Community Alumni
May 07, 2018I use Fluid Film and it works well. Fluid Film penetrates the pores of the metal instead of just coating it. It lasts over a year for me, but I usually recoat once a year as part of annual maintenance. You can get it in spray or gallon cans. It's cheaper to brush or roll on the bulk of the job with the gallon can. The spray cans get pricey on big jobs. The spray cans are nice for those areas that the brush or roller can't reach. It's also good on things like locks and hinges.
You can also run it through an electric paint sprayer and spray it all on. I can run it through my sprayer without thinning and it's faster than brushing it on. For years I've pulled my trailer through the Salt Belt over the winter and most of the undercarriage still looks new.