Morning everyone My chassis is very rusty I have welded up the rear by the tank now most of the time chassis normally rot from inside out but mine has paint inside but the outside is very pitted has anyone experienced this I have been round it with a big hammer and plenty of oil it doesn’t really do much off-roading or wading I can’t understand why my chassis is very pitted on the outside but really good condition inside does anyone have any suggestions how to solve this thanks