3 hours ago, HS30-H said:

The lead-loading is not the fixing method of the panels.

Gotcha. So what is the fixing method? Are there spot welds that do the mechanical joining?

I (thankfully?) haven't been in that deep into the body.

Just for reference.

2 hours ago, Zed Head said:

More context might help here.  Were you looking at the area of the joint on a real car?  Why was Mr. Matsuo there?  How many people were involved in the discussion?  Who asked the question, and why?  Was the part about the windshield popping out secondary conjecture from somebody else or words straight from Mr. Matsuo?

Sorry, that's just how my brain works.  More questions.

  I don't recall if we (Charles and I, G-Nose Z may have been there too) were looking at a specific car at the time. Matsuo-San was at the Atlanta Z-Con because he was the guest of honor. The words were from Matsuo-San and we were specifically discussing the C-pillar joint. We did discuss body flex and twist. I don't recall him saying that it did pop out during testing but considering what these cars were going to go through during rallies, a large semi-rigid C-pillar joint made more sense than a stiff or semi-rigid A-pillar.

2 hours ago, Zed Head said:

More context might help here.  Were you looking at the area of the joint on a real car?  Why was Mr. Matsuo there?  How many people were involved in the discussion?  Who asked the question, and why?  Was the part about the windshield popping out secondary conjecture from somebody else or words straight from Mr. Matsuo?

Sorry, that's just how my brain works.  More questions.

  I don't recall if we (Charles and I, G-Nose Z may have been there too) were looking at a specific car at the time. Matsuo-San was at the Atlanta Z-Con because he was the guest of honor. The words were from Matsuo-San and we were specifically discussing the C-pillar joint. We did discuss body flex and twist. I don't recall him saying that it did pop out during testing but considering what these cars were going to go through during rallies, a large semi-rigid C-pillar joint made more sense than a stiff or semi-rigid A-pillar.

5 hours ago, Zed Head said:

More context might help here.  Were you looking at the area of the joint on a real car?  Why was Mr. Matsuo there?  How many people were involved in the discussion?  Who asked the question, and why?  Was the part about the windshield popping out secondary conjecture from somebody else or words straight from Mr. Matsuo?

Sorry, that's just how my brain works.  More questions.

We were at the car show at Zcon. I believe @gnosez posed the question. He asked about the lead at the quarter to roof joint. Matsuo San was a guest speaker and ViP at that Zcon. He said it was to let the car "breathe". We suggested "flex" and he agreed. He said if the car couldn't flex there it would flex at the windshield. He implied that the A pillar could break or the windshield could come out.

As an aside I read all 100+ comments in that BaT thread. Was really fascinating. I suspected that was TonyD stirring the pot. I also found it interesting that many commenters suggested that Japanese classics would never be worth what you put into them for restoration. I suspect if you had suggested that a 240Z would sell for $300k+ you would have been laughed out of the space. It was also interesting that nobody seemed to understand the uniquity of the very early cars. So much for the experts...

12 hours ago, Captain Obvious said:

Gotcha. So what is the fixing method? Are there spot welds that do the mechanical joining?

I (thankfully?) haven't been in that deep into the body.

In my experience, the joints were usually spotwelded.

However, I have seen a couple of bodies that had brazed joints (perhaps even spotwelded AND brazed).

13 hours ago, Mark Maras said:

The words were from Matsuo-San and we were specifically discussing the C-pillar joint. We did discuss body flex and twist. I don't recall him saying that it did pop out during testing but considering what these cars were going to go through during rallies, a large semi-rigid C-pillar joint made more sense than a stiff or semi-rigid A-pillar.

To digress sightly from the thread's main subject (sorry OP), here's an example of what the cars were going through on rallies:

English team Withers Of Winsford entered an ex-Works Fairlady Z-emblemed Datsun 240Z rally car - wearing the personalised UK license plate 'CAL 1' of company owner Mr Cal Withers - in the 1973 TAP Rally of Portugal, driven by hotshoe Englishman Chris Sclater and navigated by Dutch specialist Bob De Jong.

The service crew were forced to repair the screen pillar joints - which were parting company - mid-event, assisted by the staff of Portuguese Datsun distributors Entreposto. They took the screen out and either brazed or gas-welded the pillars back together...

 

At that point the car had already taken part in the 1972 Acropolis Rally in Greece and the 1972 RAC Rally in the UK. Perhaps not surprising that the bodyshell was starting to get a little bit 'baggy'...

 

 

 

 

6 hours ago, HS30-H said:

In my experience, the joints were usually spotwelded.

However, I have seen a couple of bodies that had brazed joints (perhaps even spotwelded AND brazed).

Got it. So it sounds like choices to fill that large visible joint after welding was either lead or plastic filler? And they chose the lead.

7 hours ago, HS30-H said:

To digress sightly from the thread's main subject (sorry OP), here's an example of what the cars were going through on rallies:The service crew were forced to repair the screen pillar joints - which were parting company - mid-event, assisted by the staff of Portuguese Datsun distributors Entreposto. They took the screen out and either brazed or gas-welded the pillars back together...

  No apologies needed. Those are incredible pictures showing the  ingenuity needed at the track to continue…… appears that roof had to be pressed back down to the body.

  Those 2 C pillow and window joints were truly put thru hell, with the twisting forces thrown at the car during roads/ditches and uneven surfaces in general.

      

 

 

 

 

On 4/23/2024 at 10:51 PM, HS30-H said:

The lead-loading is cosmetic. It covers what would otherwise be unsightly joints and is intended to be (slightly) resistant to flexing, but it is not the fixing method of the panels.

That makes sense. 

Does anyone have a picture of how the roof and rear quarter panels come together when the latter is replaced.  Failing that, maybe just a detail shot of the relevant area of the rear quarter panel.  There has to be a weld somewhere!