body and interior Help and advise on roundie rear tail clip/panel

[Jae]

Hey everyone!

I'm looking for some help and/or advise. I have a 71 roundie I picked up last summer to restore and came across an issue regarding my tail clip. I noticed a few cracks here and there around mostly mounting holes. (Emblem, license plate lights, between tail molding). So I start to pick at them and slowly but surely pieces of bondo starts chipping off and eventually it starts coming out more and more. After some time, it's obvious that my 02 had some damage back there that was repaired. My question is would I be better off trying to repair the sheet metal or replace the tail clip altogether? I've checked around the taillights and under the rear and notice it's seam welded. I've searched and seen some other replace it but not really a "how to"step by step. I'm knowledgable with a weld. Any help and suggestion or advise is appreciated.

Also, the car is in otherwise amazing shape. I checked all the known areas of rust (floor board, shock towers, wheel well, rockers, etc) other than minor rust spots, I was able to repair everything else. I'm kicking myself for not checking the rear clip.

Edited January 11, 2016 by Fredric_P

[Pigpen]

Damn-Looks like the last dude used a 16oz ballpeen to that panel!

Before cutting it out, buy a set of hammers and dollies from eastwood ( about $25 to 35 bucks over the holidays) and their $16 book on dent repair. You will be amazed at how much of a beating that German steel from the 70's will take. Don't forget: NEVER hammer without a dollie backing it up, and you will be fine. I bet in an afternoon, you will have most of that fixed. It will take you two to three times longer to drill out all the spot welds and replace the panel.

Mark

[Simeon]

Panels will need some filler, a skim coat over sound steel, sanded to raise low spots is no crime. Fully strip the panel, verify it is fully sound. Have fun getting the worst of the dents out with your new hammer set. Spray a sealing coat of epoxy primer and then follow with a few repeated skim coats of filler, block sanded so that most ends up on the floor. Follow with a nother coat of epoxy primer so the filler never sees moisture again. This should remove any waves and dips in the panel. Hard work but that's how it goes.

[Jae]

Thanks for replying.

I was doing a little more investigating and I may have found the initial damage area. It appears it's been hit on the lower right side, above the exhaust tip loop where the bumper bracket mounts too. It's actually rusted through on that area only. I was able to remove most of the old bondo too bare metal now.

I'm going to start doing some hammer and dolly work and I'm not so sure what to do on the rusted through area yet.

[TobyB]

You'd be hard pressed to find a roundie that DIDN'T have rear panel damage.

And that repair technique's pretty common- it adds stiffness to a stretched panel

without taking any real time to try to re- shape the panel.

 

you will become the king of the oilcans as you work on this one, I can almost guarantee.

 

Look up 'metal shrinking' on the interwebs- you use heat and the hammer and dolly to shrink

the stretched (ball- peined) divots, and restore some structure to the panel.

You'll never get it exactly perfect- if that matters, put in a new panel.  But I agree, a new panel takes

days to do, and that looks like a couple of easy days to repair.  But recreating the original shapes without

a reference will be tough- there are a lot of little planes stamped into that panel.

 

Strip the ledge below where you've stripped- if that's significantly deformed, I'd say it's almost worth

replacing the whole panel.  Because, as you work the upper portion, the radius into the lower ledge absorbs

and replenishes metal, and it's REALLY hard to tell what the hell is going on if you haven't done it a few times.

And even if you have, getting it perfect can take days.

 

I know this is no help now, but a quick feel from inside the trunk will always tell the tale on this stuff.  Even if it's been

filled on both sides, you can easily feel the thickness of the panel.

 

If the rest of the car's near perfect, and you like having a perfect car, replace it.  If you want to learn... well, this is not

an easy place to start, but let's face it, it's not like you're starting with something that you could HURT much!

 

t

[Jae]

Thanks for the advice all. I think I may bite the bullet on this one and just replace the panel. I've already started with the process. Everything has been removed (gas tank, bumper, lights, trunk latch and locks etc) I also scrapped all the seam sealer from the inside bottom to the seam welds behind the tail opening.

I'm going to start using my stripping wheel to locate the welds on the outside lower valance (if there are any).

Looking under the tail panel I see where the trunk floor and rear panel are welded together so hopefully I can get this off without damaging or bending the trunk floor metal.

Any thing else I should know or suggestion before I start cutting away?!?! Thanks everyone.

Edited January 13, 2016 by Fredric_P

[TobyB]

Get the new panel in hand first.

 

Then:

 

sacrifice the old panel.  cut it almost all the way away, but leave just a strip of it.  THEN work

on the welds.  It's a LOT easier that way, and you don't distort the mating panel.

 

The weld that join the panel to the rear quarters is a butt weld, and it is harder than hell.

Grind it with a sharp new disc(s), and take your time.  Be careful not to distort the quarter panel.

 

Prefit your taillights before you weld a damned thing.  Then your trunk lid, altho that's a lot easier to fake later.

 

Clecos make life a lot easier, as do welding clamps, c- clamps, needle- nose vice grips, and sheet metal screws.

 

Good luck!

 

t

[Jae]

Thanks Toby. I'm sure I'll have a lot of fun with this.

[winstontj]

Thanks for posting this. Made me go back and find/bookmark this:

 

http://www.bmw2002faq.com/topic/175222-must-see-video-reproduction-of-2002-tii-by-bmw-mobile-tradition/

 

Its a very good video. Until I read Toby's post I would have sworn that the rear panel is brazed and then leaded to the quarter panels just like the front nose is to the fenders. At least on the top. If its welded it looks like it is welded on the inside of the trunk (at the flares) not butt welded on the exterior. 

 

Either way, here are a couple photos of my '71 rear joints. Looks to me like my driver's side is OEM and is leaded and the passenger side has been replaced and welded poorly. 

 

As Toby said, if you are going to swap out the metal, sacrifice the old one. Do you have lead in the rear seams of your tail/quarter joints?

 

[TobyB]

Yes,

sorry, at the top it is a flange weld, where the lips were folded back

then "Heli-Arced" together where they folded around into the trunk.

 

 The weld itself is akin to diamond.  But to preserve the original

look, it matters to keep the fold the same, so you have

to grind the sucker down to the height of the lip of the replacement panel.

 

t

[Jae]

That's a great video. That will help me a lot. But to answer your question, It does look like its leaded in the seams. Just by looking at the weld seams, it's never been replaced before.

[TobyB]

If it's original, it should look exactly like the middle pic that Winston posted.

 

If it's leaded farther, that's been repaired.

 

Really common.

t