Iron and Chromework
Door Ironwork: Nothing much to say about this except that I decided to Hammerite all the ironwork as I had a pot sitting in the garage that was more than enough to do everything with a couple of coats. Hung everything up and just painted away.
Bonnet Handles: Fitting the bonnet handles and latches was a bit fiddly (what isn't) but nothing too intricate that time and tea wouldn't resolve.
The first thing I did was to verify the bonnet drill markings made by GD. This I did by making a paper template (not a cardboard one.) And not having any "golden" specific reference points that I could rely on as being good for both sides, I creased the paper around the curve of one corner of the bonnet and marked where the factory mark was. Then I used the same template (but flipped over) to see how far the other side's mark was 'off' with respect to the first mark... Spot on!
I could have faffed around measuring from the centre of the bonnet when lined up with the centre of the car but that would have been complicated and fiddly. For this job I essentially just needed to check that the two handles were in the same relative positions, the paper template marking method being foolproof for this type of measuring.
Masked up around the marker hole and marked the shape of the fibre gasket. Then I simply routed out the shape with the Dremel and finished it off with some hand filing.
Bonnet & Boot Hinges: These are a work of engineering art. Couldn't resist them. Quite a straightforward fitting; just trim the spacing flange to size, adjust the hinge spacing with packing washers, bolt the hinge in place, attach hood and boot and adjust as necessary... Job done.
Underdash' Ironwork: This consists of the steering/wiper motor cross-member, dash' support cross-member and three trays.
The steering/wiper cross-member was the main piece to be concerned with, and this had to be fixed in place utilising the windscreen stanchion brackets and bolts. So it was quite critical to get the packing right so as to not create stress on the windscreen uprights or the windscreen fixing screws.
The centre tray was pre-drilled and metal tabs were factory-welded in place for positioning. However, the outer driver and passenger side trays did not have any tabs to rest on, and a method of attaching used by other builders was to rivnut into the tubing. But, I decided to follow the theme of the centre tray and I welded some steel tabs onto the tubing and tapped for one M5 bolt in each. Am happy with this as it means I can remove the trays easily, and I haven't weakened the tubing with unnecessary drilling and rivnutting.
The front of the trays are supported and held in place by just slotting them under the lip of the dashboard; and of which are held in position very nicely.
Fixing the two steering/windscreen cross-member brackets to the tunnel top caught me out as I put the body on before I secured this cross-rail to the tunnel-top... But this will work in my favour if I need to work in this area in the future.
Initially, I drilled the two holes in the tunnel-top expecting to be able to reach under [the engine bay area] to put the nuts on that would have secured the two angle brackets to the tunnel top; but the thin metal sheet on top of the chassis prevented that. So I will put some spacers in to hold everything in place. Not sure if I’m going to use small or large washers yet. I might even put a rivnut in the tunnel-top... I'll decide when I fit the carpets.
Pre-fitting Activities: Made an 'internal' style plywood template for the roll-hoop legs as it was easier to see and judge things using an internal type of template. I also removed the boot lid. I really didn't need to mess up my shiny body shell surface -and it made sense for ease of access
Rear Leg Mounting Bracket: I needed to remove the top wishbone bolt to fix in place the roll-hoop mounting bracket. Took off the rear wheel and I was pleased to find that access to the bolt was really quite good. A couple of spanners and a gentle tap with a hammer later and the bolt popped out. Eased the rear hoop bracket over the wishbone mounting point, ensuring the vertical fixing hole was on the outermost side of the car, a smear of grease on the wishbone bolt and reassembled... Easy!
I decided not to tighten the wishbone bolt up completely because there was some vertical 'see-saw' movement in the bracket. I.e. ~ +-1-2 mm. Not concerned about this as the metal mount is held in position just by the wishbone bolt so it naturally has a bit of play. It'll all firm up and sit square and flush and solid, then I'll tighten up the bolt properly.
Roll Hoop Installation: Working from the underside and from the outermost chassis fixing hole, made a small hole in the body shell directly above the chassis fixing point. This was my reference point.
The roll hoop leg diameters are 51 mm for the main 180o curve; and 38 mm for the rear dogleg, so I will need to drill holes of about 60 mm and 43 mm. This to allow space for the rubber gaiters. Plenty of room for manoeuvre here and the plan is to route-out three small ~15 mm centre positioning holes then centre everything up before going crazy with the Dremel.
Continuing, I routed out the ~15 mm pilot holes, and this was enough to get my finger in to locate the centre position of the chassis fixing points and get my bearings (metaphorically speaking.)
Then I whittled away with the Dremel until I could drop an M12 bolt into each chassis fixing point. This ensured the absolute dead-centre points were always visible [above the floor of the boot] for me to accurately define and mark-up the proper circumference. And for this, I made cardboard templates [of the circular profile] of the legs. These to define the precise circular location for the holes - remembering the rear leg is 38 mm Ø -NOT 51 mm... So far so good!
I levelled the chassis by adjusting the tyre pressures. Far easier than faffing around with axle stands and pieces of packing on an uneven surface (there is no point because, on my driveway, nothing is really flat.)
The next job was to define and drill the three top holes - the seriously scary bit. I put some masking tape on the underside, to mark the top centre-points and used a plumb bob to find the vertically aligned corresponding centre positions of the lower fixing points i.e. the centre of the M12. As I don't have a proper plum-bob I used a key on a key ring connected to the end of a screwdriver with cotton. Marked-up to the centre points on the bottom M12's marker pegs, and, in my humble opinion, this was good enough to align the top to within gnats-hair of bottom-dead-centre.
Drilled six 2 mm holes in the top of the shell (the scariest and most traumatic bit of the whole operation) and threaded the plumb-bob through to check the vertical alignments, then I adjusted where necessary with the Dremel.
Roll Hoops - Hole Cutting & Fitting: At this point in the proceedings I needed to ensure the hoops fitted properly. To do this, I cut the hex' heads off a couple of M12 bolts and attached these headless, threaded shafts to the hoops. Note... the hoop threads are 1/2" UNF but an M12 goes in a thread or two. These 'pegs' functioned as temporary positioning posts and were perfect because I could locate the chassis fixing holes without having to get under the car and faff around with proper bolts and a mirror.
Problem..! I measured the main hoop and chassis holes for alignment and there was a discrepancy of 0.5 cm on both sides... Finally, after an hour or so, I discovered the discrepancy was in the hoops. The spring-back was ever so slightly too severe. The top of the hoop, i.e. the part just after the 180O turn spacing was 30.5 cm, the bottom i.e. at the ends of the legs spacing was 30.0 cm, and the chassis hole spacing was 30.5 cm. So all in all, everything was spot-on and the eventual fit would be perfect with no slop. This all came to light when I was about to drill the top holes. I knew I wasn't happy about 'something' and I delayed and delayed until I finally downed-tools to work out what was going on. This was when I decided to manufacture a roll hoop template to simulate smaller diameter legs. Having this meant I could drill the top holes without any risk of getting it too wrong. I.e. I could locate the top-to-bottom with the error margin of the diameter of half a broom handle.
Drilled the two larger leg holes and inserted my 'Trojan' hoop, and it all aligned up very nicely with the 30.5 cm spacing. So now it was time go crazy with the Dremel.
Masked-up and marked for the larger holes and Dremelled them to 53 mm. Then I dropped the roll bar in (backwards of course) to check the fit and the alignment. Then with the hoop sitting on the top of the bottom of the boot, i.e. with the M12 pegs in place and inserted into the chassis fixing points, I scribed around the legs to accurately define the 'proper' bottom positions. Ten minutes later, all was drilled out and I was using the Dremel sanding wheel to finish and round off the holes... The sound of the hoops dropping in with a metal-on-metal clunk was music to my ears... Excellent.
With the hoop still in place (still backwards) I drew a centre line, 90O mid' 'U' bend to check the centre position for the rear leg hole. The rear [top] hole is the awkward one due to the top angle of the leg; and, as it was a smaller diameter, the margin for error was less... If I messed this one up it would have been an awful lot of work to repair... Messing-up was not an option.
Drilled out the rear holes and all was well. I did though, at this stage, have to insert the hoops (the correct way around this time) but at a slight angle to get them in. I.e. inserting the front first, then the back. This because all the holes were smaller than they would eventually be and the 0.5 mm spring-back difference at the bottom of the legs made things a bit snug at the top entry points.
Dressing the Holes: I marked up for the 'proper' top hole diameters, with the allowance for the rubber gaiters, by scribing around the edge of the circumferences of the legs using a washer as a spacer. Then I removed everything (once again) and tidied things up with the Dremel sanding wheel. Also, I had to take into account the lateral alignment of the two hoops with respect to each other. I did this by putting a straight edge along the front of them to make sure they were both perfectly aligned laterally. Any difference will be removed by putting a penny washer or two under the offending rear leg.
Gaiter Trimming: I placed the gaiter over the end of the roll-hoop to normalise the rubber around the diameter of the leg-end Then I re-defined the diameter of the inner rubber hole by 'eye-balling' what I had to fit the gaiter over. It had to fit snugly around the post. Then it was a straightforward task of carefully snipping away the surplus rubber with a sharp scissors until I achieved a snug fitting diameter i.e. for a not-too-tight or too loose a fit... Not going to fit the escutcheons yet - not ready for that.
Before, During & After
Filling the Hoops with Foam: This, apparently, is to stop the hoops acting as resonators and interfering with the driver experience [as if.] I.e. to not have the chassis's something-or-other resonate up through the hoops and getting on the driver's nerves. So having to take a leap-of-faith, I bought a canister of sound-insulating expanding foam and did-the-deed.
First, I sloshed some water around the inside of the hoop, this to assist with the setting of the foam. And when doing this I found that the rear leg of each hoop was independent of the big loop i.e. no hole between them, so I had to fill them separately.
Filled the rear-leg first. No drama here, just squirted the foam in until it gushed sedately out of the same hole.
The main legs of the hoop were easier to fill but ever so much-more a messy job. Inserted the filler tube and used a J-cloth to create a seal; the intent being to squirt foam in one end until it appeared from the other end. And low-and-behold after a very long minute or two the foam did erupt from the other leg hole.
Escutcheons: - Not ready to fit these yet.
Conclusion: Drilling and fitting the hoops was a very rewarding part of my build; and I'm very pleased how everything looks. However, this activity came with a stratospheric level of self-induced stress... Drilling holes in my shiny polished -and very visible- top surface was not a thing I was looking forward to.