Besides fender well lips and quarter panels, floor pans are notorious for developing body cancer. Leaking windows and T-tops let moisture soak into the carpet, and that moisture eventually turns to rust. When buying a car, looking at the front floor pans is usually part of the routine, pulling the back seats is usually not, which can lead to an unhappy surprise when you get it home.
All is not lost, however, as most popular cars have aftermarket floor pans available, if not complete, at least in patch panel form. The actual process of installing floor pans is really not that tough, especially considering the fact that nobody is ever going to see them, which makes them a perfect candidate to learn from for the novice builder. That is not to say that it should not be right the first time.
The tools needed to perform this task are pretty common and most any enthusiast builder should have them in his shop. A quality wire-feed welder is the biggest necessity, either gas-shielded or flux-core will work, though flux-core welders cause more splatter that will need to be cleaned up. Other than that, an air compressor, die-grinder and cut-off wheel are about all you need to get it done.
One thing that most builders leave out is weld-through primer. This high-zinc content primer is formulated to withstand the high heat generated by welding and is a must for any body panel replacement work. Available at any body supply or parts store, weld-through primer will keep the rust from attacking the fresh welds and sheetmetal from rust, particularly in those hard-to-reach places like overlapped and boxed joints. Once welded, the seams should be coated with seam sealer to finish off the job, ensuring long lasting protection from rust.
To get the lowdown on how to do it right, we took our ’78 Trans AM SE to Ramsey and Son Automotive in Stillwater, OK. We watched and photographed the process and brought it to you here. By following these steps, you should be able to replace the floor pans in your ride with ease, just take your time and do it right, the first time.
Ramsey Auto Body