Previous owners had patched small parts of the floor in the traffic area. Under the cabinets was mostly the original floor with the vinyl flooring in very sad state. Most of the vinyl squares came up very easily, the glue was so old and dry. This allowed me to see where the floor-to-frame bolts were.
I took the floor out in small sections. I cut each section by setting my circular saw depth at just under 3/4 inch . Since that is the thickness of the floor my plunge cuts did not hit the frame. I ran the blade just offset from the floor-to-frame bolt line. to avoid hitting any bolts. Then used a 3/4 inch hole-bit to drill around the floor-to-frame bolt heads that I could see. I could then remove that piece of flooring. The floor bolts were all rusted so I simply used my grinder to cut them down to the frame.
I removed the old insulation to expose the belly. The frame had only surface rust, no flakes except right under the door. Not surprising since that area was permanently soaked from major leaks.
I only removed the floor back as far as the rear of the wheel well in this first phase.
Below is a photo (apologies for the blurriness, its an old phone and middle of winter so not good light) looking towards the rear of the trailer. Surface rust on the frame and some surface corrosion on the belly panels. This is before any cleaning, just with the insulation removed.
Below we are looking towards the front. I have removed the center inner skin panel and the bottom rivets of the curved side panels to access the C channel screws.
For a great description of how Silver Streaks are built here is the best link I have found: http://www.sandridgeairpark.com/SilverStreak/. Those folks have done a superb job of documenting their restoration. Their highly detailed posts show exactly how these machines are put together. Thanks to them I knew how to proceed with the floor repair.
Below I have cleaned the frame and belly with a wire brush, then acetone. I also have applied my first coat of Corroseal, a rust converter that I highly recommend. You simply paint it on. It starts white and turns black where there is rust, dries clear where there is none. You don't have to get the frame crazy clean, just wire brush well, acetone to clean and apply. Paint it on thick and don't be stingy with the product. I put several coats on the entire frame and also on the belly to stop corrosion. I had a small electric heater running non stop to help the drying process, and also to keep myself warm. Since the temperatures were in the 30's it would take overnight to dry. I cannot say enough good things about Corroseal. In the photo it still looks milky but will dry to all black. Cant seem to find a photo of the frame all done but believe me, it looked nice!...
