I recently painted my Bronco II and ran in to a situation where I needed to mix up some paint, but the measuring cups I had didn’t have the parts ratios that I needed.
When you mix paint, the direction generally calls for parts in a ratio that looks something like 8:1:1. The parts consist of paint:hardener:reducer. You have to check the directions carefully though because some paints list it as paint:reducer:hardener. You don’t want to get these ratios mixed up.
For the point of this article, we’re going to go with a mix of paint:hardener:reducer.
The ratio of 8:1:1 means it calls for (8) parts of paint, (1) part of hardener, and (1) part of reducer.
When mixing, it’s best to get some mixing cups that have the mixing ratios printed right on the cup.
Below is a 1-Quart mixing cup that would generally be used to mix paint going in to a paint gun.
Using the 8:1:1 (8-parts paint, 1-part hardener, and 1-part reducer) as an example, we would pick a number on the 8:1:1 chart for how much paint we want to mix (in this case ‘5’), and then fill the cup up to the ‘5’ at the red line — with paint, then add activator up to the ‘5’ at the blue line —. and finally add activator (hardener) up to the ‘5’ at the black line —.
(8:1:1 Paint / Activator / Reducer)
But what if the ratio calls for 8:1:2, and your mixing cup only shows 8:1:1?
Simple. We’re talking parts. You simply add 2-parts of reducer instead of 1-part.
So in the example above, we would pick a number on the 8:1:1 chart for how much paint we want to mix (in this case ‘5’), and then fill the cup up to the ‘5’ at the red line — with paint, then add activator up to the ‘5’ at the blue line —. and finally add activator (hardener) up to the ‘6’ at the black line —. We went to ‘6’ with the reducer because we added one more part (1-part) to the final equation to get 2-parts.
(8:1:2 Paint / Activator / Reducer)
It’s crucial to the quality of your paint job that you get the right ratio of parts in your mix. Make sure you remember to use a strainer when you pour the mix in to your gun. If you’re re-using the same cup to mix your paint during the paint job and your wiping it out between coats with lacquer thinner, make sure you don’t wipe any on the outside of the cup. It will wipe the ratio charts right off of the cup.