Monday, February 28, 2011

fixin' up the firewall

So the original intention with the passenger compartment (or interior if you prefer) was to start by lowering the seat platforms, and then go over all the surface rust with the wire wheel before painting the entire area with epoxy primer. But as usual on this project, things didn't really work out according to plan. For a start, I found that constantly opening and closing the doors was too much hassle, so I took them off...and then got sidetracked into stripping the paint etc.

Then, after starting to work on the rear portion, I found a lot more surface rust than I was expecting, and the grinding began to drag on...eventually I started to worry about leaving the bare metal exposed too long. It's a difficult one, because the climate in the Bay Area, especially this year, is really mild - I don't think the temperature has dropped below 65 F in all of January, and humidity levels are really low....but then nothing stops rust like a coat of epoxy primer, so in the end I paused in the grinding process and sprayed primer at the rear.

The front of the interior was much more complicated than the rear: all the dash to work around, the inside of the upper A-pillars to clean up, and then of course there were the repairs I needed to make to the sheet metal. I took out the ugly 70's aftermarket ac back in May 2010, but at the time I didn't realize how much damage the PO or installer had done to the firewall and the passenger side foot-well. Here's a shot of the firewall from before the ac or heater was removed - apart from the horrific overuse of caulking, it doesn't look too bad.

However, after I removed the heater and ac hoses, I could see there was some distinct damage to the firewall.

Here's the view from the inside of the car before I scraped of the caulking:

There were also several holes in the passenger foot-well, and in the transmission tunnel.

Once I got rid of all the caulking, it was good news: although the firewall has been cut, the hose opening has been enlarged by bending the extra metal upwards and out of the way - bending this back into place and welding up was a much less frightening prospect than fabricating a replacement piece.

I started out by grinding the paint of the inside of the firewall with my wire wheel, which made it all look much better.

The next step was to bend the metal back into place, which I achieved with a pair of pliers (!) followed by hammer and dolly work - the heater hole was just big enough for me to reach a couple of fingers inside and hold the dolly while I stood in the engine compartment; this would have been much more difficult, if not impossible, with the engine still in place. I was able to get the metal close to where it should be by this method.

I clamped a 1/4 inch piece of copper across the join - this serves a dual purpose since it holds the firewall straight and also acts as a heat sink for the welds.

I put the first welds down on the inside, and then did a little bit more work with the hammer and dolly to straighten up the edges of the firewall openings. The copper heat sink was then clamped on the inside, and additional welds added at the engine compartment side.


This is the view after the welds were cleaned up. A proper cleanup of the firewall and the rest of the engine compartment will have to wait for another day.

The ac installer also left three holes in the passenger side floor pan, where the system was vented. I think the smallest hole (arrowed below) was probably a mistake or a test hole as it was not actually used.

Starting with the hole in the transmission tunnel, I cut a small piece of 20 gauge steel and held it underneath the hole so I could trace the exact shape with a sharpie - I was just able to squeeze my arm though the shifter opening in order to do this.

After trimming with some snips I had a octagon-shaped patch while I filed down until it was a very close fit with the hole.

Here is the patch being held in place by a piece of masking tape on the underside. I was just able to reach to hold the copper heat sink under the patch while I welded it up with the MIG.

The first patch after cleanup

The other two holes were too far away to reach to from inside the car, so I stuck a piece of masking tape underneath and colored in the holes with my sharpie. I then used this pattern to cut out patches from the steel sheet. The smaller hole needed a bit of filing first to make it closer to a circle; I also had to bend the patches slightly to fit the contours of the floor.

This time I had to tape the heat sink to the underside before I welded up the patches.

The inside after cleaning up with the die grinder:

A little bit of cleaning up was also needed on the underside to get everything nice and smooth, and then I called it a day.

Saturday, February 19, 2011

more on the doors

Time to paint the doors and the rear valance...well sort of...I wasn't actually sure whether I should work on the body filler first, and then paint, or apply the filler later over the top of the epoxy primer? I searched around on the net, and VMF, and even posted a thread on the latter, and all that left me as confused as ever. This is obviously a question on which every restorer has an opinion...and they're all different! So I did what I always do when I'm stuck with something on my car: I turned to the guys in BAMA for help - after all, this is why I joined the club in the first place.

Initially I wanted to prime the doors now, and get stuck in to the body filler some time in the future, but I was convinced to rethink this strategy. The informed opinion is that filler definitely bonds best to metal, and rough metal at that. While applying a very thin skim coat of filler over the top of epoxy primer is considered OK, on the basis that most of it will be sanded off, major repairs should be done before painting. The damage to the front edge of my passenger door was most certainly in the "major" category, so I broke out the bondo! Incidentally, if you're facing the same dilemma, a couple of articles worth checking out are Using Body Filler, by Read Overson, or this one from, where the author does some actual experiments (note: the validity of these experiments has been questioned in terms of preparation of the metal although they look alright to me).

But hold on, before I could get to the filler, there was one other thing to take care of: the rust on the front edges where the hinges connect to the door. Not a huge problem, but one that couldn't be ignored either.

This seemed like a perfect opportunity to try out some Naval Jelly rust dissolver - I got this from my local ACE on the recommendation of a mate who uses it to clean rust off of garden tools.

I have to say that I was surprised at how well it worked. It takes a lot of water to wash off the residue, and my guess is that it would not be as effective on heavily corroded metal, but on this occasion it got top marks. Here's the "after" picture:

So, on with the filler. The passenger door actually has an interesting history. It originally came from a springtime yellow '67 car, and during its time on this vehicle it took a severe knock at the upper front edge. It's possible that whatever caused this damage was serious enough that the car was scrapped...and the door salvaged before being transferred to my car and given one of the most awful red paint jobs ever witnessed. So, to recap, this was the damage to the door after I removed the old filler and paint.

After mixing up some filler, applying it to the door and waiting about 20 minutes, I was ready to sand. The first objective was to establish a straight line at the apex, which I achieved with a rigid flat block and some 80 grit sandpaper.

And then I was stuck, as I couldn't really go much further with just a flat I sought out some more help, and my buddy Chuck came to the rescue with a curved sanding block and a roll of self-adhesive 80 grit paper. He also gave me a valuable lesson in sanding: always work in a diagonal fashion across the repair, then change direction so you in an "X" pattern.

The door kept moving around on my bench so I improvised a locking system:

After about 20 minutes sanding I was very close... I mixed up some glazing putty and spread in over the repair area.

After waiting for the putty to dry I finished up the sanding. The repair isn't perfect, but it is as good as I can get at this stage - I will no doubt return to this area later on when the door is back on the car and aligned correctly with the fender etc.

So ready to paint now? Well I was thinking so, but then I noticed a very small spot of rust at the lower front corner - I had actually spotted this damage before, but inexplicably forgotten about it (!) I did consider leaving it, or dabbing on some Zero Rust, but the thought of the rust poking through my paint job in a few years time was enough to frighten the life out of me!

The first step was to get rid of the rust with a very small grinding tip on the end of the Dremmel. This left four small holes in the outer skin on the door.

I used a tiny brush to paint Zero Rust inside the holes and then filled them with the MIG.

Ground down the welds so they were very slightly shallow...

...and covered the repair with some glazing putty.

After sanding smooth with some 120 grit paper I was finally ready to prime the doors.

Sunday, February 13, 2011

passenger compartment part three

At the end of part two of this series I was almost done with the wire wheeling in the rear of the inside...or so I thought. I did eventually get the rest of the surface rust off in one session, but it took a lot longer than I planned. I started off above the rear window, where there was a ton of crud to remove:

The C-pillars were in better shape, with rust restricted to the edges of the openings, but I just took all the paint off anyway as there's nothing like completeness.

I found I couldn't fit my angle grinder or die grinder into the tight corners, so I dealt with these areas by using a stiff wire brush dipped in lacquer thinner.

Before the wire brush had it's way

Lastly I cleaned up the package tray - there was actually very little rust in this area, so I could have probably left the original finish, but the perfectionist in me felt the need to expose the bare metal.

Before I could do any masking around the rear window I had to scrape off all the old sealant - I should have done this months ago, but couldn't find the motivation. This task took a good long time, mainly using a rag soaked in lacquer thinner and a small piece of plastic bondo spreader where the gunk was the thickest.

Not perfect, but good enough

And here's how the lower channel came out

So with all that grinding done, the car was looking like this:

Next I gave the entire area a really good going over with a the usual rag soaked in lacquer thinner, until all the surface dirt and grit was removed, and then sanded by hand with some 120 grit paper, and then repeated the lacquer thinner wash down (tedium at it's peak!)

Clean and shinny and ready for primer!

Finally time to start masking! I've said before in this blog that I love masking my car, and I freely admit that the amount of tape I use is excessive to say the least...but it's so much fun! I started around the back window opening with some low-tack decorators tape.

Then I applied strips of 1.5 inch masking tape to make a grid, with the sticky side facing inwards (or towards the side where the paint will be sprayed).

Same in the door opening, although I left a small gap so I could squeeze myself and my paint gun inside the car!

To finish off I pressed pieces of masking paper against the tape from the inside, and used more tape to cover gaps at the edges and joins in the paper. 


I left a little bit of the trunk area exposed so I can overlap with the primer from last time. The previously primed bodywork was scuffed with a Scotchbrite before I did the clean up. I also taped over all the small holes in the floor pan etc, from the underside.

Finally I put my trusty car cover over the top, just leaving a small access opening at the front of the door, and spread the usual dust sheets on the floor and over all the other gear in the garage....then it was time to get out the paint gun.

Here's the finished look after two coats of PPG red oxide epoxy primmer:

I had a bit of primer left at the end, so I gave the rear half of the roof a quick going over; there wasn't really much benefit in this as I already painted the underside of the roof with Zero Rust, but at least I covered up the worst of the brush marks...not that anyone will ever see this area.