I heard the vinyl in the tires from some revell kits were formulated incorrectly, and would slowly melt any plastic wheels they are mounted on.

In which kits and roughly which production runs did this problem occur?

I already mounted the tires for revell a/35 Spahpanzer Luchs. It would be a pain, if not impossible, to remove the tires because I articulated the whole steering and suspension, and force needed to remove the tires would probably destroy the suspension. Would that kit be one of those suffering this problem?

Would painting the wheels or tires solve the problem?

Place the finished model on a piece of styrofoam. If those tires gradually sink in, they WILL melt plastic.

Interesting .
I've not heard of this ,
do you know the reason ?

Keith

Yes, it does happen depending on the type of rubber used. To solve the problem, paint the wheels fully so there is no exposed plastic. Once the wheels are "sealed" in the paint, you will have no interaction between the two. I have models with rubber wheels that I did years ago that have had no issues.

It's happened with different kits from various manufacturers. A friend had an 1/35 Italeri Opel Maultier that had vinyl tires that melted the rims of the wheels. AMT has 1/48 kits of different versions of the F7F Tigercat suffering from the same problem. And there was a model, from Moebius I believe, of the Chariot from the TV show "Lost in Space" that also had a problem with the vinyl attacking the styrene in the box. I've had kits with vinyl tires that have lasted for many, many years with no ill effects. Al

I've got Revell's Luchs and Fuchs on my shelves for at least a decade and they still are solid like when I opened the box. I didn't paint them at all and they haven't generated any bad reaction with the plastic.

Olivier

Tamiya`s Humvee does it too

I have an RoG Unimog and Luchs on my shelf and I haven't had any problems.

Thank you.

To be safe I removed the kit wheels and vinyl tires and will replace them with resin ones.

I am happy to report I manage to remove the wheels with vinyl tires without damaging the scratch built movable suspension and steering.

The issue is that these flexible tires have a material included in the mix called a "plasticizer" which is what makes the vinyl flexible. There is no one plasticizer, many different ones exist. Over time this material leaches to the surface of the tire and some of them react with styrene and cause it to dissolve (not _melt_, melting happens with heat, this is "dissolving").

The real problem is that plastic formulas are not controlled in any real way. A moulder can and will vary the constituents of what he is moulding during a production run as conditions change or as one constituent or another becomes more or less available. This is why it is nearly impossible to say that one company's or kit's tires are going to be a problem. It could happen to virtually any kit using flexible materials.

Now, most companies have become more aware of the problem lately and we seem to be seeing fewer instances of this, but old kits still suffer from it fairly frequently.

A similar problem happens when old tires start to split (the Tamiya LRDG truck was famous for this) and this is when one of the constituents in the flexible tire has something volatile in it. Over time, it either evaporates or exposure to air or UV cause changes in the tire material and it shrinks or splits.

Still, not all of them suffer these problems as I have an ancient LRDG truck where the tires have enither dissolved anthing nor split and it was built in the 70s. On the other hand, I also bought resin wheels for my next LRDG build...

HTH

Paul

Thanks that info , Paul
Cheers,
Keith