Best method would be to remove the powdercoat from the underneath and fish oil it and give it a clean and fish oil it again every few years. I'm cleaning my spouting out around the house at the moment and painting them again with fish oil. I have 6 cypress pines and a silky oak hard against my fence that never stop filling the cutters 24/7. The gutters are 39 years old and I hope they last another 20 years and then they won't be my problem. Last time I fish oiled them was probably 15 years ago and it is really only the side where these trees are that is showing signs of not being too happy. Every mower I repair, apart from alloy decks gets cleaned and fish oiled in the areas that are known to suffer from rust, I don't paint the entire underside because fish oil is expensive and at the end of the day the only one who cares about these mowers is me, most owners would not give two hoots about how much time and effort I put into their mowers, all they want it to do is cut grass. I had a bloke come here today with his father because his father wanted a mower as the son had bought one from me a couple of years ago. When I asked him what mower it was all he could tell me was that it was green, as then asked him if it was a 2 stroke or a 4 stroke and all he could tell me was that he thought it was a 4 stroke
