Rust - How much is too much?

[katsi]

I'm kinda at a point where I don't know wether or not to scrap my project and start a new one and keep mine as a parts car. Although, the shock towers are all good and rust free, the floor pans are a different story. I know the replacements are cheap enough but, the rust seems to be in the transitions. For example, where the floor pans meet the center "hump" a good foot or so of that transition is rusted out on both sides. Also, on the passenger's fender well - I see alot of daylight. This was not originally visable as the PO had done some repairs but underneith those prpairs is something different (basically, i discovered that the PO had fabricated Aluminum floor pans and rivited them in place to the good metal and basically just covered up the old rusty parts and did nothing to them). The support beams seem to be in good, solid condition ( I can jump up and down on them without any squeeks or movement and no visable signs of rust here) and where the rear end bolts up to the beam behind the seats is in good, solid condition as well. But, one hole underneith that beam about the size of a nickel. 3 of 4 seat rails are still good. Passangers inside rail is beginning to rust but still firm (this is where the transitions are rusted). The Body itself is virtually rust free - excluding dented areas and places where the paint has been scratched. Nothing rusted through on the body. No rust in the engine compartment on the sheet metal.

[Kevin1]

We've all seen plenty of Spiders with repairs made to the floorpan, so your situation isn't too unusual. Your best bet would be to get an opinion from a good body shop that does restoration repairs. Some shops will not touch it, though, they only do collision repair. Another place to look for hidden rust is the inner rocker panels. Again, a good body shop can go over the car and determine what really needs to be done.
From what you describe I wouldn't write it off yet. The real issue is going to be money. It may end up more expensive than it would be to just find a car with a solid body.

[mdrburchette]

I would do what Kevin suggests. Take it to a bodyshop and let them tell you what they think. The problem with rust is if it is apparent in places, it's usually hiding in others. Especially in your area, you'd probably have good luck finding a rust free Fiat at a reasonable price. Be glad you're not on the East coast!

[htchevyii]

In my opinion, it's tough to find a convertable with no rust in the floor. Unless it's been garaged it's whole life, water gets under the carpet. I think the floor is the easiest to repair, since it's hidden from view, the repair doesn't have to be perfect. Sure, total replacement is best, but with a lot of elbow grease I've had good luck using wire wheels, metal prep (rust remover) and master series paint. If out remove the rusted metal first, you can get away with overlapping panels and save some work, but make sure you paint/seal the seams well. If you don't have a welder, you could pop rivit patches over smaller areas, but cut out the rust and paint first. Of course if you have the resources it's better to weld in new metal.

[baltobernie]

Nice thing about welding underneath is that nobody ever sees it! So it doesn't have to be pretty. Also the metal is thick enough so that blow-thru is less of an issue. But it would be nice to have a rotisserie, so the slag doesn't drip on you. Somebody is going have to weld it; those floors are an integral part of the unibody, and Pop rivets ain't gonna cut it.

There are some very inexpensive MIG welders out there; some of which operate on 115 VAC household service. They even have flux-core wire, so you don't need a separate gas bottle. In addition to the welder, you should get a shear like this; cutting 14 ga. with snips is brutal http://www.harborfreight.com/cpi/ctaf/d ... mber=38413

You failed to mention the engine crossmember condition. Check this too before making a decision, but it sounds like your project is suffering only from standing water, not corrosion from daily use. If the powertrain and other items are good, you may have an instance where the principal investment is your time.

[katsi]

HMMMMMM! Well, you guys brought me in the exact full circle I've been going through in my head.

[htchevyii]

"Somebody is going have to weld it; those floors are an integral part of the unibody, and Pop rivets ain't gonna cut it."

Airplanes are rivited togeather and I'd guess they are under more stress then a FIAT floor. I did say small patches, but I agree welding is better. When I was young and poor I repaired several floors his way and never had an issue and these were unibody V8 cars.

[katsi]

Here is an interesting conversation I had the other day with a guy from Dallas. Apparently, he lives very close to a Fiat place called victoria's or something - he he. Anyway, he said the guys ther were very great at answering his questions and that the guys there sudgested pop rivits and fiberglass as a good alternative to new floor pans. Take it for what it is. I think I need to bursh up on my welding skills. I think a MIG welder is going to be the best for this project.

[htchevyii]

Here's a smokin' deal on pans on Ebay:
http://cgi.ebay.com/ebaymotors/FRONT-FL ... ccessories