I spray a lot of roundup, 2-4d, remedy and soon remedy/reclaim mix. I have a 26 gal spot sprayer but continue to use a pump up unit to avoid corrosion because their all plastic. Is corrosion a problem with sureflow pumps used with these chemicals and how do you work to prevent it? I was thinking to rinse it after use and maybe pump some vegtable oil through it afterward. I'm thinking vegtable oil because I may want to use it for something other than killing everything, so petro oil residue may be bad. Will vegtable oil prevent corrosion enough? TIA, MP