I think I need a chemistry lesson here. I experienced strange cracks in the tires on the MiniArt BA-64B kit, one even crumbled into several pieces. The tires are the same styrene as the rest of the kit. I masked their inside surface, primed them with AK primer, and painted them in Vallejo acrylic. I then assembled them to similarly prepared wheels with Tamiya extra thin. once assembled to the painted vehicle the whole kit got a coat of Future and several Mig washes. Then a coat of Dullcoat (spray Can). Everything was fine until two coats of Mig filters. Large cracks appeared in 3 of the 4 tires and one had several cracks and crumbled. The tires fit snugly on the wheels, but were not under tension. I was able to salvage then with CA and liberal use of pigments. Any ideas out there? I have used a similar sequence of products many times without incident.

I would guess the white spirit in the wash attacked them

Can the white spirit penetrate multiple layers of acrylic? How else could I protect the plastic and avoid this in the future?

perhaps the paint layers were not as uniform as you believed, but more likely it got at the rubber where the tyre meets the wheel as I suspect there is no paint protecting that area and a wash is going to collect at that point aiding penetration.

Can someone clarify, are the tires styrene or rubber?


Cheers,
Joe

I just took a look at the model breakdown and the tyres are solid plastic with separate hubs; however I stick with my initial thought which is the bare plastic of the tyre where it comes into contact with the hub of the wheel has been attacked by the solvent of the wash or some other product that has been used.

Very possible, I did mask the contact surfaces of the tires and wheels so they would assemble with styrene cement. Next time I will prime the surfaces and assemble with CA instead.

I have had the same problems , not with wheels but with tracks , everything is fine until I gave them an AK/Mig wash then they started coming apart .this was a dragon Hertzer , no not the magic tracks .

It's the vinyl of the tracks and wheels. The wheels and tracks of the newer kits seem to be even more sensitive to anything that is not acrylic based. It's weird on the "old" kits this does not happen as much. It could have been a mixture of the glue used to attach the tracks and the solvents on the washes............Next time try and use a base coat of an acrylic primer and see what happens.