Tuesday, 6 February 2018

Windscreen corner and demister transplant

Since I first got the car there was always a distracting scab of bubbling paint creeping out from underneath the windscreen rubber. Inevitably, that bubbling later became exposed rust as the paint flaked away and finally an ever expanding hole! Annoyingly it was always directly in my eye-line when driving the car and was a stark visual reminder that my pride and joy was slowly rotting away before me. Repairing this offending section would be a symbolic victory against the rust fairies and their psychological taunts of the past!

The divers side corner looked bad from the top side: 


...and was not much prettier underneath:


It would require more than just the mating flanges replacing. My conclusion was that the entire demister section also needed replacing due to the amount of terminal corrosion that had taken hold. I debating with myself endlessly about the best cut lines before finally marking up the area up with masking tape and setting about the task. I have not seen this particular operation done before in other restorations, so it was a 'character building' step into the unknown for me and a real test of my developing skills:



I used the small Dremmel cutting discs to carefully and accurately cut of the section. An angle grinder would have been too aggressive and I felt it could have easily led to errors. So slowly I proceeded. Thankfully my educated guesswork paid off and I was able to lift out the rotten section, complete with integrated demister pipe, in one piece:


On the donor scuttle panel I rough cut the relevant section out so that I could prep it and later trim it down to an accurate fit:


After a session in the shot blast cabinet I had fresh unblemished steel. I was heartened to see just what great condition this section is in:



The only repair I needed to make was a angle grinder gash on the inlet pipe. I guess that the seller who originally chopped out the scuttle from the donor vehicle must have been cutting with haste and this part was a minor casualty. Nothing too serious though:


I filed the protrusions around the cut nice and flat. I then cleaned up a thin piece of copper and added a curve roughly the same as the contour of the pipe. I then inserted the copper backer and clamped it in place with mole grips:


I could then weld up the gap:


After dressing the weld and a quick blow-over in the shot blast cabinet it was looking like new again:


I spent some time carefully trimming up the repair section and repeatedly trial fitted. However, I was starting to feel a little frustrated at this point as I couldn't get the damn thing to line up right on both sides - so I have decided to split the section by drilling out the spot welds:


This allowed me to get a far better alignment on both sides of the dash rather than compromising. Before welding anything permanently into place I took the opportunity to shot blast the soon-to-be inaccessible areas, such as inside the window frame and the top of the door mounting reinforcement panel. Cleaning all this was actually a real pig of a job as it was tough to get the bulky shot blast gun into some of the areas with tricky angles. It was slow going and all I could do was my best, but it is certainly better than just leaving it:



I then added few coats of zinc primer to hopefully prevent any rust re-emerging:  


Starting with the inside section I got the best alignment I could paying particular attention to the contours of the dash.



I really took my time with the welding and started at the outlet end which I determined to be the end that was most critical to get right;


As I moved along the tapering flange section I was able to manipulate the steel slightly and adjust the fit. The occasional vertical slit was added as required to allow the shape to be altered more easily:


All welded and smoothed out and holes filled:


On to the front panel section and I once again started welding at the outlet / corner area before moving towards the centre to complete the weld:



Once the front was welded and smoothed I was just a case of closing the gap between the two sections and plug welding them together. I'm satisfied with the end result as there is virtually no indication of any work having been done;




Couldn't resist a before and after comparison;




Sunday, 31 December 2017

The 'double smile' bulkhead panel

I could put it off no longer - I had to tackle the larger 'double smile' bulkhead panel. The reason that I was fearing this job is simply that the steel is a mere 0.7mm thick, which I knew would be a sod to weld without blowing holes or causing distortion. Additionally I would have to be more cautious than ever when linishing back my welds to avoid overgrinding such thin material.


In a nutshell, the plan was to cut the bottom rotten third off of my original panel and graft on a donor section from the Mexi panel. Sounds pretty straight forward but there were several issues that I identified from the outset. Firstly, the original panel had been patched up in the past with thicker steel plated over the top (you may recall that I removed those unsightly patches back in a previous post). Unfortunately that repairer from yesteryear was rather aggressive with his welding and used a high heat and laid down a continuous bead. The heat build-up must have been immense because the panel had completely warped and distorted. Secondly, the Mexi panel would take some modification for it to look correct on a '65 car. A couple of pressed dimples would need to be deleted and one of the 'smiles' would need to be shortened and reworked to symmetrically match the one on the opposite side. The amount of the Mexi panel I could use was limited by the large protruding rectangular areas. The bottom edge of these impressions became my default cut line, but as one of the 'smiles' extended above this point I decided to tackle it before proceeding any further. I cut out a rectangular section around the end point use a Rotary Tool (i.e - a Dremmel) to keep things as precise as possible and to keep the resulting gap small and consistent. This would help when it came time to weld into position:


  I trimmed off the unneeded length and repositioned the tip so that it lined up perfectly with the other side:

  Carefully welded in:




After making careful measurements of the panel dimensions, I made the horizontal cut along the width of the panel. Note the small piece of angle iron that I clamped in place to add some rigidity in that narrow area. This then was my donor section:

 
I linished the reworked smile:

 
I then deleted the dimples which were positioned too low using heat and a lot of gentle hammer taps to eventually bring it flat:




I then made a corresponding horizontal cut on the original panel:   


  it had a wavy cross section that came from the panel distortion I mention earlier and I spent a great deal of time attempting to put right by shrinking the metal in places. Unfortunately my patience ran out as I just couldn't get it back to anywhere near flat. I did attempt to tack the sections together with the thought that I would possibly work the metal flat as I went along. However, the opposite proved to be true and the panel buckled and twisted up worse than ever, so I cut through the tacks and went for a reset:


Before launching into a hasty second attempt I decided to walk away from this task for a while and do some research on more advanced bodywork methods. Hopefully the start of the new year will yield some better results.

Thanks for reading and I wish you all a happy 2018 :-)

Monday, 6 November 2017

Bulkhead repairs with Mexi steel

Made another thrifty eBay purchase, which came up for sale right when I needed it (what timing!). It's a genuine VW front firewall / bulkhead / cross panel;



Despite being for a '68 and later car I figured I could use generic sections of it to repair my original. Before cutting it up I couldn't resist a quick layout of my Mexi steel collection:


I must confess that I do get a mild thrill when I acquire these Mexi panels. Although they are not as crisp as original German stamped parts, they are still vastly superior to the usual repro options. Talking about repro alternatives, I did actually purchase a Klokkershite panel a while back as I thought I could rework it with some effort into something half decent. My enthusiasm was quashed when I received the panel and I promptly sent it back for a refund!  It was riddled with defects with the spot welds literally coming away at one of the seams. The two sections of the panel were clearly misaligned. Additionally, it was apparent that it had been returned before by someone else as there were pencil marks on it as well as a lot of scuff marks & scratches to the transit paint. I was glad to see the back of it;



Back to the Mexi panel and I carefully drilled out a bunch of spot welds and separated the inner section from the main panel. They were pretty beefy spot welds and I had to drill out to 6mm to get them loose:


Note the small patches of rust already getting a foothold in between the seams - it goes to show that just because the panel is NOS doesn't mean it is corrosion free! I figured I would start with the inner footwell section first as it is thicker steel than the main panel (which is a mere 0.7mm) and therefore easier to weld. I think subconsciously I was after an quick win to boost my confidence before embarking upon something I knew would be tricky. Anyway, I blasted my original so I could make an assessment of its true condition:



Believe me, it was even worse than it looks in those pics. Quite a lot of pin holes and thinned areas of steel along the bottom flange where water had got inside and worked its corrosive magic. I marked up some cut lines and trimmed off the bad sections:



It was then a case of marking up the corresponding sections of the Mexi panel and chopping those out accordingly. I cut them a little bit oversize so that I could finely trim and file to the perfect fit:


Once trimmed up I blasted the donor sections. Here is a comparison between the old and the new. This illustrates just how much of my original had rotted away on the bottom corners:


After a lot of trail fitting, more trimming and rechecking I had the repair sections prepped and ready to weld:



welded, linished and finished (note that I also welded up those unneeded holes):





I did not smooth the welds on the rear side as this wont be visible and will add a little extra strength to the repaired areas. So, that's it for the front panel and I am fairly pleased with how it turned out. 

Still debating the best approach for the main panel, but have a few ideas that are percolating in the back of my mind and work will commence shortly...