Once a piece of metal is prepared for primer, it should be primed within one hour or less from the time it is totally dry. Any longer and rust begins to form and will effect the paint job over time.

Priming steps;

1. Read the directions on the can. This cannot be stated enough. Follow the manufacturers directions explicitly. Whether you are using spray can or paint cans for mixing and spraying in your own HVLP gun, follow the directions. They are indispensable. I use spray cans so the following information applies specifically to spray can, but can be applied to spray guns equally well. Make sure to note the recommended spray distance, re-coat times (normally within two hours and after 48 hours, and dry times (handling). Do not deviate from the recommendations.

2. The surface should be sanded smooth to 320 grit sandpaper and cleaned with a metal prep product or acetone. The cleaner and smoother your primed surface, the smoother your paint layers will be. No exceptions. Good prep work equals good finish results. Spend the time to get the surface as perfect as you can so you achieve the best paint results, especially on the hood, seat, wheels, belt and engine covers, and anything else on your tractor that is a natural focal point when looking at your machine from any angle. I normally block-sand the primer to 400 or 600 grit depending on the part. This gives your paint a good flat surface to stick to and insures all surface residues are removed. Clean thoroughly with Simple Green solution and dry thoroughly before applying color paint.

3. Shake the can until you hear the rattle ball clearly, then continue to shake for an additional 3-5 minutes.The additional mixing time insures all of the paint solids are thoroughly mixed with the solvents. Insure the nozzle is completely clean of paint build-up before continuing. Holding the can upright, spray one shot into the air away from your work area, to clear the nozzle and internal straw of any paint in them which may have separated during storage.

4. Begin spraying off the part and move over the part at the prescribed distance and at a constant speed. Do not stop spraying until you are off the part on the opposite side. Apply light misting coat over the edges of the part. Put a single light misting coat over all corners, rolls, creases, etc. and all "hard edges". Each  should have a single, almost see through, coating to insure a little added paint thickness in these areas. Also pre-paint any high wear areas in the same manner, very light and see through. Now put the can down and walk away for 3-5 minutes.  This allows the paint to "flash" (or out-gas, propellants and solvents begin to evaporate) and "flow" (flow and leveling of the applied paint). When you return after 3-5 minutes the paint will have released its solvents and has started to get tacky.

NOTES:

a. The recommended distance (away from the surface to be painted) is dictated by the design of the nozzle on the can. Too close, too much paint. Too far away, not enough paint. Follow the suggested distances to the letter.

b. The speed at which you move the can dictates how much paint is applied. Slow-more, fast-less. When doing a "light, misting coat" you should be moving at a rate of approximately 1 foot per second. So if you're painting a 3 foot long hood, you should be able to slowly say "1-2-3 " on each pass, and just be off the part when you finish saying three.

c. Do not attempt to "touch up" areas you did not cover well on the first pass. Get the technique down right and overlap your passes. Don't try to correct for poor technique. You only put on one coat at a time, right or wrong, DO NOT GO BACK OVER IT. Continue until the part is coated and fix any mistakes on the next coat (after 3-5 minutes of course).

5. Again, begin spraying off the part, and in a constant speed and distance manner, spray a single almost see through coat of paint over the entire surface one pass at a time. Stop spraying on each pass when you have gone off the other end of the part. Overlap each pass by 50% on top of the previous pass and every successive pass. When you are done with a single, light coat you should still be able to see primer through the paint. Now put the can down once again, and walk away for 3-5 minutes to allow out-gassing and flow out.

6. Repeat step 5 again in exactly the same manner as before. You should now see the paint going on and glossing almost immediately. Continue to overlap and complete the surface. Can down, and again walk away for 3-5 minutes.

7. Once the primer has sufficiently dried (read the can) then it can be sanded to 320 grit and cleaned in preparation for paint. Any small pits or holes in the primer can be filled with automotive glazing putty and block sanded smooth. Clean the primed surface thoroughly and allow it to completely dry (at least 24 hours) before paint application.