Hi Frank,
I love your question! I've been "tole" painting for 25+ years. It is very important to "dress" your wood before you paint it.
Here's my technique. I like to pre-sand my blanks before I cut them out; graduating up to 180 grit sandpaper before I scrollsaw. After scrolling my project, I sand off all burrs and spot sand any rough areas/edges. I wipe off my project with tack cloth to remove all dust left from the sanding process. You can also use an air compressor, but I can still find lingering dust. I prefer using tack cloth.
Once my project is free of dust, I apply a coat of wood sealer (you can find an all purpose wood sealer/finisher in any craft store). Paint on sealer is better than spray on sealer; better coverage, less waste. Once the sealer dries (usually 10 minutes), I lightly sand with 600 grit sand paper (it smooths out the finish - you can feel the difference). Usually one coat of sealer does the trick. If I'm painting on pine wood, I might apply a second coat. Pine likes to bleed sap. A second coat stops any bleed out long term.
Once the sealer is completely dried and lightly sanded, that's when I would draw the pattern onto the wood so I can see what and where to paint. You can freehand, or lay the paper pattern on top of the wood with a piece of transfer paper in between; then trace the pattern onto the wood.
Your wood is now "dressed" and ready for a base coat of acrylic paint. You really don't need to paint on a primer coat unless you are painting on Poplar wood and you don't want the green or purple hues to show through. If you add a primer and then one coat of acrylic paint, you've just added extra expense. Save yourself the expense of the primer and paint the acrylic coat twice (since you would be painting twice anyway) to get complete coverage. Some acrylic paints are more transparent than others and the primer color will show through anyway. Skip the primer. The sealer will make the acrylic paint spread on smooth and go further (because you've sealed up the pores of the wood).
If you want to do decorative painting on top of the base coat (meaning you add shading and highlighting for depth and contouring), you will want to make sure your base coat is completely dry.
Once you are done painting, let it sit overnight to completely dry. Spray with a finish of your choosing to seal in the paint and leave a beautiful professional finished look. It will be dry in 24 hours but will take 3 days to cure.
P.S. Acrylic paint and spray paint don't mix......unless you use a painting medium that you mix into the acrylic paint, then you can paint acrylic paint on top of spray paint. The plastic in acrylic paint doesn't adhere to the chemicals in the spray paint. They don't like each other. This can be remedied by using an all-purpose painting medium that you mix into a sample of acrylic paint. (You don't need to add it to the whole bottle just to the amount you think you need).
I hope this helps. Happy painting!!
