I usually do not worry about any minor oil residue for the welding part. I just take paint thinner (whatever happens to be on hand) and wipe it down with a rag before painting. Keep in mind I am not painting show cars. Someone way more particular may have better advice for projects that require perfection. Also keep in mind as soon as it is cleaned it will get surface rust pretty quick. Not a big issue, but if you clean it and leave it laying around for a few weeks getting back to your project you may want to run some fine sandpaper over it before painting.
As far as metal sources there llikely is a metal supply house somewhere in the area that suppllies welding shops and construction. Check with your nearest welding shop. We go through our local welder as he gets a discount because of the volume he buys. If we need a significant amount the supply house will drop ship directly at our shop via their route truck. For smaller amounts we order it and pick up at the welders place as he gets at minimum weekly shipments. For very small amounts we just buy from the welding shop inventory he keeps on hand.
We are fortunate in that we have an excellent welding shop within a few miles that does quite a bit of work for us and he treats us pretty well.
Last edited by snrub; 01/10/17 08:25 AM.
