I let my first shock bracket "cook" for 3 hours
with periodic brushing with a wire brush. I don't think it needed to be in the process that long, but I was painting too, so I just checked it when I had time. It was, by the way, very heavily rusted. Later today I'm putting in the other bracket along with the flat U-Bolt plates all wired together. I'll let you know how long that takes.The nice thing about this process is that it doesn't require a lot of attention so it's almost a side job.
