Wednesday, 26 November 2014

It might be a car one day!

Despite the lack of updates since my last milestone, I have been making progress in a number of areas on the car.

I have started fabrication of the lower radiator pipe (to the water pump) from a collection of stainless bends and straight sections - this is currently tacked up and test fitted to check the clearances and it is ready for fully welding

Installed the four rivnuts which will hold the fan brackets to the radiator

Test fitted all of the metalwork for both doors (hinges, hinge brackets, intrusion beam, lock mounting etc.), bonnet (‘hood’ for subscribers across the pond) and boot.

Most of these were a simple fit, but I had to adjust the boot hinges somewhat. Unfortunately, the only way to tell exactly what adjustments were needed was to fold my 6’2” frame into the boot, then lift the loose panel into plate (with wedges around the opening to make sure it was centralised). Now inside the boot (along with a torch), I could offer up the hinges to their respective mounting points on the boot and see what needed adjusting. It turned out that I needed to adjust the angle of the mounting plate on the end of the metalwork which involved cutting a slit most of the way through the arm, bending it closed then welding it up. This seemed to do the trick so I could disassemble everything and send them all off to be powder coated along with the radiator fan brackets.

Trimmed and filled the remaining seams on the bonnet, boot and door panels. These are substantially complete, but there are a few areas that need more attention.

Moulded the brackets that will mount the bonnet and boot panel gas struts. These were made by setting up a polypropylene barrier in the four locations (2 on each of the panels) and applying a layer of release tape to the fibreglass skin of the bonnet or boot.

I could then gel coat and wet-lay the carbon fibre tape against the barrier and release tape to create a perfectly fitting bracket.

Once cured, I trimmed to shape and bonded in the threaded metal insert that accepts the strut end ball stud. These can then be bonded to their respective panels along with installing the captive nuts in the bodywork to allow the gas struts to be fitted.

Machined the slots for mounting the windscreen / windshield to the body, along with drilling and tapping the mounting points for the two wing mirrors into the two screen pillars.

After test fitting the pillars and screen though, I have noticed quite a large gap (~10mm) on one side at the bottom of the pillar which tapers to essentially no gap where the pillar meets the body. I need to address this as the mounting bolts will no doubt clamp it up tight, but this will stress the windscreen which won’t do it any favours. I am not sure I can straighten the pillar enough without cracking the chrome plating, so a tapered ‘wedge’ may be required

In addition, given the significant lead time, I have now ordered the trim (seats and carpets) – but you will have to wait until the big reveal to find out what colour(s) I have chosen!

Monday, 20 October 2014

Short post, big milestone!

Short update, but big milestone reached this week. With Herculean assistance from my brother (thanks Neil), we were able to turn the body and trestle around to the correct orientation, then use an engine crane to take the rather significant weight of the fibreglass and dismantle the cradle from underneath. The body could then be lowered into position and with a little pushing and levering, get it settled into its final position on the chassis.

Its starting to look like a car now!

Monday, 6 October 2014

Catching Up

I have been slowly making progress on the replacement bonnet catch. The last update I had made a mould from the region of bonnet inner where the catch would be mounted - I then proceeded to make a part from this mould which would form the basis of the new plug.

I pressed my CNC machine into service to machine some tooling resin to shape which then had to be ‘let in’ to the fibreglass, the gaps closed off and a good fillet of filler applied to the base to minimise any stress from opening, closing and driving vibration. 

This new plug could then be covered in a plug finishing resin, sanded to a good finish with ever finer grades of wet and dry, before the final step of 6 wax coats as a mould release.

I was then able to make a new mould from this plug which needed minimal finishing before it received its own 6 coats of wax

I was finally able to pull the actual part in the same colour as the bonnet itself – quite a lot of effort to get to this stage!

This replacement piece was then trimmed to size and used to mark up for the far more scary job of trimming my pristine bonnet inner skin to accommodate it. With some careful cutting and sanding I was able to get a reasonable fit between the two parts – almost done!

Since fibreglass is not great at accepting the threads for the bonnet catch mounting screws, I had a metal insert machined (thanks Colin) which would be sandwiched between the upper and lower panels. This was bonded onto the upper skin by screwing it to the new piece then mixing resin and micro balloons (tiny glass beads) to make up an adhesive paste which could then be applied to the insert and the whole thing put in place. Once cured, the adhesive held the insert in place well enough to remove the ‘cap’ and reinforce the joint with resin and fibreglass.

The cap could then be finally installed using more resin and micro balloons paste on the insert and all around the opening in the bonnet skin. Quite hard to describe, but the pictures should explain it! Once this was cured, I ground a small groove along the join line, and applied gel coat to fill it in. This could then be cut back and polished to form an apparently seamless joint.

With the bonnet modification complete, I was able to hinge it to the body and install and adjust the bracket which mounts the other side of the catch. This will be getting a cosmetic cover in due course and I still need to decide on the most appropriate position for the release handle along with routing of the cable, but having this job done clears the way for finally mating the body to the chassis!

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!