LESSON 1 - One Part VS Two Part Primer
One of the first lessons I learned was that no primer is created equal. There are what I like to refer to as two lines of primer, amateur (one part) and professional (two part) types of product.
The first one is the stuff in a spray can we are all familiar with. This is the stuff you can buy at you local Auto Zone parts store or at Walmart. This product is pre mixed and ready to go. Just shake the can, press the button and apply. This sounds wonderful, however I learned sacrifices had to be made to make this happen, (read the Two Part paragraph below to see how). I am not knocking this type of product I am just trying to point out the differences.
The second type of primer is what the pros use. This product is made up of two and sometimes three separate solutions that you mix. For example you take what's in the first container ie primer, and you add to it something called a "hardener" from the second container. (Different manufacturers may refer to their second product by different names, ie "activator".) The ratios differ as well, it could be a 2:1 ratio it could be something else, the instructions tell you how to mix it. The third solution may be optional, and it is called the "reducer" it basically thins out your concoction making it easier to come out of the spray gun. Once the primer hits the car, the "reducer's" job is done, it begins to evaporate. When you mix the two solutions you have to wait, allowing them time to react, this is called "induction time" it's like adding sugar to your coffee, you need to allow it time to dissolve. But unlike sugar in coffee which dissolves in seconds, this concoction may take minutes, 15 or more, etc. Ok so now you waited the 15 minutes, now you enter the "pot life" phase. This is the time you have to spray your car before your primer is no longer any good. Going back to our coffee example, this is how long you have to drink it before it gets cold. But unlike coffee which you can pop back into the microwave and warm it up again, your primer mixture is wasted.
Ok, so now you see why we can't buy the two part "good stuff" at Walmart. It's because it would be hard as a rock or coagulated like rubber, since it would have been days, weeks, even months since it was pre mixed for us at the factory. Now there are some manufacturers out there making two part primer in an aerosol can, but they have you pull some kind of a rip cord to get the solutions to mix before spraying, so technically although they are in the same can there is still some sort of barrier between them. Although I have never used their product, I think it is cost prohibitive to do an entire car with. You could also possibly ask your local professional car paint supplier to pre mix some two part primer for you and shove it in an aerosol can, hoping that by the time you drive home you can shoot it that day, I think.
Now this does sound a bit intimidating, but it is so easy even a cave man could do it, and believe me, no one hated chemistry in high school more than me.
I ended up using a Two Part Epoxy primer that you need to mix.