Build a Frame to Paint the Balusters
Place the balusters in an upright position to be painted. To do this, create a support for painting, start by inserting staples about 4 inches apart into a 2x4. Set the stapler so the staples don't drive all the way into the wood. Also, be sure to set the staples far enough apart to give the balusters ample room during painting.
Next, staple into the dowel end of each baluster so that only one side of the staple goes into the wood. This should allow a hook to be created.
Continue this process with the 2x4s until you have stapled hooks on your 2x4s for each baluster.
To create a work frame, use ladders as corners or end supports. Fill the middle horizontally -- and the sides -- with the stapled 2x4s.
Hang the balusters in rows onto the 2x4 frame (Image 1). Make sure none of the balusters touch and that you have access to both sides for even coverage.
Fill the sprayer with the manufacturer's recommended type of paint (in this example, latex is used). Keep in mind that oil-based paint cannot be used with many types of sprayers.
Begin applying an even coat of paint to each side of the balusters and allow to dry thoroughly before installation (Images 2 and 3).