One of our forum members wanted to know how to replace a floor. So here goes a quick overview. Please note I have missed out the basics of cleaning rust, paint & sealer etc & presume you have some experience. If not you might want to get some local advise from someone who knows what they are doing.
Here's a little run through of the process of replacing a floor.
Now this depends on the welding equipment you have, but I am going to presume you only have a mig welder.
1. Drill through spot welds on the lower outer sill section that is welded to the floor. I have already replaced the sills & will probably spot weld mine.
2. Drill through spot welds on the inner sill that is welded to the floor. Again I have started with a new sill.
3. If you haven't already done so you need to remove the sound deadening pads from the areas you will be drilling/welding. The easiest way is to warm it up with a hot air gun and then use a scraper and it will leave barely any left. This can be cleaned with a degreaser or a clean'n'strip wheel.
4. Check where your new panel will go, sometimes best to mark where you are going to cut with a pen or masking tape.
5. Use a sharp bolster chisel and a large hammer to cut the bulk material away. Use the corner first to start the cut then keep it at an angle to slice through the thin steel.
6. Once the bulk is removed, clean up the rear foot well area slightly to expose the welds. There are some large ones that hold the rear floor strengthener together. Then there are some small ones that hold the floor to the rear floor section, these are the ones to drill all the way through with a larger drill bit. These holes will be used to mig weld through later.
7. Then go to the front foot well section, expose the welds, this time you just want to drill through the first layer of metal. Ideally use a spot weld drill or alternatively use a grinder.
8. Break all the joints by hammering a thin blade/scraper in between the panels to break any welds not fully drilled out.
9. Then use a grinder to remove any burrs on the remaining surfaces and use a hammer and dolly to dress all the joining surfaces nice and flat ready for the new panel.
10. Where the floor meets the centre tunnel, just dress this up with a grinder for a neat edge, hammer it up flat & clean the surface of paint/sealer as the floor will be welded to this surface.
11. Prepare the floor. Don't forget to make sure the front jacking points and seat belt anchors have been welded to your new floor first, its far easier than doing it after. Then clean the paint from the areas which are to be welded as the mig welder does not like paint.
12. Try the floor in place and make any minor alterations to fit nicely. I had to cut a small section out at the rear near the inner seat belt so the rear section can fit under the floor and the inner length can go over the original lip. I also had to trim up the seat rails under the floor as they were slightly too long.
13. When you are happy with the fit, either drill holes or use a punch along the areas you want to weld. Make sure the surfaces are tight together. Mig weld through the holes, then grind the welds flat after.
Unfortunately I have to remove the centre tunnel section due to corrosion so I cannot weld mine in yet. But hope this gives you the idea.