The cement mixer (with added Sulphuric Acid) is always a good option,but....
It may be a false economy ...... really good fittings: Drop Forged Little Giant, Mills, Band and Plate.......tend not to rust a lot, and the only part that really matters is the Nut and Thread of the Bolt.........
Invest in good quality secondhand of the above and toss the pressed steel...(if it wasn't made in Birmingham it's probably crap) at anyone who you think may be in our country just because they hate us.....you know it makes sense