Paint Experiments for Scalextric Plastic

Following my struggles with painting MDF I thought it was worth testing before I try to paint the Scalextric track borders.

I will want some grey and some black depending where on the circuit they are placed.

I tried house paint that I had in my shed.  This is exterior water based paint.

I cleaned the plastic with a tiny bit of detergent in water. When dry I applied the paint with no other preparation.

It did not go on very well and I did not have high hopes.

I prepared the other end for car spray paint.  I used Adhesion Aid first.

After a few hours I added the primer.

The following day I added the top coat.

Using very simple test techniques, my finger nail, I scratched off the paint.

There are three areas, The house paint, car spray paint with no Adhesion Aid and car spray paint, with Adhesion aid.

The results are as expected.  The car spray paint with Adhesion Aid is slightly harder to scratch off than the car paint with just primer. All three can be scratched off with a bit of effort.

The surprise is the house paint. On the smooth areas it is very easy to scrape off but on the rough top surface it takes enough effort that car tyres would not be enough.

Conclusion:
All three paint areas would survive slot car tyres. None will survive a sharp object but the car spray paint needs more effort to remove.
Car spray paint can be ready within hours. House paint needs to be left for at least a day to dry per coat and will need at least two coats.

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Update:  Once the paint was fully dry neither was flexible and both came off in sheets if the plastic was flexed.