Getting a Uniform Color when Mixing automotive base coat or single stage paint

Tags: Paint and Materials

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When paint is distributed from the manufacturer it has been processed and checked for color matching. Although there can be some slight differences between batches most manufacturers mix very large quantities of paint so that they can control the color tint and the amount of metallics in the paint.

However the paint that the Manufacturer distributes is normally not the same product that you will use in your final paint job.

Because every body shop supply center must be able to mix and match colors for thousands of different manufacturer specifications it is basically impossible for them to carry or order the exact color you want from a manufacturer. The exception to this is manufacturer stock colors which are sometimes produced in a set of about 50 different colors that are ready out of the can.

For the rest of us we depend on our local paint supplier to mix base colors and tints to obtain the correct color match for the vehicle we are working on.

White, Silver, Gray, Black, Yellow, Blue and Red are basic starting points and then color is added to the base product depending on need.

I have seen some very deep blue colors for Ford products that are basically all tint and no base while other lighter colors may be mostly silver or white.

Once the basic color is obtained and metallics are added the color should come very close to the original paint color.

Preparing the paint once you are ready to Paint

One of the most common things that happens in the shop to throw off color matching is improper mixing of prepared paint.

When you first open a can of paint that has been sitting for more then about a day you will see that the color does not match at all. This is because the metallics in the paint have fallen to the bottom of the can.

Proper mixing by the technician should suspend the metallics long enough for you to add reducer and hardener and then paint.

The ability for the metallics to stay suspended is due to the viscosity or thickness of the paint…

Think of it this way if you drop a marble in a glass of jello it will eventually sink .. maybe .. but if you drop that marble in a glass of ice tea its going to go right to the bottom.

Mixing should suspend the metallics in the paint long enough that they are the same proportion at the top of the can and the bottom of the can.

Hand Mixing Paint

Almost everyone hand mixes paint both in a shop and for hobbyist but it is not the best thing to do if you fail to take care.

When you get a gallon of paint and you try to mix it by hand it is almost impossible to get the metallics off the bottom of the can with a stir stick.

This is when we often try to pour out about a quart and mix the best we can inside the can and pour back the top that we poured off earlier in hopes to make it all uniform.

Unfortunately 70% of the time you are going to spill off a few ounces of tint when you do that.. and if you spill too much your color will definitely change.

For best results you need to pour an open can into a larger container with the lip of the paint can well within the container’s opening so you don’t get any spilling. You must also pour very fast so the paint does not run down the side of the can and not hold back until the can is empty.

At that point you can use a mixing cup to pour about a quart back in the paint can to use to harvest out any of the metallics on the bottomĀ  of the can.

This is not a fun process but it is important if you are color matching. I’ll tell you every one spills you just have to learn to do the least damage that you can.

Mixing with a Paint Mixer

Paint Mixers are great for preparing paint for reduction but you should never add solvent to your paint and then think you can shake it.

If you do the solvent will expand and when you open the can the lid will pop off like you stabbed the side of a spray paint can. It can be dangerous.

If you are painting high solid primers or paints on a continuing basis it is worth the investment to buy a paint shaker that can run off your air compressor. This will make sure that the solids and metallics are uniform before you begin reducing.


Does turning the can upside down help?

A lot of people including myself believe that turning your paint can upside down before you begin mixing will help get the solids or metallics off the bottom of the can however the amount of time that the can sits on its lid is important.

If you are doing an overall paint job and order all of your paint early it is not a bad idea to turn the can upside down from the time you get it. Many people now order products over the internet and although you hope that shipping will stir it heh .. honestly if you do buy your primer and paint and expect to have about 2 to 5 days between the time the paint gets there and you begin painting just turn your color paint can upside down.. it cant hurt and it often helps but it will not do all the work for you.

If you only have an hour before you get painting and the paint has been sitting on its bottom for a week then turning it upside down probably won’t help much at all. However if you are without a paint mixer it might be a good idea to shake the can by hand a few times and turn it on its lid for the few hours it takes to get to the point where you will be mixing.

If I know i have a few days before work will begin I always pre-mix all of the products I know I will be using whether it is paint or body filler.

I don’t give them a perfect mix but I try to get some of the separation under control to give myself a more uniform product when I need it.

Just try to mix the top to the bottom and the bottom to the top then set the can aside until you are ready and it will reduce the time and effort when you need to work your hardest.


Mixing in the Cup

It is important to remember that while you are working you should agitate your paint for best results. With the common use of gravity fed cups over siphon or pressure pots it only takes a few swirls in the gun when you have a moment where you stop. I do this when I have to move from a fender to a bumper or some other motion where I am not in continual spray mode.





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