Tuesday, 30 September 2014

Back to the pan

So much of my time lately has been absorbed in researching, thinking and planning the next stages of the resto. However, I think it has been necessary for me to take a back step, reassess the priority areas and unblock some issues that were preventing me progressing. Ultimately I concluded that I needed to refocus my attention on the chassis and crack on with maximum vigor! Firstly, I had a brain dump and wrote out a check list (in no particular order) of all the odd jobs that need doing before the chassis would be ready for paint: 



I have now set myself up with a decent supply of Argon/C02 welding gas: 

  

With a new regulator fitted and plumbed into the MIG welder. It works like a dream:

video

The WW floor pan halves that I bought a while back were designed for a LHD car and I needed to consider how I would go about converting them to RHD and make it correct for for a '65 pedal assembly setup. Through my research it became apparent that there should be a small strengthening/reinforcement plate which supports the pedals. Some bugs appear to have this strengthening plate visible on the top side of the floor pan, but there was no trace of this when I dismantled the components from the old pan. Strange I thought... then I recalled cutting through what I thought was an old scabby repair patch last year and realised that it was actually the reinforcement plate (the layers of rusted crud were masking its true identity!). An intensive search on Google images and various VW forums confirmed that the plate sits underneath the pan on the '65 model. Luckily I have been retaining all the old scrap cut from the car to use for welding practice. This was this old chunk that I was looking for: 


I chiseled off all of the rust flakes and it all became obvious:

The plate itself is basic enough, so I will be making a new one out of 5mm flat bar. The long edge is basically seam welded to the point where the edge of the Naps hat and bottom plate meet. The short edge is seam welded to the lip of the chassis tunnel and there are also a series of spot welds that fasten the floor pan to the strengthening bar. The two (threaded) holes in the middle are for the mounting brackets, which sit on top of the pan – which is fortunate as it means that I will just needed to drill 2 holes in the new drivers side floor pan in order to adapt it to RHD.

The only minor problem was that I had not cut this piece of flush when I separated it from the tunnel. This obviously meant that the plate was now slightly shorter than it should be, but I did not know by how much exactly. After a thorough rummage through the scrapped pan offcuts I reconstructed the front edge of the old pan. I then clamped the plate to the old floor pan scrap being sure to line up the bolt holes: 


I then clamped the reconstructed mess to the chassis tunnel in its original position for assessment. This enabled me to ascertain how much of the original reinforcement plate had been trimmed off: 


and here is the view from the underside:


Turned out that the plate was between 8-9mm short:


Armed with this new knowledge I created a reference drawing to act as a pattern (see the red outline) for when I make the replica part. I probably spent far too long producing this in Photoshop, but if it's worth doing then it is worth doing right:

Wednesday, 3 September 2014

Vinegar, rinse, blast, paint, repeat...

After a lot of experimenting I have finally settled on a method for taking rusty components and transforming them back to good-as-new. It all starts a lot of vinegar, citric acid powder and a Bristol City council recycling bin:


I came across this method after reading through an amazing build thread over on Volkszone, so full credit to Andy Sweeney (aka: Last Triumph) for originally sharing this idea.  Basically, once the vinegar and citric powder have been mixed, you simply submerge the dirty components in the acid bath as they are, close up the bin lid and wait. Over the course of a week or so the solution dissolves the grease, dirt and much of the rust. 

A word of warning in case anyone reading is considering doing this; the vinegar bath should be used on components that do not have a structural purpose. This is due to potential embritllement, which could compromise the integrity of such parts. So, no suspension, steering boxes etc!

The results straight out of the bath are impressive... Here is a before shot:


After:


However, when I put a second batch of components in the vinegar solution I unintentionally left them in a bit too long (summer is full of distractions and tangents!). When I pulled them out I was baffled to find that they were covered in a stubborn residue like a coral reef:




I am unsure if this is the result of the sediment from the previous components that were cleaned or simply what happens when you leave metal parts submerged for too long. I guess another possibility is that the citric acid powder and vinegar somehow breaks down or alters over time?

Unexpected coral reef cultivation aside, the parts are then rinsed in water and any loose dirt is cleaned off with petrol and a toothbrush or wirebrush:


The parts then go into the blast cabinet and without that stubborn coating of several decades worth of accumulated crap encasing everything, it only takes a minimal amount of time before they are done. Not only does this process remove the last traces of rust, but also provides a perfect key to the surface ready for paint:


Its then a case of masking (if required), mixing up some Mastic 121 and painting it on using a regular brush: