Published at Sunday, August 05th 2018, 13:41:22 PM by Haley Paul. Air Compressor. I returned to the job site with my new goodies and soon discovered that I had indeed made the right choice. The compressor started right up and was soon pressurized and ready to go. I hooked up the hose and gun, filled the reservoir with stain, and started systematically applying it to the siding. The portable air compressor was on wheels, and easy to maneuver. I could see the dry wood soaking up the stain and I was happy I'd opted for this method of application. I dreaded the idea of having to brush stain on for hours on end. Once I had the first coat on I let it set for a couple hours while I took a break, then went back out and applied a second coat. This probably would have been sufficient, but I had read that the very best thing to do when applying stain with a sprayer is to go back and brush over the job. Doing this really drove the stain into the wood and allowed it to fill every little pore.