If you decide to weld it then you need to clean it very well. Get any grease and oil out of the weld zone. Grind the paint off. Then get it hot with a torch, about 600 degrees. I know, that's hard to judge. Just get it good and hot. Then weld. Your welder isn't really up to the challenge on cold steel this heavy, but pre-heating will make it possible to get a good weld. Not one that just looks good but one that has penetrated. All oils must be cleaned away because they are full of hydrogen. When welding oily steel the hydrogen coming out of the oil will dissolve into the molten steel in the weld. As the weld cools the hydrogen will come out of solution. This will show up as porosity which may not be visible unless the weld is ground on a little. The hydrogen also causes the steel to become brittle. So with the porosity and the embrittlement and poor penetration the weld loses most of its strength, even if it looks great.
Good Luck,
Eric
