Saturday, February 27, 2016

Floor Pan refurbishment - Why leave Good Enough alone?

Restoring an older car can be a slippery slope. What starts as a quick cleaning or part replacement can quickly turn into a much larger and more involved project. In Engineering, it's called "scope creep"; in restoration parlance, it's referred to as the "while-I'm-at-it" sickness. Whatever you call it, it'll eat more time and money and possibly open up more cans of worms than one may be comfortable with.

Now, that said, this isn't really a case of "while-I'm-at-it", but really just a long delayed chore that I'd put off because I thought it would suck, and it turned out to be worse than that. In fact, this is the most unpleasant task of the restoration so far.

The floors on old Mustangs are notorious for rusting out from cowl leaks under the dashboard, years of being driven on road salt, and old undercoatings that would trap moisture next to the metal. In my case, the floor had very little rot. In fact, I almost felt guilty showing it on the forums because so many folks have it much worse than I do. It's not so much that the floor isn't rotted out - it's more that it hasn't rotted out yet. Mine's not rusty, it's just really dirty. Shouldn't be too hard to clean the dirty off and make it nice, right?

I've already taken care of the backend of the floor pan and the interior side of the floor. All that's left now is the bottom of the cabin floor. It's about 40 square feet of metal that, if you're doing it right, never sees direct sunlight, and no one but tow truck drivers, mechanics, and car show attendees will ever see. So why bother messing with it at all, if 98% of the world will never know it's been done? Because when I see those pictures of perfectly restored floors out there in Interweb Land, it's makes me all weak in the knees. I want my hidden metal to look good too! Logic be gone, let's do some cleaning!

I'll cut to the chase - what my cleaning revealed was widespread minor surface rust. I needed to more than just clean this floor, I'd need to decide if I was going to either (1) remove the rust, and as a result,  put a new, proper coating over it, or, (2) just leave it alone after the cleaning and let it ride.

Also, keep in mind that I'm going to do this trick while on my back and the car's on jackstands, giving me about 18 inches of working clearance from floor to car. No room for a rotisserie in my garage, so the old school methods will have to do...

Before the project started, this was the view under the car. I've said it before, this car was covered in oil-rich muck and a thick layer of dirt and grime all over from a leaking power steering system and a leaking rear main seal in the engine.

Once the drivetrain was pulled out, it was easier to see just how messy this was. But, notice, no real rust to speak of! This is looking down the transmission tunnel from the firewall.

Here's the floor near the emergency brake connection point. 

Another view of the emergency brake connection point. 

Tunnel view, looking forward to engine bay. Most of the dirt was able to be cleaned off with a 1:1 mix of warm water and simple green. Unfortunately, it has to be cleaned off while I'm on my back and have about 18 inches of room to work. But the cleaning reveals the factory primer. This car is a very late '67 model built in San Jose, CA. While the other plants in New Jersey or Michigan would use 'slop paint' to prime the bottom of the car, San Jose cars were very consistently covered in various shades of red-oxide. This is sort of a pink-salmon color.

Finally, a clean floor! But look closely and you'll see the rust spots all over...

A closer shot shows the floor is covered in these rust spots, like freckles on a red-headed lifeguard. This is the real problem here. So, leave it alone, or fix it? Will it rust through if left alone? Would you want to wait and find out?

In several places the primer is just gone and has exposed bare metal...

And in some cases even more surface rust, here where the tires kick up road debris under the rocker panels. The factory blackout is also visible here.

While I've already shot the interior in red-oxide epoxy primer, the rear section was finished in black epoxy. I tried the red oxide under there first, and just didn't like it. My coating of choice is still the SPI epoxy primer (see link in 'resources' sidebar), but you'll notice the salmon-colored factory primer still on the floor pan doesn't really match the bright tone of the fresh red-oxide primer from SPI. So I want to use the black on the rest of the floor. I think...

Now, I struggled with this in my head quite a bit for weeks, maybe months. Was I making a mistake? I'm not doing a concours restoration, but - like they say - "it's only original once". By scraping and recoating over the factory primer, I'll lose that little bit of history on the car. You can still see all the drips and runs in the factory process. as well as the blackout paint on the edges of the floors.

In the end, I decided that it's my car, and my rules: I get to do what I want. And what I want is clean, smooth, new-looking metal, even if no one will ever look for it. I decided on a compromise - I'll record the neatly preserved features on the floor here for anyone who cares to look at, and then I'll slather new black epoxy primer all over the clean, rust free metal.

So, for the record:

Factory drips in the primer as it dried while moving down the assembly line.

Runs in the primer. This lets me forgive myself if I have any runs in my primer too, right?

Blackout trim at rocker over the floor primer, with a notch where tooling of some kind was in the way of the spray wand.

OK, so here's where we start stripping metal after cleaning...again, on my back, holding the angry grinder over my head and trying not to kick the jack stands out from under the car.

Masked and cleaned with Wax and Grease Remover..

First coat goes on nicely.

After the first coat of epoxy was on, I put seam sealer in all the right places (per the weld and sealant manual) and over some seams where I patched metal in the floor. Naturally, I forgot so take pics, but if you've ever caulked a shower, you have an idea of what this is like. Except you're on your back and the caulk has consistency of warm caramel.

The seam sealer is the NAPA in-house brand that can be used with a standard caulk gun, and is about $20/tube. If you want to move up to what the pro's use, those 2-part seam sealers are about $50/tube and you'll need a special gun for about $100 or more. I looked at this long and hard, and the consensus is this is the best 1-part sealer people are liking. Time will tell.

Apply the sealer about an hour after the first coat of primer, and let the sealer cure about an hour before shooting the second coat of primer.

Second coat is on, an it's everything I wanted it to be.

I love it, and have no regrets about doing it. I know the rust is gone, and even though it's not factory-correct, I love the look of the black epoxy primer. Some folks will follow this step with an undercoating of some kind, but I'm not sure I want to do that just yet. If I do, it'll only be down the rocker panels where they're likely to get chewed up by road grit.

It took me over 50 hours of work to get this done, spread out over almost a year ('cause, like I said, this job just suuucks...)

So, lessons learned:
1. Remember whose car this is. If it's yours, and you're not doing the concours thing, you get to do what you want. You want to paint Shelby stripes on the floor? Go for it.
2. A rotisserie would make this job a lot easier, but it can be done without it. But next time, you better believe I'll buy/rent/steal one for this step.
3. This is an unpleasant process, but the end result it totally worth it. I would suggest just doing the whole thing in one long weekend instead of dragging it out for months like I did.
4. Seam sealer selection is hard. In the end, it comes down to how much you really want to spend on what is essentially glorified bathroom caulking. In my case, it was $20.

Thursday, February 25, 2016

Adding a Torque Box

This is probably the first "modification" in the project that's not strictly by-the-book. I'm going to add a torque box to the passenger side of the car, even though Ford didn't do it back in The Day. Two good reasons to do this. One, because it's a great way to make the chassis stronger - and two, it's a fun excuse to say "torque box" over and over.

A torque box is a chassis strengthening component that ties the frame rail to the outer rocker panel. Basically it's just a triangular box that keeps those two pieces from moving independent of each other.

The early model 65-66 convertiles got two, one on each side, coupes and fastbacks got none. In '67, fastbacks and coupes got one on the drivers side. The 1968 Mustangs were the first year to get torque boxes on both sides for all body styles. Up till then, only the convertibles got both of them. Ford should've done this in the first place, but I assume it was a cost-cutting measure to leave it off the fastbacks and coupes for as long as they did.

The beauty of this is that the '68 chassis are the same as the '67, so it should fit just fine. Except that almost everyone who makes this upgrade reports having to really struggle with fitting the new metal because after years of flexing, abuse, use, and general entropy, there's a little slop in the chassis interfaces where the torque box gets installed. There's always one guy who says his torque box just "dropped right in", but that's the exception. I'd say prepare for a fight.

Free advice: get the two-piece box. Yes, it costs more, but it fits better and makes installation easier. This whole effort (prep, prime, fit, weld) took about 20 hours over the course of a week of stay-cation at home.

Here's the torque box on the drivers side, installed at the factory during the Johnson Administration:

Here's where the torque box will live on the passenger side, bridging the gap between the outer rocker panel (left) and the frame rail/floor support (right). Don't be distracted by that ugly patch in the toeboard - it's a good butt weld that I didn't obsessively clean up as part of my anti-OCD therapy. The car is still up on the jig, with supplemental jack-stands for "just in case".

First thing is to remove the little brace inside that ties the toeboard to the outer rocker panel. 6 spot welds hold it in.

I needed to cut a slit in the toe board to get the inner part of the new torque box to fit in the proper place. The slit is a little wider than I would have liked, but seam sealer on the inside will fill the gap. 

Primed all soon-to-be hidden surfaces, while keeping welding locations in clean bare metal. I've officially given up on using weld primer as all it does is contaminate my welds and make them less pretty. I noticed the clean metal welds are smoother without it. So my new strategy since the frame rail repair is to prime near, but not on, the actual plug welds.

"This is my torque box. There are many like it, but this one is mine." The piece on the right (inner) butts up the to the toeboard and provides mating surfaces for the (outer) piece on the left. This is the more expensive version, about $75, but it's a solid piece of well-formed 14 gauge metal. I scuffed the e-coat and shot some epoxy primer on it before installation.

Inner piece fit in place and welded in. 

The outer piece here shows where all the welds will be holding it in - along the top, sides and bottom, plus some bead welds along the floor support and frame rail, all per the weld & sealant manual.

The outer piece needed a LOT of persuasion, both clamp and hydraulic, to get it properly placed. 

Here's the back of the box at the floor support.

This is the interface between the outer piece and the bottom of the rocker panel. Super critical to get good penetration here. Since the inboard part of the torque box has so many more welds, it's easier to get it good and tight there. But since the outboard side has so few welds, this is where the action is.

And here's the finished product. Seam sealer will be used along the top at the outer toeboard interface and the inside gaps as well. It's obvious now how much this helps tie the front end structure together, but I wanted to make darn sure the car was square before installing this. That's why this piece as installed after the frame rail/floor support.

There are still some small details to clean up on the front end before it's "done", but this was the last big piece I'd planned on doing up front. I still need to install some braces in the lower shock tower pockets and do the Arning Drop for the new passenger side shock tower. 

Remember how to eat an elephant: one bite at a time...

Wednesday, February 24, 2016

Radiator support removal and replacement

On to the radiator support...

The radiator support, or "rad support" for short, is the forward-most piece of the Mustang chassis. It's purpose is to hold the radiator and provide something for the hood to rest on, as well as box in the front engine bay. It's connected to the front of the forward aprons on both sides and the front crossmember at the bottom. Good reproductions are out there, and are available attached to a new crossmember as well - which is the piece I purchased for my car.

About 80 spot welds and a dozen or so bead welds are holding this assembly in place. It took me about 25 hours to remove, prep, patch, install, test-fit, and weld in the new assembly over the course of about a week. Overall, I would call this 'much easier' to do than the frame rail assembly.

First, let's look at what we're starting with - way back before any metal work had happened...

The radiator support and crossmember are bent, rusted, crinkled, and in generally poor shape. 

The backside view shows more of the issues. While some wrinkling can be taken care of with judicious use of hammer and dolly, there were so many issues here that I figured it would be easier to replace it. Also, I should mention, this was supposed to be my first 'real' on-car welding since I didn't have any other issues. Of course, I then proceeded to discover no less than five other sites that would need welding as well. I was so optimistic back then...

Look closely and you'll see the crack in the rad support/crossmember interface here. Likely due to collision damage and subsequent frame straightening.

So this is where we left off - the new shock tower/frame rail assembly welded in place. I had to cut out chunks of the rad support to get the new assembly in place, so now it's time to cut the rest out and get the new one in.

Here's all the spot welds drilled out at the drivers side front apron interface. I drilled them all the way through so I won't have to  drill a bunch of holes in the new piece - I'll just weld the new part on from the backside. Should be easier and a make for a cleaner finished product. New rad support on the wall, just looking for a new home!

Next up, removal of the rest of the crossmember. No need for finesse here, just hack out the big pieces with a whiz wheel... 

...and clean up the mating pieces by locating and drilling out the spot welds holding it all together... that there's a nice, clean surface to weld the new assembly to. Easy as cake.

Repeat this process for the crossmember remnants on the strut rod mounts. Please notice that the passenger side strut mount will not actually ever leave the car, but will always be attached by at least one end at all times. To me, this is cool.

Clean, shiny metal, ready for welding. 

The new forward apron needs all those new holes drilled for plug welding. I'll say it again - get a factory weld and sealant manual for guidance here. It's just easier. Otherwise, one may tend to 'over-weld' everything and put 20 welds on where the factory only used 11.

Oh, yeah, baby! New metal! Note the optional integrated crossmember here. Same as the other pieces, drill in preparation for plug welding at the frame rail interfaces. The apron interfaces are stripped of e-coating once I test fit everything and mark the adjacent hole locations on this part.

For comparison, here's the old part.

Oh yeah, there's a dozen welds on the inside as well... a few underneath. If you haven't practiced inverted plug welds yet, now's a good time.

I noticed a rusted and cracked divot on one of the strut rod mounts. It's just easier to cut it out and replace it than it would be to bang it back into shape.

Newly fabricated patch is welded in place...

And the welds are cleaned up to it looks like it's supposed to be there. No one will ever know this was done, but I get a kick out of this sort of thing.

Test fitting is done by clamping and screwing the pieces together, then placing the hood and fenders to make sure the parts line up. I takes an hour or so, but now's the time to find out if it's in it's proper place or not.

Here's the backside plug welding on the drivers side apron.

Strut rod supports are welded in with a combination of plug and bead welds

More of the same welds on the top as well. All per the factory manual.

Some Seams are Strategically Stitched , Strictly Speaking. This one is an inside corner. I would add this one even if it wasn't in the manual. A little extra strength up here is a good thing.

And there it is, all burned in and ready for another half-century of supporting radiators. 

Next up - adding a torque box where God intended, but Ford was too cheap to listen.