Saturday, June 17, 2017

Triumph Spitfire Body Repair #2 - LH Floor Pan Removal / Repair



I ended the last post with saying I was going to build a rotisserie. As it stands right now, those plans are on hold. The boot floor on Dorothy is not structurally sound in the least. Thankfully, I was smart enough (or just lucky) and fabricated the supports to hold the rear of the car to the rotisserie before I started hacking away at the new engine stands. For my design (which I stole from several pictures), the rear support is bolted into the existing holes in the boot floor used for the rear bumpers. As a proof of concept, I attempted to lift the body from the new supports and the boot floor started to come apart a bit. That's not going to work, obviously, so no joy for now.

But, with the front bulkhead repaired, I tacked the front support bracket back in to allow me to remove the floor. I didn't get good penetration on all of the spots, so I'll have to revisit this, but for now it was okay and would support the body.

Not pretty...and this side was better than the other one.

With that done, I decided to just go for it and cut the driver's side floor out. I was conservative with my cuts and left a lot of the original metal to allow lots of wiggle room when fitting the new floor pan.

Rear near the heelboard.

Rear at the radius arm bracket. I revisit this area extensively!

Front showing extensive damage to the lower A post. Should have bought one for this side, too.

The old floor. Lots of Swiss cheese, there.

Since I just took a cutting wheel to it all, I had quite a bit of old floor still attached to the sills. This had to come out to allow me to properly fit up the new floor. Speaking of that, the order in which you do this common repair to the Spitfire is important. Given that the floor and sills need to be replaced, the floor is done first. The construction of the sill parts and the floor is like one big sandwich. The floor sets the base and all of the rest of the sandwich is built from there. So, to replace them, you start with the base and work your way out to the outer sill.

L to R: Floor, inner sill, middle (strengthener) sill, outer sill.

Another angle. Note how the inner sill sits on top of the floor. It won't lean in when installed, either.

My first thought was to just take the cutting wheel to the bottom seam and cut it away in about 30 seconds. On second thought, however, I didn't want to take the chance of compromising the dwindling integrity of the structure. Most of the bottom of the inner sill, especially towards the front, was gone. This left its top, the middle strengthener, and the outer sill as the only things connecting the car front to back (except for the support that I put in between the A and B posts). Better safe than sorry, I cut the welds of the floor with my Blair spot weld cutter. For the few spots that didn't cut fully away, I chased them with a standard wood chisel that I picked up at Harbor Freight. This thing does surprisingly well given that I literally bang the crap out of it to cut metal. I have had to grind the edge a few times, but it's holding up well.

Floor part removed. Extensive damage to bottom of inner sill.

Inner sill gets better, but still some pinholes. Lots of spot welds!

The problem corner. It gets worse.

After getting the part of the floor removed, it was time to remove the remaining bits at the back, under the heelboard. Again, several spots welds needed to be cut away to separate the floor from the heelboard. I had to do this on my back, but it wasn't too bad. I used the cutoff wheel to section the pieces out a bit to make it easier, but I was very careful not to cut into the heelboard.

The following four pics are from the floor looking up, with the front of the car at the "bottom" of the pic.

Floor attached to the heelboard and rear radius arm bracket.

Seat belt mounting eye hole in rear of floor, reinforced with a plate of 16 gauge steel.

Bottom of rear radius arm bracket. Yuck.

With the floor now fully removed, I stepped back to assess for any further damage that I needed to attend to prior to fitting the new floor. Of course, I found some. First was the rear radius arm bracket. The bottom was in pretty sad shape with some metal loss and gross pitting. Given that this is a suspension mounting point, I chose to replace it.

Metal loss. The spot welds holding the bottom part to the bracket are rusted through, too.

I cut the spots welds to remove the bracket. Unfortunately, I didn't understand how the bracket was put together. There are two main parts. A heavy (16-gauge) L-shaped piece serves as the base. The bracket with the bolt holes is spot welded to that L-shaped piece and the radius arm bracket bolt holes are attached through both, capturing them as well. I didn't understand this to be the case, so I tried to just drill out the smaller bracket part and finally figured out that the bolt holes were holding it all together. I drilled out the larger, L-shaped base and it came right out.

Bracket removed.

The black car's brackets were in fine shape so, between the sawz-all and cutting wheel, I got the old brackets out with little problem (I assume I'll have to replace both sides). I cleaned the driver's side one up as best I could and primed it with the Dupli-color zinc paint for when it goes in its new home.

"New" (L) and old. You can see my mistaken first attempt at drilling out the spot welds.

With the bracket out, I made another close inspection and found some pinholes in the heelboard. The pitting was rather extensive, however, so this would have to go as well. Making my way to the "B" post, I noticed some damage behind the inner sill.

Lower "B" post damage. You can also see one pinhole in very bottom of heel board. There were more.

I cut a portion of the inner sill away to get a better look. I figured there would be more damage behind the portion of metal I was going to cut away in the heelboard.

A portion of the inner sill removed to show damage.

Assuming there was damage behind the spot welds that connected the heelboard to the "B" post, I made a template that was bigger than I really needed for the heelboard itself. Hopefully I won't regret cutting away extra metal, but I doubt it.

Template made for piece to replace in heelboard.

Result of template.

Of course, when I cut away the portion of heelboard, I found the damage I expected.

Extent of damage. Sorry it's blurry.

To better assess the full damage, I decided to cut away a portion of the front lower rear wing. I knew I was in trouble when I had to grind through about a pound of Bondo.

The top of the Bondo line.

Bondo all removed. Cut away portion marked.

I didn't locate any further damage that I had to address with this repair, so I templated a new piece for the lower B post. Of note, I am using manila paper for my template material. After I make my template, I cut the new metal and form it as much as possible BEFORE I cut away any old metal. Except for shooting the area with zinc primer, I try to get to the point of being ready to weld in the new piece before I cut any old metal away. That way, I don't cut more than I need to and could regret later.

Template and new metal. Odd shape, but that's how it went.

All old metal cut away and area primed. Note the little tail piece of rear wing that I left to clamp the new piece to.

Initial fit up...some adjustment required. Note the clamp at back on that little tail piece.

Several tacks. Good enough for the day.

I was running out of time for the day, so those tack welds finished it up. You may have noticed that I didn't put the hole in my new piece that was in the old. That's because I was afraid I'd blow the weld out since the hold was very near the weld seam. My intention is to go back, after it's all welded in, and drill large hole. The rear wiring harness will run through there so I'll have to clean it up good. Hopefully I won't regret doing it this way.

Anyway, I'll get that in and cleaned up, then put in the heelboard piece and clean that up. After that, I'm going to put the rear radius arm bracket in, but only with the bolts. That way, I'll be able to adjust it based on how the floor will fit in its final spot and then I'll make it all permanent!

I did briefly fit the floor before I left. I have some adjustments to do, but it looks good!

The future!

Here's wishing all those Dads out there a Happy Father's Day. I'm taking the boys fishing tomorrow so we'll see how that goes!

1 comment:

  1. Nice. Both my floors and sills are lost causes so I'm going to be going down the same route.

    ReplyDelete