Friday 17 August 2018

Uniting the front bulkhead panels

So, now that the large firewall panel has been sorted I can now join the smaller inner section of the bulkhead to it to form the finished article. The trail fit looked pretty decent, but the inner section needed a few tweaks to make it perfect. Firstly, the flange on the left side had an awkward step cut into it. No idea why, it was just how the Mexi panel came.To be honest, I probably could have just left it alone, but I that is just not my style. So I cut some steel sheet to fit the profile and clamped it up ready for welding. Note that I left it deliberately oversized to make it easier to weld without blowing through on the edges:

All welded:

Ground flush, shaped up and finished:

In preparation for plug welding I added 6-7mm holes around the edges of the panel, in exactly the same locations that the factory spot welds were. Clamped up and ready for plug welding:

The two sections are now permanently joined:

Good penetration on the reverse:

Dressed the welds and generally cleaned up the panel. Another section of this grand jigsaw puzzle sorted: 


  1. Looking good, sir! That really is some top quality craftsmanship.

    1. Thanks mate, I'm doing my best to keep the quality high and not rush things. Glad to be done with this section though as it has given me so much grief!

  2. It's turned out fantastically!

    1. Thanks Mister Itchy, I appreciate that! Yeah, I got there in the end with it :-)

  3. Hello,

    Man, your skills are just amazing.
    Can you detail what is the process you undertake to get the welding spots ground down to perection? What are the tools you use for this?

    Thank you very much for sharing your restoration process. i am learning a lot from it.


    1. Hi Sorin! Thanks for complimenting my skills, always gives me a little boost to hear that and to know that people value the blog.

      When I next have some plug welds to tackle I will be sure to do a detailed post for you complete with photos showing each step. For now I will try to write a little overview;

      The tools I use to grind down the plugs vary according to the location to be dressed and how difficult access is. For example, I will use my Dremmel tool with a mini grinding wheel for tight spots and for open areas sometimes I go for my variable speed belt sander. However, a majority of the time I have noticed that I intuitively reach for a standard angle grinder with a flap disc attached. This is probably because it is the tool I have had most experience with and know well. Although it works for me I have heard others say that the avoid it for this kind of task because it is too aggressive.

      Anyway, once I have taken off a bulk of the plug weld I adopt a kind of dabbing motion with the grinder angled over at about 45 degrees. This enables me to have precise control over the area being ground and improves visibility. I then trade the flap disc for a 120 grit sanding pad mounted in the angle grinder and do a couple of light passes over the area to level everything off. For final finishing and to smooth everything out I use a dual action sander with a 60 grit disc. The DA sander is the special sauce in my opinion and really makes a big difference.

      If I am ever in doubt I put the power tools down and reassess the situation. Sometimes the hammer and dolly needs to come out to level things back up before final dressing. The one thing that needs to be avoided at all costs is over-grinding and unnecessarily thinning the sheet metal. To that end I would say that the most important factor in the whole process is maintaining patience and developing a soft touch. If you ever feel stressed or rushed then it is better to put the grinder away and work on something else that requires less focus and control. To maintain quality control I will often grind a batch of welds and then do something else before coming back to do another batch. This prevents my eyes getting tired and my mind getting bored.

      I hope this helps - if I haven't covered something you were hoping to learn just let me know and I'll do my best to clarify :-)

  4. Thank you very much. it was very detailed and I've made an opinion on how you tackle these spot welds. It will really help me in the future, as I am also starting work on my 72 Sparkafer Beetle.

    The best to you, and I hope to see Gretchen soon on the streets.

    1. You're welcome. Good to know that I am able to help and to share some of my acquired knowledge. As always, the best way to learn is through hands-on experience. Grab some scrap and practice until you feel competent enough to tackle the actual car.

      Best of luck with your '72 - it is really rewarding to bring these old machines back to life!