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Discussion Starter · #1 ·
Hello all first time post here
purchased a 67 "relatively" rust free project this fall and have been at it ever since
car is pretty solid now that rockers and lower quarters have been replaced

Problem now is that a previous owner put a big aftermarket sunroof in and I want to remove it..
Seems like getting another roof and cutting out whats needed and just patching the hole is not the correct method because of panel warpage from welding and the use of too much bondo when finishing.

So correct method would be to cut the roof off and find another..... ugh

My question is does anyone know where the factory made the welds when they attached the roof?
I looks like the front pillar might have been attached right at the body - the rear is unclear just below the drip rail?
there is definitely some lead there so its a likely spot but on the inside i see no trace of a weld

anyone? -- much appreciated
 

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Check out the threads by NOHOME and 68EFIvert. They have done enough body ripping and modifying that if you contact them, they could probably give you a pretty good idea where the join is.

Than said, I would be inclined to take just the section from a donor roof and tack and hammer weld it into place. You are correct that because of the relatively little curvature in the panel, there is great potential for warping; however, a good sheet metal guy will do it with a minimum amount of warping and can heat shrink out a lot of the distortion. There should be very little requirement for body filler. Its not something that I would try because I pretty much fall into the snot ball welder class. This might be something you want to farm out to a body specialist.
 

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Discussion Starter · #4 ·
Check out the threads by NOHOME and 68EFIvert. They have done enough body ripping and modifying that if you contact them, they could probably give you a pretty good idea where the join is.

Than said, I would be inclined to take just the section from a donor roof and tack and hammer weld it into place. You are correct that because of the relatively little curvature in the panel, there is great potential for warping; however, a good sheet metal guy will do it with a minimum amount of warping and can heat shrink out a lot of the distortion. There should be very little requirement for body filler. Its not something that I would try because I pretty much fall into the snot ball welder class. This might be something you want to farm out to a body specialist.
tnx guys

The closer I look I am thinking the factory may have first welded the underside roof frame to the body - then put the skin over it which seems more logical

Well that s my inclination as well to do a section repair - I can do a passable welding job on the rockers but i would hate to mess up the beautiful roof line of the car
I have located a roof and I will take all of it down to the body - so I have options available

I guess my other option is to try to renew the sunroof - but between all the metal work so far and the cost of the future paint job - might be a bad move if I sell the car someday
 

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You are not going to like the answer. The roof panel is not spot-welded. The weld is one continuous spot weld made with a pair of rollers. It would be quite fun to replicate.

I believe this video has a section where the roof panel is going on.

https://www.youtube.com/watch?v=BGRDLnHnJgE

I would hammer weld the filler piece in if doing what you propose. If you want more insight into what hammer welding is, just ask.
 

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Check out the threads by NOHOME and 68EFIvert. They have done enough body ripping and modifying that if you contact them, they could probably give you a pretty good idea where the join is.


, a good sheet metal guy will do it with a minimum amount of warping and can heat shrink out a lot of the distortion. There should be very little requirement for body filler. Its not something that I would try because I pretty much fall into the snot ball welder class. This might be something you want to farm out to a body specialist.

Actually, a good tin man will stretch the distortion out!

The reason that panels distort has nothing to do with the heat put in to the panel. And for the most part the old saw of "weld slow and let it cool down" does nothing to help. Even worse is the "cool the weld with an airgun"

The reason that you have distortion in a welded panel is because the weld bead that you lay down SHRINKS as it cools. As the liquid metal solidifies, it shrinks, it pulls on the sheetmetal on either side and draws it in towards the center of the bead. This pulls the crown out of either side of the weld bead.

The solution to this problem is to "stretch" or spread the weld bead by hammering it against a dolly held behind the bead. You need to do a series of very small weld tacks, grind the majority of the weld bead down, measure the distortion, hammer to release the strain, then repeat until you are done. A good tinsmith can do about 12" of weld/ hour using this process.
 

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Discussion Starter · #8 ·
tnx NOHOME -Ive been reading up on hammer welding - seems like the way to go if I can find a competent craftsman
and fgkouki tnx - Im in NY and have found a roof in Mass - a bit more convenient than South Carolina
 

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Actually, a good tin man will stretch the distortion out!

The reason that panels distort has nothing to do with the heat put in to the panel. And for the most part the old saw of "weld slow and let it cool down" does nothing to help. Even worse is the "cool the weld with an airgun"

The reason that you have distortion in a welded panel is because the weld bead that you lay down SHRINKS as it cools. As the liquid metal solidifies, it shrinks, it pulls on the sheetmetal on either side and draws it in towards the center of the bead. This pulls the crown out of either side of the weld bead.

The solution to this problem is to "stretch" or spread the weld bead by hammering it against a dolly held behind the bead. You need to do a series of very small weld tacks, grind the majority of the weld bead down, measure the distortion, hammer to release the strain, then repeat until you are done. A good tinsmith can do about 12" of weld/ hour using this process.
I can't argue with that, although, I did manage to put a nifty bulge in a 1/4 panel just with heat, didn't ever get to the point of laying down a bead. I now leave all that stuff to competent sheetmetal dudes.

I was watching a sheetmetal worker deal with some small panel distortions by heating a section of the panel and then tapping. He referred to it as heat shrinking; however, the actual effect on the metal was more like stretching. It may have been just his semantics!

The hammer welding I was referring to was the process by where you join two pieces of body metal together with a butt weld process. No lap at the weld joint. Heat the parent pieces of metal up and then hammer the joint with a hammer backed by a dolly. Done perfectly there is no filler rod involved. Are you talking the same process?
 

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I can't argue with that, although, I did manage to put a nifty bulge in a 1/4 panel just with heat, didn't ever get to the point of laying down a bead. I now leave all that stuff to competent sheetmetal dudes.

I was watching a sheetmetal worker deal with some small panel distortions by heating a section of the panel and then tapping. He referred to it as heat shrinking; however, the actual effect on the metal was more like stretching. It may have been just his semantics!

The hammer welding I was referring to was the process by where you join two pieces of body metal together with a butt weld process. No lap at the weld joint. Heat the parent pieces of metal up and then hammer the joint with a hammer backed by a dolly. Done perfectly there is no filler rod involved. Are you talking the same process?
Same deal. You can't hammer weld a lap joint.

You don't have to heat anything up to hammer weld. The idea is that you need to "stretch" the zone where you welded because the molten weld bead contracts as it cools, and gatherers in the metal on both sides of the seam.

The metal is stretched by putting a dolly in behind the seam and hammering the top of the seam against the dolly. This squashes the metal out and relaxes the panels back to the proper shape.

If doing this with a MIG weld, you grind down most of the seam before you start beating on it.

Takes a lot of time to do well no matter how skilled you are.
 

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You don't have to heat anything up to hammer weld. The idea is that you need to "stretch" the zone where you welded because the molten weld bead contracts as it cools, and gatherers in the metal on both sides of the seam.
The process that I saw was different. A short section of the butt joint was heated to the point of incandescence with an oxy acetylene torch and then joined by the process of being pounded between the hammer and the dolly. Struck me as an awkward process since the differential heating of the joint resulted in some panel movement. I guess the trick was heat very small sections and then work them. The metalworker may have had to do some cold stretching as you describe, I didn't stick around for the complete process. The end result was excellent. As you note, a time consuming process.

I have often wondered whether the heating and beating as it cooled resulted in any work hardening and embrittlement of the panel in the join area. I guess if some day I hit a really bad bump and the panel section fractures and falls off, I will know why.
 
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