They Said It Can't Be Done...Or Don't Even Try

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whitepunkonnitro said:
It looks good...but I'm one of the guys who recommended he not go this far with this car. Here's why...and PLEASE, I don't mean to be a downer or piss on anybody's parade. I'll just pass this on to anybody who might be considering this sort of reconstruction.
These cars are spot welded together at the factory. The design of the panel and their support is predicated on that sort of welding. When you cut a car apart like this and weld it back together with anything but spots or TIG, the welded seams are much harder than the metal surrounding them. When changing a quarter, or a floor pan, it's not a big deal. But, the roof structure is an active part of this cars chassis. If you've ever cut the roof off a hardtop and tried to lift the car, you'd see just how much rigidity the roof adds. As this car rides over bumps, and goes through cornering and stopping motions, the soft original metal will want to move slightly as it was intended...the hard seams will not. It's just a short time before those areas become work hardened and begin to crack. In the event of a serious accident, the metal will tear like tissue paper along the seams. There's a lot to this!
I would say that adding a pair of GOOD frame connectors and a pair of Torque Boxes as would be found in a convertible would be a seriously good investment for this particular car.
Again, just my 2 cents. Not taking anything away from your efforts or accomplishment. Just wanting to make sure your investment stays looking good and is safe.
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Good Looking out.
Your points of concern make sense and the solution is practical.
If it were my car I would likely install both structural supports mentioned for the reasons described.
 
Tony,

I certainly appreciate your advice. You have been a great help to me on a number of the things I have needed for this car. My body man and I discussed installing subframe connectors. However, I am not sure what exactly torque boxes are. And I don't take your comments in any negative way. Most of you guys have been doing this kind of stuff a helluva lot longer than me, and I generally take all advice and use it in the best way possible.

whitepunkonnitro said:
It looks good...but I'm one of the guys who recommended he not go this far with this car. Here's why...and PLEASE, I don't mean to be a downer or piss on anybody's parade. I'll just pass this on to anybody who might be considering this sort of reconstruction.
These cars are spot welded together at the factory. The design of the panel and their support is predicated on that sort of welding. When you cut a car apart like this and weld it back together with anything but spots or TIG, the welded seams are much harder than the metal surrounding them. When changing a quarter, or a floor pan, it's not a big deal. But, the roof structure is an active part of this cars chassis. If you've ever cut the roof off a hardtop and tried to lift the car, you'd see just how much rigidity the roof adds. As this car rides over bumps, and goes through cornering and stopping motions, the soft original metal will want to move slightly as it was intended...the hard seams will not. It's just a short time before those areas become work hardened and begin to crack. In the event of a serious accident, the metal will tear like tissue paper along the seams. There's a lot to this!
I would say that adding a pair of GOOD frame connectors and a pair of Torque Boxes as would be found in a convertible would be a seriously good investment for this particular car.
Again, just my 2 cents. Not taking anything away from your efforts or accomplishment. Just wanting to make sure your investment stays looking good and is safe.
Click to expand...
 
whitepunkonnitro said:
It looks good...but I'm one of the guys who recommended he not go this far with this car. Here's why...and PLEASE, I don't mean to be a downer or piss on anybody's parade. I'll just pass this on to anybody who might be considering this sort of reconstruction.
These cars are spot welded together at the factory. The design of the panel and their support is predicated on that sort of welding. When you cut a car apart like this and weld it back together with anything but spots or TIG, the welded seams are much harder than the metal surrounding them. When changing a quarter, or a floor pan, it's not a big deal. But, the roof structure is an active part of this cars chassis. If you've ever cut the roof off a hardtop and tried to lift the car, you'd see just how much rigidity the roof adds. As this car rides over bumps, and goes through cornering and stopping motions, the soft original metal will want to move slightly as it was intended...the hard seams will not. It's just a short time before those areas become work hardened and begin to crack. In the event of a serious accident, the metal will tear like tissue paper along the seams. There's a lot to this!
I would say that adding a pair of GOOD frame connectors and a pair of Torque Boxes as would be found in a convertible would be a seriously good investment for this particular car.
Again, just my 2 cents. Not taking anything away from your efforts or accomplishment. Just wanting to make sure your investment stays looking good and is safe.
Click to expand...

Definitely a valid point. MIG welds are more brittle than other types of weld, at least in the general sense. That's also not to say that there's nothing you can do to reduce (not eliminate) that situation.

But I think in this particular case the point may be overplayed a bit. All of the roof structure kept it's original spot welds. By taking the replacement all the way out to the cowls, the forces are diffused quite a bit. There's a lot of area, and a lot of weld locations, by going all the way out to the cowls as was done here. If the roof was removed by just lopping off the A and B posts and welding around them, I would be a heck of a lot more concerned about the welds.

That's not to say I wouldn't install frame connectors or torque boxes. I think those are a good idea for ALL of these cars, as they were pretty flexy from the factory. And in this particular case I think it would be good additional protection considering all the work that was done. But I don't think you'd see cracks around all of those welds in short order, or that the car would have a systemic failure in a crash if those precautions weren't taken simply because of the area that those forces are spread across in this particular instance.

I'd still add the frame connectors and torque boxes though. :D
 
I agree with the stated concern, however, keep in mind it will be a lot stronger than a convertible. Given what you've done frame connectors and torque boxes are a minor project. There's lots of frame connector threads on this site. I can post a torque box pic if you like.
 
Great job on what you have done so far. I like persistence.
 
whitepunkonnitro said:
It looks good...but I'm one of the guys who recommended he not go this far with this car. Here's why...and PLEASE, I don't mean to be a downer or piss on anybody's parade. I'll just pass this on to anybody who might be considering this sort of reconstruction.
These cars are spot welded together at the factory. The design of the panel and their support is predicated on that sort of welding. When you cut a car apart like this and weld it back together with anything but spots or TIG, the welded seams are much harder than the metal surrounding them. When changing a quarter, or a floor pan, it's not a big deal. But, the roof structure is an active part of this cars chassis. If you've ever cut the roof off a hardtop and tried to lift the car, you'd see just how much rigidity the roof adds. As this car rides over bumps, and goes through cornering and stopping motions, the soft original metal will want to move slightly as it was intended...the hard seams will not. It's just a short time before those areas become work hardened and begin to crack. In the event of a serious accident, the metal will tear like tissue paper along the seams. There's a lot to this!
I would say that adding a pair of GOOD frame connectors and a pair of Torque Boxes as would be found in a convertible would be a seriously good investment for this particular car.
Again, just my 2 cents. Not taking anything away from your efforts or accomplishment. Just wanting to make sure your investment stays looking good and is safe.
Click to expand...

Here I thought the cars were spot welded together was because it was quick and cheap. I had no idea it was to enhance structural integrity.....go figure???

nice job 1969VADart !
 
HemiDenny said:
Here I thought the cars were spot welded together was because it was quick and cheap. I had no idea it was to enhance structural integrity.....go figure???

nice job 1969VADart !
Click to expand...


No...you misunderstood the point. Spot welding does not increase the structural integrity, but the WAY the panels are stamped and fit together, they are designed to be spot welded. That's why there are pinch weld seams and not just overlaps. The weld seam holds rigid, the metal around it is designed to flex.
Adding Mig seams alongside original spot seams is a double rigid and the closer they are to eachother, the more pronounced the load on the metal in between is. Those are the area I would be concerned about work-hardening in normal use.
From a safety standpoint, I'm not saying that this car is going to hit a bump, crumble and burst into flames. I'm sure it would hold up fine in a fenderbender, BUT, in any sort of severe impact, the metal adjoining the MIG seams ABSOLUTELY WILL rip like it's made of cardboard. I've seen this many times over the years where quarters and whatnot that were Mig'd, tore in an accident.
 
I feel your pain on this. I went through something like this on my 72 Demon.
 

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Wow! Just WOW! That's some crazy stuff there!
 
I'm like 1969VADart, Just what are "torque boxes" and what do they do?? I've seen them listed in the parts books with pictures of them but I fail to understand them and just what they do. Any way to help VADart and me here guys?

Jim
 

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Torque boxes for the A-body. The wedge shaped ones go against the rails behind the front wheel, the box shaped ones go against the rails in front wheel. These are usually found in convertibles and wagons.
 

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whitepunkonnitro said:
No...you misunderstood the point. Spot welding does not increase the structural integrity, but the WAY the panels are stamped and fit together, they are designed to be spot welded. That's why there are pinch weld seams and not just overlaps. The weld seam holds rigid, the metal around it is designed to flex.
Adding Mig seams alongside original spot seams is a double rigid and the closer they are to eachother, the more pronounced the load on the metal in between is. Those are the area I would be concerned about work-hardening in normal use.
From a safety standpoint, I'm not saying that this car is going to hit a bump, crumble and burst into flames. I'm sure it would hold up fine in a fenderbender, BUT, in any sort of severe impact, the metal adjoining the MIG seams ABSOLUTELY WILL rip like it's made of cardboard. I've seen this many times over the years where quarters and whatnot that were Mig'd, tore in an accident.
Click to expand...

I see / saw your point....I'm just say'n (from the general consumer point of view)....I thought they spot welded because it was fast and cheap and (added) I can only surmise, took less skill to perform.

you are way above my pay grade on the welding analysis......A-OK with me.
 
whitepunkonnitro said:
It looks good...but I'm one of the guys who recommended he not go this far with this car. Here's why...and PLEASE, I don't mean to be a downer or piss on anybody's parade. I'll just pass this on to anybody who might be considering this sort of reconstruction.
These cars are spot welded together at the factory. The design of the panel and their support is predicated on that sort of welding. When you cut a car apart like this and weld it back together with anything but spots or TIG, the welded seams are much harder than the metal surrounding them. When changing a quarter, or a floor pan, it's not a big deal. But, the roof structure is an active part of this cars chassis. If you've ever cut the roof off a hardtop and tried to lift the car, you'd see just how much rigidity the roof adds. As this car rides over bumps, and goes through cornering and stopping motions, the soft original metal will want to move slightly as it was intended...the hard seams will not. It's just a short time before those areas become work hardened and begin to crack. In the event of a serious accident, the metal will tear like tissue paper along the seams. There's a lot to this!
I would say that adding a pair of GOOD frame connectors and a pair of Torque Boxes as would be found in a convertible would be a seriously good investment for this particular car.
Again, just my 2 cents. Not taking anything away from your efforts or accomplishment. Just wanting to make sure your investment stays looking good and is safe.
Click to expand...

Well said.
 
That wasn't cancer, that was leprosy! And Im scared to cut a 2X3" section out of my fender.....
 
It seems no matter how many pictures I see of these kind of super ambitious
rust repairs I am always blown away.
I believe I shall call you a pro now ready or not. You earned it in my book.
That is a over the top save.
 
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