Im painting my engine bay today with some POR 15 paint... the black red colored can..... I had a question i know some people of used it and i wanted to ask if you use anything to tin the paint like a paint tinner or something..... im paintin it on metal. I took off al the paint in my engine bay.....

 

If you are painting with a brush, you don't have to thin. If spraying you must thin with their thinner. Apparently the only thing that works. Also, if you got everything down to nice shiny clean metal, they recoment using their "Metal Prep" to help the por 15 adhere to celan metal. It says right on the can that it is best on seasoned metal.

Their metal prep is expensive though and it is just phosphoric acid that leaves a coating of phosphate on the metal which is a god rpep for paint. You can get essentially the same thin at Home Depot for alot cheaper, it is call Phosphoric Plus. I use it all the time. Search my user name as I have done a couple write ups on my process.
Hope that helps, good luck.