Floor Pan Install - 65 Dart Convertible

[PocketAces]

The floor of my 65 convertible had rust in the back seat area. From the bottom everything looked pretty good, with lots of engine oil and tranny fluid to keep the metal protected from the elements.

But when I pulled the carpet, the inside was not so nice. The front foot wells were solid with surface rust only. The rear foot wells were very thin and rusted through in places. It was worse on the right, but there were pin holes on the left as well.

Also the center section was badly deformed, probably from a previous owners installation of non-original seats. You can see the extra holes that were drilled. They also did some beating with a BFH. This altered the height of the stock holes so the stock seats were not level.

 

[PocketAces]

I found a floor in a salvage yard in Brewster Washington, Shull's Auto Wrecking. I found them while hunting for a nice front fender. They had a 65 4 door economy model with rubber floor mats and radio delete. I ended up buying quite a bit of that car, including the floor pan.

The donor car had rust in the front foot wells, but the floor was solid in back. I asked them to cut it just behind the cross member and again up under the back seat. They included the front cross member and the rockers which was probably good because it kept everything rigid in transit.

Heres how it looked when I got it. Still has the original paint. It must be really dry in eastern Washington state.

 

[PocketAces]

First step is to extract pan from the assembly.

I used a Harbor Freight spot weld cutter. That thing really cuts and it was very easy to drill clear through both layers of metal. Not a problem on this piece, but when removing the old pan from the car, it's very important to only cut one layer of metal. I tried hard to do this here as well as practice but I went clear through several times. The best technique I discovered was to get a screw driver wedged between the two layers of metal on either side of the spot weld if possible. This puts tension on the spot weld so that it will pop when you get through the first layer. Otherwise, it's impossible to know when to stop drilling. Carefull though, because they don't always pop.

Another challenge is to find all the spot welds. You have to clean off all the seam sealer and rust. Then a quick hit with some 120 grit sand paper brings them out nicely. Also getting them wet with some spit on your finger can help you see the outline.

You definitely need to center punch them with a nice sharp center punch. Otherwise the cutter will wander all over the place.

The last picture shows the pan free and clear of the old cross member and rockers.

 

[DJVCUDA]

looks good - cant wait to see the rest of the progress

 

[PocketAces]

Next step is to remove the old pan from the car.

I cut across the old floor about an inch back from where I cut the new floor. This will give me an overlap to start with until I can set the new floor in place use it as a pattern to mark the real cut line. I'm going for a butt joint and I plan to grind the welds smooth. I want the repair to be as undetectable as possible.

When removing the new pan it was important to preserve the pan, but OK to trash the rockers and rear floor section. Now I can trash the pan, but I have to be careful to preserve the rockers rear floor section.

I tried using a bottle jack and a 2x4 to lift up on the pan and put tension on the spot welds. But it didn't work. Screw drivers seem to work best.

You can see that the console mounting bracket is behind my cut line. I took careful measurement before cutting. Hopefull it won't be too hard to get this back in the right place. I also measured the mounting points for the convertible top cylinders and the convertible side panel mounting bracket. All these will have to be transferred to the new floor in addition to the bucket seat mounting reinforcements.

Here's the old pan, half way out. Did I mention this is a lot of work!

 

[PocketAces]

Yabba Dabba Doo

 

[PocketAces]

Here's the new pan setting in place. It was a challenge to get this in there with steering wheel in the way. The sides of the car lean in a bit so you have bend the pan at the hump to fit it down into the car. Not sure if you could do a one piece pan swap this big in a hard top.

Just sitting in place the new pan feels pretty strong. The old pan was really thin from the surface rust and the rear foot wells would oil can when you stood on them.

In this picture you can see the holes for the drain plugs in the front foot wells. I left these holes in tact on both pans so I can use them for alignment. I assume these holes are punched by the press when they stamp the pan so they should be in exactly the same place on both cars. If these line up, I have to be in the exact correct position. After I mark my new cut line on the old floor, they will get cut out of the old floor.

 

[PocketAces]

Here's a better picture of the original rust in the rear foot well. The driver's side is not quite as bad, but it very thin and rusted through in a few spots.

 

[PocketAces]

Next step is to mark the final cut line on the old floor. To do this I set the new pan on top of the old pan, aligned the drain plug holes, and screwed the pan down to the rocker with screws. Then I marked the cut line with a sharp pencil.

 

[PocketAces]

Next, I removed the new floor pan and cut along the line with a die grinder and cut-off wheel. Keep the curf behind the cut line. You can always grind away metal, but it's hard to put it back.

I used some roof flashing to protect the tailshaft and u-joint. The vise grip and hammer are holding the brake and fuel lines down away from the floor. Duct tape protects the steering wheel while putting in and taking out the new pan.

 

[PocketAces]

After a quick pass with the grinder to clean up the cut, I put the floor back for a test fit. To eliminate gaps in the butt weld, I marked the spots that touch with chalk, pushed the pan back a few inches and hit those spots with the grinder. Wipe off the chalk and repeat the process until there is a tight fit with minimal gaps.

 

[PocketAces]

With a fit like that even I should be able to make a nice butt weld, knock on wood.

 

[PocketAces]

Transferred the bucket seat reinforcements from the old pan to the new pan. Got some help from FABO on the exact location for the bucket seat holes. Thanks to Bill Grissom and 65 Dartman.
http://www.forabodiesonly.com/mopar/showthread.php?t=195448

First drilled out the spot welds from the bottom of the old pan. Hit the bottoms with a 36 grit grinding pad and then put them in the blast cabinet to clean them up. Painted the bottom of the brackets and the top of the new pan with brush on weld through primer. Used some bolts and washers to hold them in place and and plug welded them from the bottom. The big one in the last photo had to be done again because I didn't get good penetration in the plug welds.

 

[65dartcharger]

You have done an extremly good job on your car. That will make a great result.

 

[65Val]

I did exactly the same thing on my '65 Valiant 'vert....cut out a good floor pan from a wreckers 4-door Val. Drilled out spot welds on the car and the floor pan, and welded floor pan at the original panel seams. Looked totally stock when done, top and bottom!

Here's the floor out.....

 

[PocketAces]

Started welding in the pan. Tacked it across the front and made some plug welds along the rocker. My daughter's bedroom is right above the garage and she goes to sleep at 9:30 which is really cutting into my productivity.

I'm having trouble getting my welds to lay flat and so I have to do more grinding than I'd like. I did find that if I scrape away the weld through primer from the bottom layer of metal inside the hole, then I get a better result. As it is, I grind with a grinding wheel taking care to only grind the weld and not the surrounding area. Then I switch to a 36 grit sanding disk on a different grinder (helps to have two). Finally I hit it with 60 grit on the DA sander. This leaves a pretty smooth finish. The car will eventually be media blasted which will further obscure the welds and grinding scratches. The seam sealer will no doubt hide anything remaining, so perhaps I'm spending too much time for nothing. But the goal is to have an undectable repair from the top or bottom.

The second picture shows my attempt to draw the pan down tight prior to welding, using screws, clamps and a scrap of wood. You can see the bracket for the convertible top cylinder that was transferred from the old pan. Everything is fitting very well.

 

[65Val]

Yes...seam sealer hides a multitude of sins....don't get too hung up on making your welds look great....the carpeting and such will hide it all.

I used a crap-load of self-tapping sheet metal screws to hold the panel in place for welding.

Lookin' good. (This is deja-vu for me)

 

[jerry6]

Looks great , absolutely amazing work .

 

[Woods74]

If you run out of that weld thru primer, rustoleum hi-temp bar-b-que paint works excellent. Good job!

 

[PocketAces]

I invented a tool for holding the seams together to get a tight weld. It's a length of 5/8" threaded rod with a grinder backing plate screwed on the end. It's just the right length so I can lean on it to hold the panels tight together while welding.

 

[PocketAces]

Finished some more plug welds last night. I worked from the tunnel out before welding down the outside edges

 

[PocketAces]

Here's some pictures of the butt joint across the front. I spent a lot of time grinding and sanding the weld. I have the weld looking pretty good from inside the car. After I get the car on the rotisserie I will do the same to the bottom.

I feel like I got really lucky not having to replace the front of the floor pan. There are a ton of spot welds on the cross member and the front frame rails. It would have taken a lot longer to drill out, plug weld and grind all those spot welds.

 

[PocketAces]

Locating and welding the brackets that hold the convertible side panels.

To find the right position I installed the panels and screwed the brackets to the bottom of the panels. Then I tack welded the brackets to the floor, making sure the panels were in the right place. The photographs I took before removing them helped as a sanity check.

The original brackets were not positioned the same on both sides of the car. Now they are. The position of the front of the brackets is based on a good fit between the side panels and the interior panels. There is some flexibility in where you position the back of the brackets. I cheated mine in-board a bit to make room for speaker boxes I plan to make for the space behind the side panels. I now have enough room for 5 1/4" speakers firing up out of these spaces. Here's another post on that. http://www.forabodiesonly.com/mopar/showpost.php?p=1802245&postcount=19

 

[PocketAces]

Here's a final shot of the floor now that all the metal work is finished. I still have some grinding and sanding to do on the bottom of the car, but I won't do that until the car is on the rotissirie. Then the car will be media blasted inside and out. This will remove all the remaining paint and also obscure some of the sanding scratches in the metal. I stopped at 80 grit.

 

[PocketAces]

I hit all the bare metal with some primer. I know this will all get removed when the car is media blasted, but until then it will prevent new rust.