Vintage Cars: Floor pans, ladder frame, porsche 911


Question
In doing some casual looking for a classic car, I frequently come across references to good or bad floor panels, or pans, regarding rust. I know some rust out due to road salt and lack of care while others do not because of better care. My question is: How difficult and expensive is it to replace or repair badly rusted floors in a classic car? Is it mentioned so often because of the large number of rusted ones? Or the expense of repair/replacement? Both? Thanks for your help.

Answer
HI Tom,

Well it really depends on the type of car, the type of repair you want to do, and the extent of  the damage.

Some floor pan rust is localized and not structural, and this isn't hard to "fix". It is hard to make it look like it wasn't fixed, though. Big ugly welded patches under the car, or rows of pop rivets, really turn off future buyers or show judges.

Some cars, like unibody (floor is part of car's strength--it is a substitute for a ladder-frame) constructed cars, could actually be nearly unfixable if the floor rust has eaten into areas where the floor joins the firewall or A or B pillars that run up to the roof.  A Porsche 911, for instance, with severe floor, firewall and A Pillar rust, is probably a throw-away.

So, a small area of rust from damp carpets in an American car, no big deal. A large expanse of rotten metal running to rocker panels, firewall, and A-B-C pillars, watch out! A major undertaking.

Hope this helps,

Joe Troise