Bonnet Progress

 Good progress made - the Clico temporary fasteners were a Godsend.

I managed to weld up the splits where the headlamp part of the bonnet meets the top without any issues. I then ground it smooth with Rolec abraders on an air tool, applied filler and primed it, ensuring I used weld-through primer on flanges where welding needs to take place around the headlight cowls.

Unfortunately, during the process, the bonnet slipped and it received a small ding on the nearside as it fell against some machinery. Fortunately I could hammer it out and skim with filler - any blemish on the underside will be hidden by the mudguards, once fitted.

The manner in which I previously dealt with the dents in the power bulge has given me me cause for concern. As I said in a previous post, I hammered them such that they became slightly concave indents and then skimmed these with filler; however, it's pretty obvious on the underside of the bonnet that there were dents. 

A better approach would have been to try to hammer the dents flat, instead of concave, but my panel beating skills are rudimentary, to say the least. What I really needed was some kind of former against which to beat the dents flat (or at least make them imperceptible), but I had nothing large enough and solid enough on which to place the bonnet and beat it upon. 

On most cars it wouldn't be an issue, but the GT6 bonnet opens in the same manner as the E-Type, from back to front, meaning the underside is a very visible feature when it's open.

Next the front crossmember and headlight cowls were put into place with Clico fasteners. They are brilliant.

Then I offered up the offside the lower wing, which had the flanges stripped of paint and weld-though primer applied, first using clamps and replacing them with Clico fasteners once I was happy with the positioning, which was a bit of a nightmare - push in one bit in and another bulges out, forming a very visible lip. Assistance and some muscle from No.1 Son was invaluable.

I then tackled the nearside lower wing panel, where I had to perform a slight bit of grinding on the headlamp cowl to stop it chafing and pushing the lower wing out more than it should.

Overall, I'm very happy with the positioning result - but the spot and plug welding had still to be completed to fix the whole caboodle solidly into permanent position, as well as hammering the rear of the lower wing panels over the reinforcing strip. 

I made a start on spot welding the flanges between the upper bonnet and one lower wing panel - perfect access and I used a stool so I could wield the spot welder better - but it was awful. In some places I got perfect spot welds, but in the majority of locations I couldn't even get a spark, despite me using clamps either side of where I wanted to spot to ensure good contact.

At first I thought it might have been the layers of weld-through primer on the outside of the flanges where the spot welder contacts the panels that was causing too much insulation and so sanded that off, but still I couldn't get a current to pass through. I did a test on two pieces of clean, scrap metal with perfect results. 

I tried drilling a tiny hole through the flanges and spot welding on those holes. That worked, but a little too well, burning through both flanges, but sealing around the hole. Not the best method as it eats up electrodes.

A bloody mess!

It can only be the weld-through primer not acting as it should. I would perhaps better have left the primer off and using sealer after the welding, although the function of the weld-through primer is for the welding heat to cause the zinc in it to melt and form a protective barrier around the weld between the flanges.

I moved on to the cowl panels and the result changed immediately - perfect spots till I ran out of reach.

Now, there is one big difference between the areas - the paint in the photo above has had a week or more to dry, meaning the zinc particles are closer together in the matrix, whereas I'd applied the weld-through primer to the flanges where I was having difficulty only the day before, leaving a lot of crap to dry off thoroughly and shrink. I enquired of the oracle (Google Gemini) and yes, it's advisable to allow the paint to dry thoroughly. It depends on the quality of the weld-through primer and, perhaps, sourcing from e-Bay was not the best idea.

I now want to introduce the concept of magic dust to you. As it happens, I was making some more electrodes for the spot welder, which involves cutting up copper rods into suitable lengths and putting a thread on one end. I was using a disc cutter to chop the rods and managed to make a quantity of what I now call magic dust - fine copper particles. I thought that if I could blow some magic dust into the flange gaps it might increase the conductivity across the flanges, especially as the copper particles were larger than the zinc particles in the weld-through primer. It worked for a few areas, but I didn't have enough and many of the gaps were too small to blow anything between the flanges. As a concept, however, it's quite neat.

I did, however, persist and got the majority of the spot welding done. All that remains is plug welding; however, I think I'll call on the assistance of my mate next weekend.

Once solid, the mudguards can be welded into position and the various struts added. That will complete the upper bodywork and a rotisserie will have to be sourced to attack the underside.

I loosened the engine mounting bolts over the weekend - they were almost solid with rust, but a liberal application of diesel for several hours released them. Not sure whether to remove the engine and gearbox as a complete unit, or just the engine. Both need removing at some stage, so engine and gearbox together seems to be the logical solution.