I need to prune a red oak tree in August in Iowa. Can I use regular spray paint to seal the cut off branches?
First, the use of any kind of sealant on pruned trees is, as a rule of thumb, no longer recommended at all. Research shows that they can actually hinder proper healing of the wounds. Working with clean tools, cutting the right way and at the right time should be enough.
Second, you are falling into the trap of the English language's tendency to simplify things. While the wound sealant is sometimes labeled as "pruning paint", it's by no means a "paint", but typically a waxy or rubbery smear or paste.
So no, you can not use spray paint. Learn about how to prune your tree, clean your tools before the job, then leave the cuts alone.