Tail Panel removal - need procedure

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Mar 15, 2024
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Location
Austin
My Car
72 Mach 1 H code

72 Sportsroof 351W
I'm looking for the procedure or tips on how to cleanly remove the original Tail panel, without damaging the quarter. etc.

The spot welds seem to disappear on the upper left side, and I'm not sure if some of it was lead-ed in from the factory.

I have a plasma cutter if that's of any use to heat up the spot welds.

Screenshot 2024-10-06 at 7.26.20 AM.png
 
There is no lead in that panel. You need to drill out the spot welds. You can buy a spot weld cutter or use and over sized drill to remove them.
 
You need a spot weld drill. It's like a mini hole saw with a spring loaded pointed tip. Center punch (spring loaded type) the center of the weld to guide the drill point. Only go through as far as the tail panel metal. It will leave a little 'tit" that can be ground off.
I've not actually done this on a panel, but done similar in my past work. If I remember, my body guy drilled appropriate holes in the tail panel so as to weld through, so they look like spot welds.
 
There is no lead in that panel. You need to drill out the spot welds. You can buy a spot weld cutter or use and over sized drill to remove them.

You need a spot weld drill. It's like a mini hole saw with a spring loaded pointed tip. Center punch (spring loaded type) the center of the weld to guide the drill point. Only go through as far as the tail panel metal. It will leave a little 'tit" that can be ground off.
I've not actually done this on a panel, but done similar in my past work. If I remember, my body guy drilled appropriate holes in the tail panel so as to weld through, so they look like spot welds.
Screenshot 2024-10-06 at 8.03.20 AM.png this is what I ordered, I think it's spring loaded but not sure
 
IMG_0111.jpegIMG_0115.jpegIMG_0117.jpegIMG_0116.jpegIMG_0183.jpegIMG_0182.jpegIMG_0184.jpegIMG_0366.jpegIMG_0375.jpegYou will need more than 1. I buy them by packs of 5. If the edge catches it will break off a tooth. After a few teeth break you need to flip the tip and use other side. I keep a handful in my welding cart at all times.
The spot welds can be hard to locate sometimes but with patience you will find them. It’s a pretty straightforward job. Just don’t forget to remove the trunk latch bracket too. Take a few measurements so you put it back in same place and trunk lid closes properly. There’s also a stiffening bracket by each tailight. When you go you reassemble the tailight panel, I would recommend attaching it with self tapping screws before welding. Then install the rear quarter extensions, rear valance, and rear bumper. Make sure everything lines up nicely before welding. If you need to make adjustments it’s easy with self tapping screws. Once you’re happy with the fit, tear it all back off and start welding. Any more questions let me know.
 
When did mine I used a 3/8” / 10mm belt sander with a 36 grit belt. Nice thing about that method is you don’t end up with holes in your good metal from the pilot of the spot weld drill. You just grind away at the spot weld on the tail panel side of whatever it is sandwiched with. As you are throwing away the old tail panel it does not matter that you are making little square holes in it with the belt sander. For videos of this technique look on YouTube. About 2 minutes in on this vid. Make sure that on the quarter panels you remove the spot welds from the inside of the trunk. Don’t grind away at your quarter panels.

Also,
The repop tail panels are very likely to have two problems.

1) The tail light mounting bracket location is sketchy at best. Test fit tail lights before you install the panel. You will likely need to move at least one of the brackets.

2) When the holes for the tail lights are stamped it does not seem like the sheetmetal around the tail light hole is trimmed to an even measurement. In some places it may be 5mm, others 15. Again, check fitment of tail lights. Mark and trim metal to make the lip even. Otherwise you will have issues making your tail lights fit correctly and be weathertight.
 
When did mine I used a 3/8” / 10mm belt sander with a 36 grit belt. Nice thing about that method is you don’t end up with holes in your good metal from the pilot of the spot weld drill. You just grind away at the spot weld on the tail panel side of whatever it is sandwiched with. As you are throwing away the old tail panel it does not matter that you are making little square holes in it with the belt sander. For videos of this technique look on YouTube. About 2 minutes in on this vid. Make sure that on the quarter panels you remove the spot welds from the inside of the trunk. Don’t grind away at your quarter panels.

Also,
The repop tail panels are very likely to have two problems.

1) The tail light mounting bracket location is sketchy at best. Test fit tail lights before you install the panel. You will likely need to move at least one of the brackets.

2) When the holes for the tail lights are stamped it does not seem like the sheetmetal around the tail light hole is trimmed to an even measurement. In some places it may be 5mm, others 15. Again, check fitment of tail lights. Mark and trim metal to make the lip even. Otherwise you will have issues making your tail lights fit correctly and be weathertight.

Oh the joys of reproduction (Chinese?) crap, made by people who just don't give a sh*t.
I'm so glad I didn't have to deal with all that other than a taillight panel that actually did fit. I must have got lucky.
 
I also saw a video where you lightly tap a plasma cutter on the spot weld and it melts it away quick.
I tried that and couldn't get consistent results. Then again, I haven't used my plasma torch, extensively.

My go to's are drill bit if I don't care what's underneath. belt sander to save the underlying panel, spot weld cutter, when I want to save what's under and can clean up (remove the spot weld plug left behind) afterwards. The belt sander does this as an all in 1 type of thing. I get a pry tool between the panels as it gets close, it will pop free. You'll see the metal start changing colors right before it pops.
 
When did mine I used a 3/8” / 10mm belt sander with a 36 grit belt. Nice thing about that method is you don’t end up with holes in your good metal from the pilot of the spot weld drill. You just grind away at the spot weld on the tail panel side of whatever it is sandwiched with. As you are throwing away the old tail panel it does not matter that you are making little square holes in it with the belt sander. For videos of this technique look on YouTube. About 2 minutes in on this vid. Make sure that on the quarter panels you remove the spot welds from the inside of the trunk. Don’t grind away at your quarter panels.

Also,
The repop tail panels are very likely to have two problems.

1) The tail light mounting bracket location is sketchy at best. Test fit tail lights before you install the panel. You will likely need to move at least one of the brackets.

2) When the holes for the tail lights are stamped it does not seem like the sheetmetal around the tail light hole is trimmed to an even measurement. In some places it may be 5mm, others 15. Again, check fitment of tail lights. Mark and trim metal to make the lip even. Otherwise you will have issues making your tail lights fit correctly and be weathertight.

I like this idea, but I think i'm having trouble seeing the spot welds on the tail panel side, and Also I would be needing to remove the brackets on the tail panel first to do this method, but looks really effective and easy.
 
View attachment 93788View attachment 93789View attachment 93790View attachment 93791View attachment 93792View attachment 93793View attachment 93794View attachment 93795View attachment 93796You will need more than 1. I buy them by packs of 5. If the edge catches it will break off a tooth. After a few teeth break you need to flip the tip and use other side. I keep a handful in my welding cart at all times.
The spot welds can be hard to locate sometimes but with patience you will find them. It’s a pretty straightforward job. Just don’t forget to remove the trunk latch bracket too. Take a few measurements so you put it back in same place and trunk lid closes properly. There’s also a stiffening bracket by each tailight. When you go you reassemble the tailight panel, I would recommend attaching it with self tapping screws before welding. Then install the rear quarter extensions, rear valance, and rear bumper. Make sure everything lines up nicely before welding. If you need to make adjustments it’s easy with self tapping screws. Once you’re happy with the fit, tear it all back off and start welding. Any more questions let me know.
Amazon just delivered my spot cutter set. I'll try this and post results.
 
Locating the welds can be a challenge. I used a junk putty knife to force the panels apart slightly, which will distort the metal at the spot welds.

Which cutter you use depends on the location you're working on. The left and right sides, you can use a spot weld cutter, a drill, or any method that preserves the outer sheetmetal. Along the trunk floor, you want to make sure you use something that'll leave the trunk floor/rear crossmember intact and not put holes in it. The spring loaded spot weld cutter will leave a disc of metal that needs to be removed, the other cutter you ordered will remove the metal as it cuts, but be sure to not go into the underlying panels too much.

Another great way to do this is to use an air file with a 1/2" belt. Makes short work of the spot welds. They're heavily used in professional auto body shops, and they're great for dressing down your rosette welds when you're done.

https://www.amazon.com/gp/product/B00L50MKJS

If you have a later D3ZZ NOS panel, it likely has the holes for the '73-only bumper filler panel, which need to be filled for a 71/72 car.

Lastly, and I can't stress this enough, fit, fit and refit *everything* before you commit to welding for keeps. Taillight panel, rear valance, taillights, trunk lid and end caps. Fit it all together to ensure you won't discover an issue after it's welded solid.
 
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