So I applied corrosion free a few weeks ago to my truck. I also bought their high end spray gun which came with 2 spray nozzles, 2 different sized 45° wands and a 360° hose. The gun made applying so easy and I didn't have to drill any holes as I had wands that would fit the smallest holes.
I have to say their product is very impressive. I only used my pancake compressor and was able to apply it with no troubles. I was very liberal as it was a brand new truck and I had only a few drips from applying too much. The next week or two we had some warmer weather and I saw no evidence of dripping from the vehicle. Also as I sprayed the underside there was so little overspray in the air. I just wore a t shirt and jeans and I was not filthy after, I was pretty surprised!
I was underneath the truck the other day and it's still so thick, looks like someone dipped my truck in petroleum jelly haha. It does stink terrible as it burns off the exhaust also, I'll try to be more careful next year.
Corrosion Free is a food grade mineral oil based product. It's made in Canada and I bought it direct from them. They shipped it free and I had it within the week. While it's more expensive then FF I can still do it myself for much less than having it sprayed at a shop. Not trying to knock FF, I know it's a tried and true product just wanted to share my experience with corrosion free. I compared FF, krown, nh oil undercoating and corrosion free before making my purchase.