Great work on the roof patch. Looks like your roof is much like mine, probably less rusty. Mine has surface rust hiding between the frame and skin too, I was lucky enough to get my hands on a spare replacement skin in decent enough condition.
Hahahaha it’s such a silly mistake, and once you make it you’re like “how could I have been so dumb!?” I guarantee neither of us will make that mistake again...
Chapter 9 - Roofus Interruptus
Last chapter we went in fast forward to cover the half-done rear hatch, and the fully done front guards. This chapter, I want to cover an area that I have been too afraid to do since the beginning - the upper corner of the windscreen and roof.
Why have I been too afraid to tackle this? Well, when I took the sunroof out (yep - I've got one of those...) I noticed that the roof itself was paper thin! Welding onto this was going to be nigh impossible, and unfortunately I had a repair to do...
However, I thought my skills had improved enough to give this a fairly solid crack. The question was around what technique was I going to use??
Looking at this part of the roof section, there are angles going in every dimension:
The part that the windscreen rubber attaches to gently arcs downward.
The next, horizontal part, got marginally thinner and also gently arched backwards, but forward again right at the corner.
The top corner also gently arc's backwards, but also slightly downwards.
The roof skin bit also changed its shallowness the closer to the edge it got.
And, this was super visible, so getting it wrong would make Zee look like Frankensteiness.
Once again, after assuming foetal position again for a while, I figured I should be able to create the patch without needing to cut into the roof. This was perfect, because it allowed me to have several attempts at the patch if I needed to, which took that part out of the "how to stuff up your car" equation.
I used what I call "the Fitze method". Rather than trying to bend the piece in all of those dimensions (I just don't have that kind of skill ... yet), I decided it would be easier to make it out of 3 pieces - 1 for bottom, one of the vertical part, and one for the top. I started with the bottom, making a piece that slotted in perfectly over the existing spot-welded piece. I clamped it in place. Next was the vertical piece. I massaged it with a flap disk until it perfectly mated with the bottom bit, and then flexed it backward so it fit perfectly with the existing roof. This piece extends way past the roofline, but that is fine. I then created the roof patch, which I painstaking mated perfectly with the horizontal piece, and also clamped it in place.
Like a diamond in the rough, it looked ugly but had the right angles to work with. I tacked it with the welder in many places (while clamped), then pulled it off and welded all of the corners a la Fitze method, and ground them back to the shape I wanted.
The top edge is currently way to sharp, but its easier to make blunt than it is to sharpen...
Next step was to cut the roof. I didn't need to go back very far, maybe 3/4 of an inch, but wanted to go along far enough that I had good metal to work with. Once that was done, I took a photo, then nuked the insides with S50 Cavity Wax (I'd run out of Eastwood Internal Frame Coating).
Post nuke. That cavity wax gets into everywhere!!
Once done, it was time to cut back my patch, then carefully massage it until it slotted in perfectly flush.
Welding was done very slowly. Literally 2 spots at a time, then let cool until I could hold my hand on it. Then another 2 spots. I kept doing that until complete, then just as carefully flapped back the welds and dressed with anti-ox to stop from surface rusting.
I think it came up well, and I was super proud of myself! I even "showed it off" to the Aussie Z facebook group.
Front all finished (except for the corner welds which need cleaning up)
Its at that point that Lurch noticed the high amount of surface rust under the roof skin, and strongly suggested I take the roof skin off. I spent a day in complete denial, and then relented because he was right - unless I deal with the cancer lurking under the roof skin, its just going to come back again.
At which point, I enthusiastically moved onto the battery tray area!
While that is the truth (the part about moving onto the battery tray), I'm actually procrastinating on the roof. I will do it, but I need to decide whether I want to keep the sunroof or not. If I don't want to keep the sunroof, then I have 2 choices:
See if I can source another roof skin off a good quality parts car. (unlikely??)
Create a patch for the sunroof hole, and bond it in place. (its way too thin to weld, and metal bonding is meant to be just as good these days).
Or, I embrace the 70's, grow a mow, wear some vinyl, and keep the sunroof. Arg. Decisions decisions...
So, next chapter my son and I get the Engine and Gearbox out (making the exact same mistake as Ryan did with the engine leveler) and then I find more rust with the added challenge that its kinda hard to get at.
Nils from https://jdmjunkies.ch/ pinged me a link to this document this morning which was the press release at the time of the 240z launch in Australia. The user which uploaded it (https://www.flickr.com/photos/aussiefordadverts/), hasn't made it downloadable for now. Are you on here?
Note the launch date was October 1970 in Australia. Compliance date on HS30 00150 is 11/70 for comparison.
I thought it would be of interest to folks here.