What's the best way to take care of a rusted floor pan? I have a 1977 Comet that's probably lived in the Pacific North West it's whole life, It runs good, and I've been working on it ever since I bought it back in 2012. Recently the seatbelts became frayed so I decided to finally replace them, and the carpet and the sound deadening as well as take a look at the floor pan. When I got the sound deadening off I found this: Which after wire brushing turned out to be this: So not great, but not a total disaster. Now my understanding is I have 3 options for repair: 1. The option I probably will not use, I can use Bando body filler and patch the holes and then redo the panel seals and repaint. 2. I can cut out the rusted sections and install new floor pans and weld them in. 3. I can use fiberglass resin and fiberglass cloth, get all the rust ground off, fiberglass, sand, seal, prime and paint. At present Option 3 seems like the best option to me given the nature of the rust, the degree of skill required to weld in new floor pans (I've worked with fiberglass before and with Bando, and I am confident with fiberglass. Also, Fiberglass can't rust. Opinions? What and Why?
Seal the rust then fiberglass. Rust finds a way around glass, so I would Por 15, 3M or similar first. Good luck. Maybe body panels change.
this is what I did to my (rust free) cowl and inside of the quarter panels just to keep from rusting. been 10 plus years and still no problems or rust... Jeff has some really great pics. of what he did to his car, maybe he will post some of them. Trunk Pan (and floor pan ) Repair for the Non-Fabricator
Here is an old thread from when I first used Rust Bullet - still as solid as ever after 16 years http://mmb.maverick.to/threads/just-tried-rust-bullit-floorboards.11670/ .
The "correct" answer is to cut out the rusted through areas and replace them with new sheet metal. Honestly I'd hate to put in all new floor pans on something that good. Now that you have the correct answer, lots of people manage to get lots of additional years out of their cars before they have to go to the trouble and expense of full floor replacements by means such as Rust Bullet, POR-15, fiberglass and the like. As cool as these cars are they're never going to be worth the six figures of a MoPar E body with a rare engine. Hard to tell from the picks, but I'd consider cutting out that thin area near the trans tunnel on the curb side. Beat a panel to fit the contour before you cut, flange it in, weld through primer, spot tack it in and seam seal top and bottom. The rest of the floor looks pretty darned good but keep in mind it's a unibody...the floors are important to structural integrity.
My car has been in the Portland, OR vicinity all its life from what I can tell, and the trunk floor looked like your floorboard....possibly just a little worse. I could not get into the trunk when I bought it, for which I am grateful, because the rust in there might have scared me away. I cleaned the surfaces with a wire brush, vacuumed, slathered on POR15, laid a layer of fiberglass mat, more POR15, a layer of cloth, POR15, and a layer of mat, and a little more POR15. I prepped all my layers for fit before I started. There was no dry time until I walked away from it. No sign of rust after 5 years. I throw this in just to let you know that these products are not that fussy, and fool proof to some degree. Very tough and durable......do not get it on your skin and throw your applicators away. I suck at welding, so for me it was an easy decision. Also, my car is not, and never will be more than a hobby car and I have a tolerance for quality imperfections. At least I didnt catch it on fire.
