Bodywork

My original plan was to start the body in the spring of 2010, but I've started the body early. Because I didn't get a real chance to check out the body pieces before I stored them away, I was curious to see what I had.  I brought down the fenders, doors, bonnet and boot lid from the rafters of the garage. On first inspection, I see a lot of work. On closer inspection I see a whole lot of work.

MGAs use aluminum skins for the boot, bonnet and doors. The frames are made from mild steel. Aluminum is a great for lightness and resisting corrosion, but the mild steel and aluminum are a poor combination. Dissimilar metals in contact with each other can accelerate corrosion. Paint will help block the contact of the two metals, but for my car paint has been replaced by rust.

I've removed all the skins in order to clean up the inside of the frames. I could see no other way to clean and paint the frames.

The corrosion has began to pit the aluminum, but no perforations and these skins should work just fine. Patients is the main tool for removing the skins, and except for a couple of cracks at the seams, I had no real problems. The frames themselves were worse off. 

Sand blasting is the obvious choice, but since my sand baster was tied up for a few weeks I decided to try a different method. Electrolysis uses electricity to clean rust from metal. Basically you need a 12 volt supply (capable of 2 amps of current), alkaline solution (water and washing soda) and an anode (piece of expendable metal). I used a blow up swimming pool big enough for the bonnet frame, added a cup of washing soda.

I used speaker wire with a couple of alligator clips ( don't use the battery charger's clips in the solution, they will corrode). I attached the neg (-) lead to the rusted object and the positive lead to the sacrificial chunk of metal and place them in the solution (don't let the two pieces of metal touch).

After a day you get a soupy concoction.

And the part is rust free, but full of black slimy goo.

After a fairly quick clean up with a steel brush, the results are quite amazing.

99% of the rust was removed and anything remaining is easily handled by the chassis saver paint.

The bonnet skin had a few dents and scratches as well as some holes someone tried to repair.

I didn't want to attempt welding aluminum, specially thin aluminum, so I tried a product call Easyweld. Similar to using solder but a lot stronger. It works on all non-ferrous metals and you only require a normal butane torch (720 deg. f ). The results were satisfactory but not enough to completely repair the damage done.

After cleaning the bonnet skin I sprayed the inside with self-etching primer and replaced the skin back on the frame. I used Easyweld to repair any cracks that showed up in the aluminum seams.

With a very small amount of filler, this bonnet should be ready for primer and paint.

After I completed the bonnet I've discovered that I should have annealed the aluminum before I bent the lip. Annealing is basically heating the metal, it makes the metal less likely to crack and would have made this job a lot easier. 

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