Finally found a 69 240z, #51 Time to finish a 30 year multiple owner restoration.

[HS30-H]

6 hours ago, Captain Obvious said:

Not sure I understand this part... Why would the complexity of the joint mandate lead loading? I get that a complicated joint like that would require "some sort" of loading, but why specifically lead? Couldn't they have used polyester filler instead of lead?

In other words, is there something mechanically different about using lead here instead of a plastic filler?

I'd say that the complexity of the joints (shape, and number, of the panels being joined) meant that they were likely to be - as we have seen in the 'nude' shots - 'cosmetically challenged'. Add a little assembly worker variation into the mix for good measure. They required filling/smoothing, and the top of the rear quarter joint was a large area. I can't think of any other areas of the early S30-series Zs where cosmetic filling was required before paint, as I pointed out up-thread. Can anyone think of any?

This is specifically a Nissan Shatai thing. If it was their habit to use lead, and they had workers who were skilled at applying it well, and fast, then why not? It certainly 'dries' and is workable much faster than a plastic-based filler and there's no use-it-or-lose-it time constraint as there is with a hardener-added mix. Much better for a busy production line. And as we know, the lead is very resistant to cracking. Seems ideal.  

[dspillman]

3 hours ago, HS30-H said:

I can't think of any other areas of the early S30-series Zs where cosmetic filling was required before paint, as I pointed out up-thread. Can anyone think of any?

This is specifically a Nissan Shatai thing.  It certainly 'dries' and is workable much faster than a plastic-based filler and there's no use-it-or-lose-it time constraint as there is with a hardener-added mix. Much better for a busy production line. And as we know, the lead is very resistant to cracking. Seems ideal.  

      The base of windsheild frame/cowl area appears to hold much more lead then hatch area….

[Captain Obvious]

3 hours ago, HS30-H said:

This is specifically a Nissan Shatai thing. If it was their habit to use lead, and they had workers who were skilled at applying it well, and fast, then why not? It certainly 'dries' and is workable much faster than a plastic-based filler and there's no use-it-or-lose-it time constraint as there is with a hardener-added mix. Much better for a busy production line.

Got it. I'm not a body guy, and I thought you were saying the joint mandated lead (specifically). It does not require lead... It requires a filler, and they chose lead.

Thanks.  

[Patcon]

I suspect lead is more forgiving of movement too. I think the move away from lead was because of the health hazards and the skill needed to get it on properly. Plastic filler gets more brittle with age but lead does not. Lead is also very maleable.

Lead was a great additive for paint too, but was done away with for health reasons too. Sometimes the cons outweigh the pros...

[dspillman]

On 4/26/2024 at 1:29 PM, Zed Head said:

The puddle of lead is interesting but can you dig in to the actual joint itself to see how the two pieces are attached to each other? 

  Attached via stitch weld for sure, then “hidden” with the lead filler spread over and smoothed.  Properly shaped wooden paddles for the front and rear, and the self leveling tendencies of molten lead, smooth and flexible.

 Pulled apart the interior side of panel junction at corner of rear roof area…. 6 panels held in place/reinforced by a “t-plate” of sorts…. All spot welds in this area.

Edited April 28 by dspillman

[Patcon]

Yes, there is a lot going on right there. One of the main issues is similar at the rockers. To work on the inner pieces properly you have to "peel the onion" and take the overlapping panels out of the way. Increasing the work dramatically! That's alot of spot weld drilling to even get a fairly small panel off.

[Namerow]

4 hours ago, dspillman said:

Pulled apart the interior side of panel junction at corner of rear roof area…. 6 panels held in place/reinforced by a “t-plate” of sorts…. All spot welds in this area.

Nice photo essay.  Well done. 

If you or anyone else has the opportunity, a similar presentation for the rocker panel area would be a great assist for other restorers.

Edited April 29 by Namerow

[Zed Head]

Thanks for doing all of that work and showing it.  People that do restoration probably don't realize how much hidden rust there is in those cavities and seams.  

I'm still curious about what type of welding/brazing/soldering they were using to attach the pieces.  The seam where the roof panel meets the C pillar outer skin looks like it's an overlap of formed sheet ends, the C pillar end going under the roof panel piece.  So there's an area that might typically be brazed, with filler metal flowing in to the gap.  But it also looks like some welding is going on between the two base metals.  The distinction between welding and brazing seems to be whether or not the metal of the two pieces being connected melts or not.  In brazing it doesn't and it's adhesion between two different metals.  In welding the metals all melt and form a new alloy, a melt puddle, at the junction.  The quality of the work reminds me of what my friend did when he brazed an exhaust system together on one of my old hot rods.  A torch (flame) and some filler wire.  Ugly but effective.

Any chance you can show the seam along the drip rail?  that's where the roof panel would be attached.  I assume that it's a string of those "booger" beads.

[dspillman]

1 hour ago, Zed Head said:

Thanks for doing I'm  But it also looks like some welding is going on between the two 

Any chance you can show the seam along the drip rail?  that's where the roof panel would be attached.  I assume that it's a string of those "booger" beads.

No “booger beads” up the drip rail…… spot welds from the lead filler and foward.

     Couple of quick pictures with naked drip rails….. One car has obviously been aggressively sand blasted to the point of removing the lead in the process. “ it was purchased this way”.  
    Gray car with lead still in place, and visible where the joint is and the feathering of the lead smooth each direction.

   Orange car can also just make out where the lead sits, and where spot welds in the drip rail  

 

 

begin foward of the lead cosmetic patch.

[dspillman]

Pulled doors/hinges today from the body, doors are quite nice, original door passenger side will need some repair, but shouldn’t be that difficult to repair……   Hinge attachment point at body is in great shape on both sides.

   Have plenty of help from 3 of the grandkids!!!

[Patcon]

Love the helpers!

My first was born about 6 weeks ago. I'm looking forward to shop time with him in a few years!

You have the early style door hinges. They can be hard to repair and hard to find. You're missing the spring on at least one of them...

[dspillman]

25 minutes ago, Patcon said:

Love the helpers!

My first was born about 6 weeks ago. I'm looking forward to shop time with him in a few years!

You have the early style door hinges. They can be hard to repair and hard to find. You're missing the spring on at least one of them...

     I need to study a bit on the hinges….. I’m thinking the early had smaller coil spring?