Monday, 9 July 2018

I surrender! The firewall has beaten me

I keep trying and failing to repair the front firewall panel and have reluctantly concluded that it is impossible! 0.7mm sheet steel is just too thin for me to weld without distortion creeping in, even with the MIG on the lowest setting and cautiously tacking one spot at a time. Ggggrrr! Anyway, the spirit of this blog is to always give an honest insight at not just the successes, but also the failures because it offers rich learning for future readers who may be thinking of doing the same. So I invite you to learn from my mistakes...

You may recall a that in a post a while back I was basically using the top section of my original panel and the lower section of a later Mexi panel. The trouble with this section is that VW used a particularly thin gauge of steel and as it is a flat panel it tends to warp and twist as soon as heat it applied. Just trying to get the two sections flush prior to welding proved to be a futile task and my first ill-fated attempt to stitch the sections together became a horrendous mess after only several tacks! So I took some time out and revised the approach. For this attempt I clamped the two sections in a kind of make shift jig that was simply a few lengths of angle iron clamped together with my work pieces sandwiched in the middle:

Now, the problem on that first failed attempt (not shown) was that the two sections buckled and were progressively forming a valley along the width. No matter how careful I was about heat build-up the panel did not want to stay flat and was getting worse with each welded tack. The angle iron in theory would mitigate this issue and hopefully keep things relatively level. As I mentioned, the edges to be welded were not flush all the way along, so I began joining them together in the middle were things lined up reasonably well. 

The temporary jig did work to an extent, but I still got a lot of buckling and distortion issues. Rather than giving up this time I decided to go with it and did my best to work out the kinks with the hammer and dolly as I went along:

It really was like welding two wavy edges together and I would occasionally unclamp the panel and carefully coax things flat and work the worst of the bumps out of the panel before reclamping and continuing on with the welder. I knew this section would never be completely perfect under close scrutiny, but I consoled myself with the fact that it is not an easily visible area of the car and if needs be I could smooth things over with a skim of filler if it came to it. It doesn’t translate too well into a 2D photo, but no matter how carefully I proceeded the panel would end up warped and stretched. 

The prominent discoloured areas are where I attempted to heat shrink the stretching, but as soon as a problem was solved in one localised area, an equally problematic area would spring up elsewhere. It was like that old fair ground game ‘whack-a-mole’. In a desperate attempt to correct this I tried cutting out a few of the offending areas and let in fresh flat steel:

As you can tell, it came out pretty well apart from that section at the top which was stretched. So, out came the butane torch for more heat, quench and shrink action. From this point on the panel just became more unsightly as I feverishly chased the problems around the panel like a maddened fool.

Well, I'm now officially done with this sh*t as I am simply losing too much time and heart trying to make it straight, when the reality is that it will never turn out well. Not now.

My distant 'plan B' option was to purchase a Klassic Fab panel and be done with it. However, they only produce them for LHD split or oval Beetles, so adaptions would be required in order to make it work. They are pretty damn expensive for what they are, but fortunately the UK distributor recently run their first (to my knowledge) 15% off funky green sale. I didn't hesitate and pulled the trigger:

Much better. The pressings are pretty close to my '65 firewall, so I am happy to roll with it. Time to roll my sleeves up and convert it over to RHD...

Before I sign off, I thought I would share a photo of my growing collection of Klassic Fab panels. Sobering to think that this represents almost a grands worth of steel, although I think it is best if I just don't think about that fact:


  1. Thanks for the update! I am sure Gretchen is grateful as well!

    1. She is certainly being pampered with the very best parts that I can get my hands on :-)

  2. Have you considered putting a thicker flat piece of copper behind the weld to absorb the heat?

    1. Thanks for the suggestion, Lukas. I did actually try backing with copper, but it made little difference on this occasion. On reflection, I think a more deluxe model of MIG welder is required for this operation - one where you can turn the amps right down. Mine is a fairly cheap (yet very capable) model, but has its limitations.