Addressing the Underside Visual Advice

If you decide to strip the undercoating, I soaked mine down with PB blaster, let it soak overnight, most of it then scraped off with a putty knife. Had to give it another shot or two in some places. Then I use a few different scrub brushes, brooms, dustpan broom, whatever soaked in Dawn and scrubbed it down, and hit it with the sharp blast from the hose. Did that a couple times two. Different scrub brushes, brooms, dustpan broom, whatever soaked in Dawn and scrubbed it down, and hit it with the sharp blast from the horse. Did that a couple times too.
Like I said, took a couple times, but the work was not hard at all. Found some rusty spots I didn’t know I had.