Build Process - Part 3

When last I set two fingers to word processor, I was at the stage of carving the plug into shape. I am pleased to report that this stage is now complete, and lurking in my shed was then something which looked pretty much like what I had "designed", albeit with a somewhat rough and lumpy surface. The main reason for this is that eventually one will get fed up with scraping away with Surform and sandpaper, and will decide that filling the gaps between the separate layers is an easier option. And so it proved. Normal bog-standard Polyfilla was used, and seemed to present few problems, except the ever-present one of running out just before you finish the job.

At this point it's decision time. If you are proposing to use your plug as the basis for a mould, best stop reading now, because I'm not. I felt it unlikely that I, or anyone else, would want another GTO, and the extra time and / or money involved in making a mould could not be justified. Anyway, at this point you have to decide whether you are going to make the main part of your shell as a single enormous moulding, or whether to do it as two (or more) parts. A single one will remove the problem of joining the bits together, but it will be impossible to separate from the plug without destroying the latter, which might prove to be a problem later on. So I decided, on the advice of gNick (who apparently knows about these things), to do it in two bits (or three if you include the lid). This meant that I had to split the finished plug down the middle again, which was a bit more of a problem than antici...pated, due to the fact that the "head fairing" part had now been stuck on top.

Not for long, though, as due to incompetence, it didn't stick too well. Vast amounts of d/s tape finally cured this. Next the plug needs to be sealed, in order to allow the use of polyester resin, rather than epoxy, as the latter apparently costs only slightly less than Hennessy XO. As "So You Want To Build." points out, there are many ways to achieve this, but I elected to use one not listed therein. First, though, I gave it a couple of coats of emulsion, which I suspect achieved little other than wrecking a perfectly good pair of jeans when I had to get it back into the shed in a hurry following the onset of Rain. Then the major blemishes, holes and pockmarks were obliterated with more filler, and any unsightly lumps, paint runs and dead flies were ground off with a quick pass of the power sander. All of which left a mainly-white half-plug, still with a surface more akin to that of the moon than that of a mirror.

However. THIS DOESN'T MATTER! Well, not much, anyway, for a fairing primarily intended for road use. Heresy to the average composites expert, I know, but there is a way to achieve a reasonable finish and seal your plug at the same time. For this, I am indebted to Nick Redgrave, an acquaintance from the pub, who builds theatre props and the like for a living and has considerable experience of mouldless GRP construction techniques. What you use is aluminium foil, just glued onto the surface. It bridges most of the holes without a problem. Nick recommends 3M Display Mount spray adhesive for this task, but a quick shufti in the London Graphics Centre revealed that the stuff costs over twelve quid for a half-litre can. The local hardware shop had something superficially similar for £3.25, but it turned out to be only superficially similar, as it reacts with the foam. Blast!

So I decide to use up the remainder of the IKEA wood glue first, and then try Copydex. Bad idea. The wood glue is fine, but the Copydex dries too quickly to get the foil in place and smoothed before it sets. Thus you end up with, well, how can I put this delicately? I can't - half-dried Copydex looks the way the contents of Lemuel Gulliver's nose would appear to a Lilliputian. But at least it can be easily peeled off, which is a curiously satisfying thing to do.

Anyway, armed with a suitable adhesive, apply the aluminium foil in fairly small pieces - no more than about a foot long. Apply glue to the back of the foil and spread evenly with a brush - a 1" paint brush seemed to work fine. Then turn over and apply to the plug. Dragging it across the surface into position seems to help get it to stick without too many unsightly creases, and a wallpaper seam roller is used to smooth the whole thing out. It might still look uneven, but because the foil is so thin, even the biggest lumps are still pretty small. Coat the entire outer surface thus, and don't forget to go "around the back" a few inches, to prevent accidental resin spillage from eating the plug. Then give it another layer, to be on the safe side, and possibly even another one after that. Repeat with the other side until you have a Shiny Thing.

The next week or so after this stage was reached were largely spent in attempting to track down suppliers of various useful things required to complete the project. Glass fibre, for instance. You may be surprised to learn that East London is the armpit of the universe as far as suppliers of composites goes, and the nearest place I could find was in Brentford. However, I'd also obtained the product list for Polyfibre, of 18 Wainwright Street, Aston, Birmingham, (whose postcode, phone number and fax I seem to have lost along with their price list), who had everything I required and more. Since the Brentford outfit aren't open at weekends, I needed a day off. And since Polyfibre had everything I needed, and since you can drive from Walthamstow to Birmingham in about the same time as from Walthamstow to Brentford, I went to Birmingham instead. Polyfibre are nice and friendly and, according to gNick, cheap as well. Plus they take plastic money and will deliver. So I lightened my wallet a little further, and then came home.

Next stage is to wax the plug, so you can actually get the GRP off once it's set. You can spend a lot of money on release agents of one sort or another, or you can buy furniture polish in your local supermarket. Apply with a cloth or spray it on. Don't polish it - the aluminium foil is non-porous, so all you will succeed in doing is rubbing it off again. And try to avoid the lavender-scented stuff.

Finally, finally. Laying up the glass. The bottom bit is easy - just a 2.5 m length of 280 g/m² woven rovings with the appropriate bits you want to leave open carefully cut out - in my case the rear wheel opening and the side portion of the lid. The upper part is less simple, as there are all sorts of odd shapes and windows and things to take into account - in retrospect it would probably have been easier just to glass the whole lot and cut the holes out afterwards, rather than trying to assemble a coherent whole out of a patchwork of small pieces. Mix up resin and catalyst, stir vigorously. You will definitely need gloves for this, and probably overalls as well. Also a well-ventilated space, as the fumes from the resin will get you pleasantly stoned. It's better to mix small quantities of resin than large ones, as otherwise the contents of your bucket will suddenly go "GLOOP" and turn into something which you might expect to find 'twixt pastry and meat in a pork pie three months past its "best before" date.

Then splat the stuff on with a brush and, if you have one, squidge down with a roller. Polyfibre will sell you brushes for about a tenth of the price of your local DIY shop. This was the most nerve-wracking part of the process so far, as I had only Nick's word for it that the aluminium foil would work. Not that I don't trust him or anything, but he does seem to spend an awful lot of time in the pub. Anyway, it did work, and as I write this, from my window I can see half a fairing gently setting in what would be the sun if the weatherman had been right, rather than something resembling arch-villain Clarence Boddicker's Number One Sidekick at the end of the first "Robocop" film, which is what I half-expected. Hopefully it will dry enough soon, so I can get on with the second part, maybe even in time for the Holland-Argentina match.

I did, and the following day added a second layer of glass. Next comes Big Fun Part #2 - Getting The Damn' Thing Out. Actually, this turned out to be several orders of magnitude easier than I'd expected. When laying your new tongue-and-groove floorboards, you need to bung little triangular plastic wedges between the wall and the floorboards, and these turned out to be extremely useful for the first stage of separating the glass from the plug. As they're only about 3 inches long, though, you need something a bit more substantial as you work towards the middle - I found a wedge-shaped piece of wood lying around which turned out to be ideal. Once you get even further into the middle, you can use your hands and forearms, though sturdy gloves are a must, as the edges can be very sharp. And after about an hour of hammering, grunting and straining the whole thing just popped out. True, there were a fair few bits of aluminium foil still attached, as the wood glue holding down the second layer hadn't dried fully, even after about ten days. 99% of this was easily peeled off, though. The second side, which had the benefit of a coat of "solid" wax polish as well as the spray stuff, came off more easily. Next, the excess glass was trimmed off from around the edges, using a couple of pairs of sturdy scissors, a hacksaw for bits where two pieces of glass overlapped and cable cutters for the awkward corners. This meant an end to lacerated shins caused by having to store the two halves in the kitchen, as the shed is still full of plug, as I didn't want to start cutting the plug up before I'd got the main part of the shell together, just in case of some horrendous cock-up, like making the lid opening on the left two inches longer than on the right, Yes, I did, though I can't figure out how.

On to Big Fun #3 - Joining The Two Halves Together. gNick said that all you have to do is join the two halves with masking tape and then apply glass to the joint. Easy to say, but when the two halves are wobbly things with thin edges, intent on not sitting peacefully together, well, imagine trying to put Humpty Dumpty together again while all the King's Horses keep giving him a sly little nudge every so often. Experiments with piles of ordinary house bricks were unsuccessful, as were experiments with Tina crawling inside and trying to hold the bits in place while the tape was applied. Then it got dark, and the following day I got home late, and the weather went all manky, and I nearly smeared myself along the Seven Sisters Road outside Holloway nick. And there's the Hayes race, and the start of the Tour de France, and the World Cup Final, and the British Grand Prix, and I have to go and pick up the polycarbonate for the windows from Enfield, and... So the latest Cunning Plan will have to wait until, oh I don't know, later. The photo below should give you a clue, though.