How to mix car paint with reducer and hardener

Written by paul miceli Google
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How to mix car paint with reducer and hardener
Refer to technical data sheets supplied with paint mixing kits to find the correct ratios. (sydeen/iStock/Getty Images)

Modern car paints include hardeners that promote faster drying times and reducers to help the material flow through the spray gun easily. The mixing process is a vitally important aspect of automotive paint refinishing work. Adding too much or too little hardener will alter recommended curing periods, and the incorrect quantity of thinner can result in runs, sags or dry patches in the paintwork.

Skill level:

Things you need

  • Paint mixing pot
  • Paint measuring stick
  • Car paint
  • Compatible hardener
  • Compatible reducer
  • Disposable stirring sticks
  • Cloth

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  1. 1

    Wipe out the paint mixing pot with a clean cloth to remove traces of dust and other foreign contaminants. Place the paint mixing pot on a flat, even surface. Stand the paint measuring stick against the inside wall so it rests in a vertical position.

  2. 2

    Stir the automotive paint thoroughly with a disposable stirring stick before mixing begins. Make sure the separate pigments mix together. Check the paint against the vehicle to make sure the colour is accurate.

  3. 3

    Refer to the technical data sheet supplied with the automotive paint to establish the correct mixing ratio. Remember that the mixing ratio is written sequentially. So figures of 2:1:1, for example, will relate to two parts of automotive paint, one part hardener and one part reducer. Check the markings on the paint measuring stick to ensure the correct ratio markings are available.

  4. 4

    Determine how much unmixed material is needed for painting. Refer to the left-hand side of the paint stirring stick to view the different volume measurements. Note that each numbered vertical marking represents one-tenth of a litre of automotive paint. Add paint up to marking number "1" on the left-hand side of the stick if 100 ml (3.4 fl oz) of unmixed paint is required. Add up to the number "2" if 200 ml (6.8 fl oz) of unmixed paint is needed. Add up to any other number that represents the correct volume of material necessary to complete the job.

  5. 5

    Take a tin of compatible hardener and look at the markings on the centre of the paint measuring stick, which represent the second part of the mixing ratio. Fill the paint mixing pot to the same number on the centre of the stick as you used when adding unmixed paint. Add to the number "1" if the paint was added to number "1" on the left-hand side; "2" if the paint was added to "2" on the left-hand side; or any other relevant number that matched your original paint quantity.

  6. 6

    Repeat the process on the right-hand side of the stick with compatible reducer, making sure the pot is filled to the same number on the paint measuring stick so it matches the number used for the unmixed paint and hardener. Allow the material to settle for a few seconds before stirring the three components together and adding the mixed product to a spray gun.

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