driver's side floor repair--If at first you don't succeed...Part 3

It's that time of the year when my schedule and activities start getting borderline crazy between home and church.   I'm just catching my breath after the Thanksgiving weekend of cooking (and mighty tasty too, I might add) of smoked turkey, Paella (pronounced "Pie-A-ah") and two stock pots of Jambalya--New Orleans style.   I didn't get to work on the fastback as hoped with family in town.  But  I did get to build a play house for my 3 year old granddaughter out of an HVAC box, that she played in all weekend.   But I digress...

I had a couple of hours on Saturday afternoon to start playing with the "filling the gap" process.  The first thing I did was to get the floor positioned so that it was tight against the inside rocker panel and the best fit possible to the rear edge of the front to rear butt joint.   I used these magnets I've had sitting around that worked well in holding the floor in place.

After seeing the nice fit with the magnets pulling the floor and firewall extension together, I thought I'd go ahead and do the plug welds.  Holy Cow!   That was a huge lesson in electromagnetic phenomenon!!!   The welding was anything but good.  Apparently, the magnetic field disrupted the electrical current.  Duh!  Should have thought of that.   Anyway, the floor didn't move at all with the magnets.  I put a few plug welds in the middle of the floor to attache the floor to the frame rail. 

Then I put a couple of plug welds in the floor to rocker panel flange on each end and the middle.  I had what looked like a good gap on the rear butt weld seam with the body clamps fitting tightly and put in a bunch of tack welds.  

I moved around putting more welds in the rocker panel, the front floor to firewall extension, and the rear butt weld.  I figured I'd deal with the gap at the transmission tunnel last since that's where the biggest problem was. 

After hearing from a number of you, I went with the "Glenn method" of using wire to fill the gap.  I got a 1/8" diameter rod at Lowes, but couldn't find anything smaller.  Neither Lowes nor Thrifty Supply had any TIG rods, which would have been 1/16" diameter.   But then I remembered I had a box of insulation support wire left over from building the house.  These are about 17" long and are used to hold up the insulation bats between floor and ceiling joists. 

The 1/8' rod is laying on the floor above the 1/16" insulation supports.

These insulation wires were about the size I needed and ended up fitting almost perfectly in the gap.  I tacked the piece of wire in and then moved down to the other end of the transmission tunnel.

The gap was pretty large here.  I first made sure the floor was tight against the transmission crossmemeber flange and did those plug welds.   The edge of the floor at the gap was about 1/4" away from the transmission crossmember.  I used my 2" rotary air sander to clean up the surface of the crossmember flange and then pushed the floor against it and tack welded it.

After this I moved down to the middle of the trans tunnel.  Interestingly enough, the gap was almost nonexistent.  I put a couple of tack welds here to hold it in place.

I used the larger 1/8" rod to fill the gap that was immediately to the rear to the transmission crossmember.  One of the things I had to do was to move around and work the butt weld joint to match the changing contour of the transmission tunnel and to keep the heat from warping it.  A judicious blast of compressed air kept things cool.

Here's what it is looking like with most of the tack's in from the transmission crossmember to the rear corner of the new floor.

Once I knew I had the floor pretty much tacked in place where it wouldn't move, I decided to finish up the rear corner area to find out how this would eventually look after filling in the spaces between tacks and dressing up the welds. 

I do have to admit it turned out much better than I would have ever imagined.   I know it's only a floor, but I figure if I can get this to look good, I can make the rust repair in the deck lid and in the corner of the body by the deck lid look as good if not better.  

I started to finish the butt joint at the rear of the floor pan, but ran out of time.

At least the lion's share of the hard work has been done.  I have about half the plug welds to do on the frame rail and the gap to fill and weld between the trans crossmember and the front edge of the floor.  I have probably another couple of hours to finish the welding and dress them up to my satisfaction.   Then I'm ready for the seat riser installation.

I will say, I have to thank a host of you for your encouragement and ideas.   It has saved me a boat-load of time and money by not buying a new floor.   Do I hear voices saying, "I told you so!"?    I'm glad I listened. 

driver's side floor repair--If at first you don't succeed...Part 2

Car restoration could be like life and a deck of cards; you play with what you're dealt.   Alex and RJ have weighted in and my friend Glenn who helped me find the fastback have all agreed that the gaps aren't that bad and there are some work-arounds.   So that's the direction I'm going to go in and ditch getting a new floor.  Like Alex commented, "Metal is metal", right?

So here's what I'm going to try.  I have some small pieces of the floor leftover from trimming the edges with the air saw.  I'm going to experiment with the "Alex method" of using those pieces to fill the gap and then grind off the excess.  Then I"m going to try the "Glenn method" which is to take a piece of small diameter wire, like 1/16" or 3/32",  and tack that in place to fill the gap and then grind that flush to the floor.  I'll swing by Thrifty Supply on the way home and pick up a piece and then let the experiments begin.   I promise I'll document it all with photos for the next person with the same or similar issue. 

That's what I love about this blog and others.  Everyone gets to learn from each other and get support to carry on.  If it weren't for that, I'd probably be ordering a new front floor today.  

Thanks guys!  I appreciate your encouragement.

driver's side floor repair--If at first you don't succeed...

After a couple of weeks of "challenges" on the home and work front, I got some time to get back working on the fastback.  And since it had been awhile since I did the fit of the front floor, the holes for the plug welds and edges needed to be cleaned up again to get rid of any surface rust that may have started to form.  So I pulled the floor out and got it all shiny in the right places...

Then I moved on to clean up the edges of the floor, the firewall extension, and the frame rail surfaces.  I also got underneath and cleaned up the edges of the transmission tunnel and driver's side passenger floor pan....

Then I put the floor in and got ready to use my nifty Eastwood weld clamps to keep the floor in place.  I used these on the right front splash apron and they worked slick...

If you are going to do any butt welding of auto body panels, these are definitely worth the price of admission.  I put the floor in and started the clamping process at the seam where the back of the driver's floor met the front edge of the passenger floor.  Things looked pretty good....

The gap was near perfect and proceeded to install clamps moving toward the transmission tunnel, but the gap at the corner was not closing up.  The bend in the floor pan was not tight enough. 

So I undid the clamps and got out my trusty hammer and dolly and proceeded to get the radius tighter.  It took a few tries and clamping and unclamping and more hammer and dolly work before the floor pan was getting to where it needed to be.

I still wasn't happy with the fit.  After looking more closely at the joint along the transmission tunnel, I discovered the floor pan needed to have some more material removed and some more hammer and dolly work to match the contour.   It was starting to look good....

I started to put the rest of the clamps in.  But as I got closer to the front of the transmission tunnel near the crossmember, I noticed the gap was widening.  I could pull it closer, but then the floor wasn't flush against the transmission crossmember  or frame rails.

Not good.   I made sure the floor was flush to the frame rails and crossmember and started the clamping process all over again for the umteenth time.  It was at this point that I realized there was no way I could keep the floor flush and get the fit at the transmission tunnel without the lip at the inside of the rocker panel having a 1/8 inch gap.  I did some measuring and there is way too much gap to even attempt to weld the joint together...

This is the joint in the middle of the floor and transmission tunnel.  It's about an 1/8" of an inch which is twice the width it should have been.  Here's the joint at the back of the driver's floor pan to passenger floor pan joint.

It's a little wide at 3/32 of an inch.  Ideal is 1/16".   The gap that was tight here spread as I tried to massage the floor and transmission tunnel gaps.  This just isn't going to work.

So...after all the hours of work on this one panel, it looks like I'll be ordering another floor pan and starting all over again.  The only think I can think of that screwed this us is that when I was trimming the floor, I didn't get it flush with the frame rails and transmission crossmember.

Oh well...   If at first you don't succeed, try, try again.

Driver's side floor repair...getting the fit right

I set out today to make it as far as I could on getting this blinkity-blank driver's side floor in the car.  I didn't get started until around 10:30 AM which I will explain later.  Putting the floor in has had me in somewhat of a snit since in the Indianapolis area there are a number of specialized Mustang restore shops because it seems that each one has their own idea on how to put a floor in.  "The Mustang Ranch" is one of the oldest.  It's pretty much a one man show and the owner is not getting younger.  It's also hard to get in touch with him since he works his own hours and often when I swing by, he's not there.  Another shop is "Vail's Classic Autos" in Greenfield east of Indy.  They do Mustangs and other "high end" cars such as Hemi Mopars from the late 60's and early 70's.   They have a killer collection of Mustangs including a 69 Boss, a 68-1/2 Cobra Jet, a 66 GT convertible, and a 68 Shelby GT 500 KR....   You get the point.  I discussed the floor repair with one of their Mustang restorers, (who was working on a 70 Boss 429 buy the way).  He was a big fan of overlapping the floor pan by 1/2 in with the existing metal and welding both inside and outside.   So when I did the passenger side floor, I did it that way.  I thought, "Why not do it that way?  The shop turns out cars that make magazines and are show winners."   Then, about a year later, I came across Dave Scribling Restorations in Crawfordsville, Indiana.  If you don't know him, he did the famous 1968 Mustang fastback "Mustang in Black" that incorporated the engine, chassis, and electronics of  a 2003 Mustang Cobra into a relatively stock looking fastback. That was a major magazine car and a "mule" for his suspension kits he sells.  He was a proponent of butt welding the floor seams together.  So.....I decided to do that on the driver's side floor.  I don't know if one way is right or wrong. I'll end up with a larger seam to deal with on the passenger side, but figure I'll deal with the differences after I get the car on the rotisserie.  So onward....


I needed to make sure the floor was in contact with the frame rails.  I had a couple of cinder blocks that I used to weigh it down.   Then I took a look at the gaps and fit.   I laid underneath and marked the outline of the frame rails, transmission tunnel, and rear and front pan overlap.

I wasn't happy with the fit between the floor pan and the transmission tunnel crossmember not to mention the other gap along the transmission tunnel.

I decided to work on the transmission crossmember to floor pan fit first.  My plan was to make the radius of the floor pan match the crossmember.   Instead of using a rounded nose body hammer which would have left a ton of small dents, I made a buck from a 2"x4" and my multi-tool.

Then I used the buck and my 22 ounce hammer to "persuade" the radius into shape.

It did help, but not quite enough to get the contour right.   So I decided to go with a profile template to have a better idea of making the radius fit.

I used a piece of micro-corrugated and set the straight edge along the top of the flat section of the trans crossmember.  Then I traced the profile of the crossmember onto the cardboard.  I cut along the line and ended up with this template...

"F xc" marks this as the front transmission crossmember profile

I did the same thing for the rear edge of the crossmember....

This is the profile for the rear transmission crossmember

I marked two datum points on the templates.  One was the edge of the transmission tunnel where the original floor was cut away.  The other was the line marking the inner edge of the frame rail.  I looked through my dollies in my body tool box and discovered one that almost fit the contour exactly. This was the front template fit....

...and this is the rear template fit...

The difficult part was that working one contour changed the other slightly.  So, after multiple attempts at working both sections of the floor, I was getting close to a good contour on both sections of the floor pan.

I still needed to work the edge to get it to fit the transmission crossmember profile, but I also needed to trim the floor pan to fit.  I wanted the contours to be as close as possible so that I didn't end up short with material later after I trimmed it.   There were multiple...and I do mean multiple times... that the floor went in...and then came out for some more massaging...and went back in, etc, etc, etc.

This is after the first attempt.  Notice that there's still a gap, but part of the reason the gap was there was the extra material that will eventually be cut off for the butt weld along the trans tunnel hadn't been removed yet.

The fit along the rocker panel and on the frame rails was nice and tight.

I finally got the floor pan formed to match the contour of the crossmember as good as possible.

I then proceeded to trim the floor pan on the rear side and the transmission tunnel.  It took 3 trim sessions and a bunch of grinding with my 24 grit 2" air sander to get the gaps consistent, but the time and effort were well worth it.

Now it was on to drilling out the holes for the rosette welds.  I marked the outline of the trans crossmember and the frame rails.  I also marked the overlap line for the firewall extension.

Here's the finished result with all the holes cleaned up of burrs from the drill.   Here's the view of the fit from the passenger compartment...

...and this is the view from the engine compartment.

So, after 6 hours of work, I decided to call it a day.  I didn't want to start welding at 4 in the afternoon when I was tired and hungry.

Speaking of hungry, for all the time I was working on the Mustang, I was also babysitting my smoker.  The meat went on at 10 AM and I hit the garage shortly thereafter.  I loaded it up with a beef brisket, a whole chicken, a pork shoulder, and a rack of beef ribs...

The chicken was already done around 2 PM.  So I pulled it off and put the ribs on.   All the meat was done by the time I got everything put away in the garage around 5 PM.   So I would say I made some progress on a number of fronts.  Hey...a guys gotta eat, and it might as well be good eats.   Besides, restoring a Mustang is hard work as many of you know.   The difference for us is that the smoker is at my house!  I hope to get the start on welding in the floor sometime later this coming week.  I don't have anything on my agenda which is really strange, but as my life has often been, I'll make no predictions.  There's always hope though....

Driver's side floor repair...on to the actual floor

It's been a month of a week.  I'm sure some, if not many, of you know what I mean.   Lot's of stuff going on...some of it not pleasant, but it comes with the profession.  With a trip to Baldwin, Michigan to close up the family cabin, then heading southeast to Battle Creek for my niece's wedding, and sticking around to do my annual fall trip to help my mom with things around the house, I've had precious little time to prep for the trip.  Grass needed cutting, the yard trimmed, getting the dog kenneled, cars serviced and now packing, it's been non-stop.  I wore myself thin and took a nap to feel better. (Harvesting has started and the corn and soy bean dust is killing my sinuses.)  

I continued my packing getting all the tools and supplies I need to take north.  After moving the front floor pan out of the way to get to some other stuff, I thought, "Why not get started on that."  So I did.

First order of business was to clean up the cut on the floor itself.  I left the cut "rough" when I removed the old floor until I knew what I needed to get rid of.

I used a piece of steel for a straight edge and marked the line off.  Then I went at it with my air saw.  I love that  tool!   When I got done, I had this nice straight cut ready to be cleaned up for a good weld.

I lined up the floor with the inside of the rocker panel and used the existing spot weld marks as a guide to mark where I needed to drill my 5/16" holes.   This worked good since my weld and seam manual was rather sketchy on where the spot welds go. 

 

With the welds marked, I took the panel and center punched it for drilling....

 

Then came the fun task of drilling the holes.  I bought a really good DeWalt drill bit that is stepped with a build in pilot drill.  It is slick and saves a ton of time.   I used a piece of old deck board (remember that project?) as a backer and drilled out the holes.

Then I did a rough fit to see how it looks....

It's not too shabby, but I need to work on the transmission tunnel joint.  I was just glad to carve out a half hour to work on the car.   And the Eastwood fairy came by the house too with a quart of "Metal-to-Metal".   I'm already looking forward to the weekend of the 15th to do more extensive work.   The 15th?  Man that seems a long time away, but if it's like September, it will be here sooner than later.