Last weekend, in the pouring rain, I collected the steel for the base from Neil who very kindly sourced it for me and cut it all to length.
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It was all covered in a good coating of oil which has been doing it's best to get every where this week so I turned it in to a somewhat cleaner pile of steel by rubbing it down with a degreaser.
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After spending an hour or so cleaning it I decided to get a couple of rust spots off with a wire wheel which is when I discovered that I'd actually only managed to get a light surface layer of oil off, there's a much heavier oil still on the steel. My question therefore is this: how clean do I need to get the steel in order to paint it?
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The image above shows a very clean piece at the bottom and a pieces that have just been degreased above. I'm sure the bottom piece is clean enough for paint but are the other pieces? If I've got to get all the oil off what is the quickest method as wire wheeling it all will take ages.

Some good news though. I've tested a couple of the long rail pieces of steel with a reference straight edge and they are fairly close to straight <0.5mm in 600mm.

Cheers :-D