Dumb Newbie w/Front Quarter Panel Replacing Questions

[vamram]

Hello Body & Paint People!

First time posting on the body/paint forum...well, maybe not the first, but close to it. I posted this in an old thread I have in the '68+ Beetle forum but figure this is probably a better place, hoping to take advantage of your skills and expertise.

The scenario - I need to replace the driver side front quarter panel on my '74 Super. Not the wheel well, strut tower or apron, those are fine. The outer skin though has the contours of a large potato chip, rendered thus in some front end accident eons ago by a PO, and fixed w/puller holes and like an inch of bondo. I removed the bondo and, based on the good advice of more knowledgeable folk (Jimbo, Buggee and others), found a donor panel to replace THIS:

Here's the donor skin, treated w/phosphorous for the surface rust, washed and dried.

I was thinking of cutting out the section holding the brake fluid reservoir shelf from the existing panel, then butt-welding this complete section to that area before cutting anymore out, using 45 degree cuts on the overlap. I based that on what else - a youtube video I saw where the guy was showing how he butt-welded a replacement panel and gas tank door on the bed of an old pickup truck. The result was pretty slick and made sense to me.

Link


Any advice is welcome before I start cutting!!
_________________
Eventually, "we are what we pretend to be.’”
Give peace a chance - Stop Russian-Soviet Aggression!!

'74 Super 9/16 - present, in refurb process.
'73 Super - 6/18 - Present - Daily Driver!
'75 Super Le Grande...waiting it's turn in line behind '74.
Click to view image
Save the Supers!!

[viiking]

I've done a small section of the quarter panel but not as much as yours.

My thinking is that the closer you are to a fold or say the fold-over seam of the A pillar the less likely you will have distortion. That is, distortion seems to happen most in the middle of an unsupported panel and not so much where the bend or seam gives some rigidity.

It's a bit hard to see your panel because of the colouring. Maybe sand it back down to a shiny surface may help other posters

I would cut it as close to the existing A pillar that you can whilst still letting you easily weld and grind. Maybe an inch away. Ditto with the top section near the hood and "underneath" the fender well so the welding is not so visible on the external surface.

I've use the butt weld clamps that leave a small gap between panels with some success. I don't try to have no gap as I think that just "wells" up the weld bead. Grinding to a 45 just thins the metal out at the gap and probably just gives the same result as the butt weld clamps but my opinion is that it just leads to more burn through as the metal thickness varies between the top and bottom of the V.

Whatever you do, do the tack, cool, tack cool. Then once you have done one set of welds, go back and grind down each weld before doing one overlapping tack. If it needs a dolly and tap, do it as you go.Then again do all of them, then grind down the weld again. Do this until the whole panel is welded.

Why? Because if you try and tack onto a blob of a weld, you just pile it up even higher and the penetration is variable. By grinding down the weld to the same thickness as the base metal and tuning your weld settings, you will get a better flatter weld. I use the edge of a thin cutoff wheel to take the welds down flat. Do your final metal finishing when all the weld is complete.

I was inexperienced at welding but have learned by making lots of mistakes over the past few years, but it is common sense with a bit of practice.
_________________
1968 1500 RHD Lotus White Beetle since birth. In the hospital for major surgery
1966 Lancia Flavia Pininfarina Coupe - in the waiting room
Discharged: 1983 Vanagon, 1974 1800 Microbus,1968 Low Light,1968 Type 3

[infiniteLoop]

leave 1-2 inches off from the pillar and go right to the corner or maybe 1/4" off from the curved part. Then place your donor piece over it and see if any unknown issues are present.

[bomberbob]

I replaced the entire quarter from the pinch weld, all the way to the front apron. My quarter did not look as bad as yours, but it was full of pounds of bondo. Previous owner tried to hide accident damage and rust. Along with the quarter, I also replaced both heater channels, the forward bulkhead, both A pillars, and other assorted rusted out spots. I first considered just replacing the section you are doing, but after thinking it over I just cut out the whole thing. My pinch weld looks goofy, the rest of it looks nice.

_________________
1968 Beetle (storage)
1990 Jetta GLI megasquirted, burning E85 (currently in heavy maintenance)
2004 Jetta turbo GLI
Marion, Iowa

[vamram]

Thanks all for the great tips. I am going to take a few whacks at it w/hammer and dolly just for the record, but I'm 99% sure there will be ultimately be cutting and welding. Bomberbob, I can confirm that the damage on my is not nearly as severe as yours must have been. Fortunately the wheel wells, apron, and heater channels are all solid.

Viiking, I understand why you don't like the idea of the video's 45* cuts, but doesn't the fact that he left the edge of the area to weld over in place resolve the issue of thin metal at the spot welds he lays?
_________________
Eventually, "we are what we pretend to be.’”
Give peace a chance - Stop Russian-Soviet Aggression!!

'74 Super 9/16 - present, in refurb process.
'73 Super - 6/18 - Present - Daily Driver!
'75 Super Le Grande...waiting it's turn in line behind '74.
Click to view image
Save the Supers!!

[evanfrucht]

I would NOT use that butt welding technique from the video on the front quarter.

Get yourself a large pile of welding clamps, magnet style, vice grip, your favorite, etc... and you will have less problems. You want to have atleast maybe 20 or so at your disposal.

Start you cut small. Leave a couple inches of material you will eventually remove, just at first, to check fit.

As you check the fit, trim material away SLOWLY. You can always cut more but you can't go back in time. Make sure the gaps don't get screwed up. Check fit about a dozen times before you tack it in and then study the work very carefully, BEFORE you do the final welding.

Inititally put tack about every 4cm. Then when you do the final welding you stitch weld up one of those 4cm sections at a time. On a panel like this I'd probably use what you might call a "CLOCK" technique.

Basically start at positions 12, 6, 9, 3 then go back next to the first one you did and start at 1, 7, 10, 4. Then finally 2, 8, 11, 5. That's the basicall idea. Basically just mark out a crude degree wheel on the quarter panel, and roughly follow that. The point of doing all this is to prevent the panel from warping unevely or uncontrollably at the weld seam.

Wherever you weld it shrinks the metal, keep that in mind. One technique is to actually hit the hot weld bead with a hammer (ON dolly) to stretch it back out... but that is a skillful operation and you can do more harm than good if not careful.
_________________
1967 Bug ( the daily rod )
1964 Fury Wagon ( the pavement shredder )

[viiking]

[viiking]

[Busstom]

[vamram]

Gents - thanks for all of the great lessons/advice. I decided to keep the updates in one place, on the thread I started eons ago when I bought this Super. Updates are in the last couple of pages here in the '68+ forum. https://www.thesamba.com/vw/forum/viewtopic.php?t=...;start=700

I decided to try the old hammer and dolly and did actually have some pretty darn good results. Question I'm faced now is do I cut less since I've been able to straighten out quite a lot of the surface, and if so how much, or just cut out more to have a complete panel that will require less filler.

Víctor

_________________
Eventually, "we are what we pretend to be.’”
Give peace a chance - Stop Russian-Soviet Aggression!!

'74 Super 9/16 - present, in refurb process.
'73 Super - 6/18 - Present - Daily Driver!
'75 Super Le Grande...waiting it's turn in line behind '74.
Click to view image
Save the Supers!!

[viiking]

In my opinion I would remove the damaged section completely. The fear is that you have so many wrinkles that even with dolly work you are going to stretch the metal and have problems with resolving that.

Whilst the welding imparts problems too, I think that having the least amount of body work to do in your case would be the best. If your replacement piece is in good shape, then you only have to deal with filling at the weld seam (if you cannot hammer and dolly the weld depression out. With so many divots in your QP that require bondo, I think it will be a poorer repair.

Now in saying this, I am not a body guy, but have learned a lot from making mistakes on panels like you have.

I'm sure others may chime in.
_________________
1968 1500 RHD Lotus White Beetle since birth. In the hospital for major surgery
1966 Lancia Flavia Pininfarina Coupe - in the waiting room
Discharged: 1983 Vanagon, 1974 1800 Microbus,1968 Low Light,1968 Type 3