Oval window conversion for your Baja, sir?

You may have noticed the oval window clip hanging up in the garage?
I've always fancied an oval-windowed baja, but even I would never butcher a real oval.

I decided I would only attempt the conversion if I could do it right; this involved finding a method of properly grafting the panel in place. Properly means securely, rigidly, inflexibly - as if it grew there!

Butt-welding was out of the question on a panel of this size and shape, maintaining an even 1mm gap all around the panel? A panel with this much edge?
After much deliberation and head-scratching there was only one way...... 
Step-flanging or joggling an overlapping joint was the only way to go for this gig, full strength and some tweaking potential.
Joggling using a normal squeeze joggler, 15mm at a time, would just ruin the edge of the panel and lose all reference to the roof curvature.

Patience, patience

I found a Rola-Step tool.
This little baby uses a pair of driven rollers to form a continuous stepped edge - and has a very small contact area, so no loss of panel curvature.
Once this piece of the puzzle was in place there was no excuse, shit or bust!


Time to make a mess of the recently painted rear window area......

First I drilled out the spot-welds fastening the rear firewall to the window section, there were an absolute shitload of them! Not much metal left.....like swiss cheese.
The joint still held firm despite my efforts so out came Mr.Bosch and off it came, I'm holding the panel back in place to illustrate where the panel joint is.

Next I removed the spot-welds and small tack holding the window surround on the inside.....paint looks good eh?

A bit if chemical assistance was used on the outside so I had a nice clean area to mark up and cut. Since this is a 70's car the rear window is the largest VW made and as such there is very little room for error when choosing where to cut.
The red line indicates where to cut, avoiding the rolled edge of the window aperture and keeping the swage line intact. I just followed the same idea around the corner and across the top.

I realised that Mr.Bosch can't cut around a corner as well as a jigsaw so I went inside to remove the corner sections and allow the jigsaw blade clear passage. All the straight sections were ably despatched by Mr.Bosch and the corners with the jigsaw.

It's out! - both inner and outer window skins.

Oh dear, looks a little forlorn doesn't it?
The only option now is forward....or a convertible

Cleaned out the nasty foam VW put in there to aid corrosion

The removed section compared to the oval

The inner skin of the oval has a return that fouled the inside of the roof so off it came. It wouldn't attach anywhere anyway.

Small sections needed removing to allow the double-skinned panel to slide under the roof skin
They were shot anyway so no real loss......will replace with better metal later.

Oval window section mocked up and clamped, marked position of roof skin on panel and a few reference marks for final positioning

Now to get the rola-step on the job

What a nice job it does

Corners? Easy!

Tacked in and looking sexy, all reference marks aligned

View from inside

Fully welded, entire perimeter of the panel.......

Took bloody ages. One tack at a time, alternating left to right, resting to allow cooling and minimise panel distortion.
Breathe again, loosen sphincter!

Some filler to make up any imperfections, now needs finish sanding and painting

Once finished it will fool casual observers, anyone who really knows bugs will see the tell-tale clues (like the rest of the glass being slightly too big) and know it's a wind-up.
I'm happy though........now to find a full-length rag roof for the complete sacrilege effect