Hi all
I've been fortunate enough to manage a deal with my landlord in exchange for helping to restore his '74 Nova. (Specifically, replacing the subframe and the driver's floorpan for a month's rent.) That part of the project is mostly finished and it was pretty cool doing a floorpan for the first time. I now feel ready to tackle the Ford's

I found the rainleak that was causing the rust - it was in the cowl where the wiper arms rotate. The hole is currently drying with phosphoric acid on it to treat the rust. Then I can seal it up, paint the area, and have no more leak yayayay.

I have some questions about repairing the floor, though. The rust is pretty ugly in there, but mostly the floor is plagued by a series of small holes. I have extra sheetmetal handy and was planning on cutting out the swiss-cheesy area and welding in a new patch, but I have a concern about the floor's structure. When I cut out the floor, doesn't the whole cab sink down a little with the floor removed? Also, the driver's door closes much better with the front left of the frame supported by a jackstand; I'm wondering if better results will come by raising the body up, doing the work like this, and then putting it back on the ground. Thoughts?

Thanks guys

 

This is tough one to give you solid advice without any pictures to really see the extent of the damage.

If it was just the floor skin, you can just cut out the bad spot and replace with sheet stock or order a new pan. But you say the door closes better with the corner jacked up a little. That leads me to believe that either the framework around the mount is eaten away or all of the supporting metal around it (causing the floor to flex too much).

Check the structure of the cab that actually sits on the rubber mount and see how it looks. Pull up the carpet or mat and get a pic of the floor from the inside. Also, if possible, get a pic of the floor underneath. Like I said, it's hard to judge what's wrong (and needed) without actually seeing it.

 

I agree with ChopTop. Here's a shot of the passenger's floorboard on Dad's truck, and the doors close fine. So, I'm thinking you have problems beyond the floor.

 

Although I have no history on the truck at all, it does seem to have been in an accident at one point. The door may be askew because of that. (I've also tried to realign the door and the striker post better in the past. When I first got the truck I had to bend the top of the doorframe towards the cab more because it wasn't even making contact.) It really piqued my curiosity when the door closed nicely up on the stands.

Here are some pictures. There is a wonderful riveted patch over the worst hole, and some very interesting storm door threshold-like piece screwed along the length of the door jamb

 

Pull those two covers over the mount bolts and look down in there. I'm afraid from what I see in the first shot that you have quite a bit of rust around the passenger-side mount.

 

You must have incredible eyesight - these are photos of the driver's side only

For fun I pulled up the passenger side ... uhoh. Got a bit of work Bubbly rust all over there, but I think only one hole. Odd, but cool. I'll have to get those mount covers off eventually while doing the floor. I do have new cab mounts too ... eeeek ... maybe I'm "restoring" this truck now, heheh

 

Oops. It is actually BAD eyesight rather than good. But, check those mount areas out. Having said that, with the sill problems you may have several issues to deal with. Good luck!

 

Haha, I'm thankful for the help here - not a worry.
I suppose this is getting a little more involved but rightfully so. I want the truck fixed right at each step along the way. Maybe I will just put jacks under the body when I do the floor, which should help keep it all aligned. Definitely going to try and preserve as much floor as I can ... I'll put updates as they come along. (Warning - this is a bit of a "when I can" project." Just got done swapping cylinder heads on the Saturn which is now in tip-top shape)

 

We are all doing this "when I can". It is just that some of us "can" more often than others.

 

I like that notion a lot.

Thanks for your input; I look forward to having updates

 

Brendo613, look at my thread Major rework on 1986 F350. You will see how I did my floor repairs. Mine made no difference on stands or on the ground. I would take a real hard look at the frame.

There is also a sticky regarding resealing the cowl on mine.

 

From the pics you posted, it looks like all "light" sheet metal work. What you showed looked like one of my other trucks. You can order all the panels you need from LMC or another source. You can also get the lower weatherstrip edge. Just a warning though, the aftermarket parts DO NOT go together like the factory. Take your time, measure and test fit, test fit, test fit.

If you have a good welder, you can leave a .030-.040 gap between the panels and weld it closed (better than overlapping). What I do then is get some rubberized bed liner and strain it so you just have the liquid. Use a schuck (sp?)gun and apply liberally all around the repair. This has lasted for five years on mine (through Wisconsin winters) and still looks great under there.

 

ChopTop - Are you saying that a butt weld is better because it doesn't leave a place for moisture to hide, as a lap joint does? For floors, what if the weld for the lap joint is on the bottom and seam sealer is used on the top?

 

Yes, for that and cosmetics. The seam sealer on top (and bottom) is a good idea, then maybe a good coat of paint over that. Another thing that will help is using a weld-thru primer before lapping and welding, just to help deter the moisture.

I actually butt welded the tunnel in the '81 when I made and installed it. Just got that done yesterday.


I always try to butt weld any panels I put on or modify. I think I spend more time test-fitting than welding.

 

Wow, that must take time! I'm thinking about doing what Brendo is considering - replacing the floor. I have a donor truck, and from what you are saying that metal will be better than anything from the aftermarket. But, I was considering getting a flanger/punch and laying the floor in from the top, welding it on the bottom (the cab will be on a rotisserie), and then painting and sealing it all the way around.

Fitting pieces so you have just the right gap so you can hold it with a Cleco or somesuch sounds like a lot of work. What do you cut with? Plasma?

Brendo - I hope I'm not hijacking your thread, but ChopTop seems to know what you and I need to know, so....