Monday, 11 August 2014

Progress and everything!

Despite my lack of updates, I have still been progressing the build on a number of fronts and there is a bumper load of pictures for your perusal!

Since my last email, I have cast all of the wax cores for the intake runners though things were hampered slightly by the first set of moulds ‘drinking’ a couple of cores worth of wax, which meant I had to order some more wax! In addition, two of the carbon fibre lay ups failed to meet the required standard - I managed to blow a couple of holes in the heatshrink which turned out to be unrecoverable after curing so I also ran out of carbon sleeve.

Still, I now have 10 runners (8 good ones!) from which to build up the required manifold parts, though there are only 8 shown in the picture! Unfortunately, they will take a little more finishing than originally hoped due to the less than ideal surface finish from the heatshrink. I will have to wet sand them smooth before applying a finish coat of resin, which will get post-cured along with the bulk of the layup when I melt out the wax.
Onto the body work and probably the most dreaded part for fellow Gardner Douglas builders electing to carry out the finishing work themselves – the engine bay bulkhead. This is where two parts of the moulding meet and the join is usually a gap in the gel coat that needs to be filled.Some people choose to use body filler and paint, but I wanted to use the factory recommended method of using gel coat for a seamless and hard wearing finish.

Things went a little down hill from the start – the first problem encountered was the join itself was not so much a gap as a step in the moulding. Holding a straight edge against the panel showed around a 4mm gap at the worst point!

I persevered though and proceeded to key in the surface and mask off the entire panel with three layers of masking tape. The idea is to apply the gel coat and use the masking tape as a depth stop when skimming the surface then peel it off before curing. The top layer of gel does not cure in contact with oxygen (allows for a better bond for subsequent reinforcement when using it in a conventional layup), so this is removed with acetone before rubbing back the cured material to the desired level and finish.

Given the depth of the mis-match I had to use a number of coats to build up the required thickness, but I got most of the way there. I decided to flat back to a level before applying the finishing layer and this is where I noticed a colour mis-match between the gel I was applying (which matches the body) and the inner engine bay moulding. Apparently they are two similar, but different greys!

Since I would not be able to apply and feather out the correct grey across the whole bulkhead, and after a short bout of tourettes syndrome, I elected to use the body filler and paint approach.

This progressed quite quickly thanks to the warm weather and after a good period for properly hardening, I was able to polish it back to a reasonable finish.

The next job on the list was the footwell extension. This sits on the driver’s side and provides a wider area, particularly for the clutch pedal. This is supplied as a fibreglass moulding which needs to be trimmed and fitted with a peripheral neoprene seal and jack nuts to allow installation. I also elected to paint it body colour, just because I had a can spare from painting the bulkhead!

The only other area in which I have been working is the bonnet catch. I wasn’t keen on using the typical quarter turn locks that are used in the two rear corners of the bonnet, so I managed to track down a (slightly) more modern solution in the form of a unit from a mk2 golf. This requires an addition to the bonnet inner skin moulding to allow for mounting and fastener threads, so I need to make a small inlay of the correct form.

To achieve this, I have taken a moulding from the underside of the bonnet in the region of the new catch mounting and from this I will be able to make a copy of the skin. This can be built up the region in question, before using this as a plug for a new mould. It will all make sense shortly… I hope!

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