Spray paint canisters might be cheap individually, but each one only handles a small surface area. This means you’ll often have to really load up on them in order to get a single large-volume surface area job done well.
You could make your own!
How to Turn Regular Paint into Spray Paint
Ordinary household paint, given a few modifications, can easily be made compatible with spray paint applicators. This can help get you out of a bind if you buy the wrong kind of paint, run out of spray paint on a job, or just can’t afford the extra costs of spray paint right now.
Prepare for this surprisingly simple process by setting out a bunch of work towels. It will almost certainly get messy. You’ll need spray bottles or aerosol cans. For this walkthrough, we’ll use household spray bottles. There are other much more complicated ways, if this isn’t powerful enough for your needs.
Take the bottles and clean them out. We don’t want any extra chemicals bonding with our paint and ruining its quality. Then add the acrylic paint to the container until about 70’s of the container is filled. Then add in just enough water to give the paint the same consistency as good spray paint.
The next step is to shake, let sit for a few minutes, and then to test! Odds are, the water will enable the paint to spray like real spray paint without getting clogged in the nozzles.
Here’s another way to make spray paint:
That’s that! Now you should be able to use your leftover acrylic paint as spray paint in any old spray bottle from a cleaned out Windex tube to a soap dispenser, but it’s best to stick as close to the guides as possible.