they've been stripped. As long as the areas to be glued are scraped or sanded a little first, I don't think you will have any problems at all with glue bonds. And as long as you prime them with a good automotive primer again, I don't think you will notice much/any loss of detail on them.