yes
Both, strangely enough. Applying the paint to the car is a physical change. The paint is a polyurethane compound. When you get it, it's in at least two containers - the paint, and a hardener. Stir them together and they undergo a chemical change.
The amount of hardener to add to paint typically depends on the specific product and manufacturer's instructions, usually ranging from 1:1 to 4:1 ratios of paint to hardener. Always refer to the technical data sheet for the specific paint you are using for precise measurements. Mixing too much hardener can affect the paint's performance, so it's crucial to follow the guidelines closely.
If you don't use hardener in paint that requires it, the paint may not cure properly, resulting in a soft, tacky finish that remains vulnerable to damage. This can lead to poor adhesion, reduced durability, and an increased risk of peeling or fading over time. Additionally, the lack of hardener can affect the paint's drying time and overall performance. Ultimately, not using a hardener can compromise the quality and longevity of the paint job.
Different paints require different amounts of hardener. If there is a label on the paint it should have the ratio on that. One part hardener to the about of paint you use will usually be enough. You can't store the paint after the hardener is in it, it will set up in the can. ----- In actuality a 1:1 mixing ratio of paint to hardener (catalyst) will usually result in brittle massively overcatalyzed paint that will flake and/or chip easily. However as previous stated different paints require different amounts of hardener, alway request a Product Data Sheet (PDS) or Technical Data Sheet (TDS) from the paint manufacturer or retrieve one from their website before mixing.
This depends on the type of paint. You will have to follow those directions. The colour coat I used recently does not use thinner. The clear coat used 25% thinner and 25% hardener.
Just paint it!
If the change in paint colour results in a change in price, or the change comes so late that paint has already been purchased, it is a Variation Order, otherwise it is an Architect's Instruction.
Paintbrushes can be used to paint your Neopet the colour which the paintbrush specifies. i.e. A paintbrush is one method which you can use to change your Neopet's colour. Paintbrushes for Petpets are also available - these change your Petpet's colour.
it causes surfaces to which applied to change colour
Doubtful.
the paint will crack a lot easier compare to the right mixture..