Building a Locost does seem to be a lot of “hurry up and wait”. So many aspects of the build are interconnected, that if one part holds you up, you can’t do much else. Our next big thing to do is put in the floor. We want to do this next because it’s easier to do with the chassis up side down. However, before putting the floor in you need:

a) the panelling to do it.

b) to drill the holes for the transmission tunnel panels.

We can’t do (b) because:

a, again) we don’t have the panelling.

c) it’s better to put in the brake lines while the panels are out.

So we need to order the brake lines. This requires estimating their length, and selecting the correct fittings for the end. You need to know which fittings beforehand, because the shop will flare the ends for us, but the nuts have to be in place before flaring. To know which nuts you need requires knowing which nuts the brake calipers use. So we need to find brake calipers. Nobody on this planet sells brake calipers. Somewhere in the rant above is (d), (e) and (f).

To be fair, it’s not true that nobody sells calipers. We had a lot of help on the forum to know where to look, and phonecalls to some very helpful people (Midas, Rand Ford and A.T.E.) put us on the right path. Calipers will be got next week, hooray.

To figure out how long our brake lines need to be, we laid “simulated” brake lines using normal fencing wire. This was bent and shaped to the chassis, and held in place with cable ties. We added a few loops here and there which can be lengthened or tightened to provide a reasonable margin for error. We also were cognisant of where the T-pieces were, and made suitable breaks in the wire at these points. Once we were happy with the layout of the wiring, it was removed, straightened and measured.

Our aluminium panels have been bought and paid for, and we hope to fetch them on Tuesday – what a laugh that was. It’s amazing how certain suppliers act like they are doing you a favour. This is an actual quote from the chap at the alu place:

D (3 days after the first email): “As requested in my previous email, please confirm order, price and date of delivery.”

Supplier: “I WILL REPLY ASAP, THANKS SIR”

Perhaps his caps-lock got stuck, or perhaps he just needs a holiday?

Nonetheless, it’s now cut and ready, so when we get it we’ll have a number of tasks ahead of us.

Despite all this procurement hassle, it’s not been complete idleness. The Lobro joints are in the process of being grease-packed. That was a pleasant buying experience, with the supplier flying two tubs of the fancy CV grease (Everon) up to Jhb for us. Very cool – I recommend them.

We’ve also been back to the scrappy (as is apparent from all the pics), for almost the last donor bits. We got our steering column (including switch array and ignition), handbrake and seat runner (hopefully a plan can be made to fit it).

I aim to update the various “summary” pages with what has been learnt so far (diff, steering column, front uprights, brakes) at some point in the near future. I’ve also been playing a bit with blog software options – hence the new picture design. However, I’ll probably be back to the old style in the next post.

B

We’re at the stage where things have to get really hands on before we can make progress. The two major things we need to do are arrange aluminium paneling, and fit the brake lines. Our intention is to do this “ourselves”, without buying the pre-made kit. While this should save us some money, it’s a slow process of finding out all the bits needed, what they are called and where they all go. You can’t phone up a hydraulic shop and say “I want a funny copper-coloured thingy that is part of the braking system”. They get rude. Yes, I found that out myself.

What we have done is bought some more bolts (bolt list will be created) and some rivets. We’ve also got our front wheel bearings. Much advice was given on the forum, with the conclusion that it’s better to spend more to spend less. They are Timken kits, and come quite well recommended. The left and right kits are different (142 vs 168), but the only real difference is that the hub nut for the reverse thread side is a different colour.

The kits include bearings and outer races, hub nut, oil seal and even a packet of grease.

As for the rivets, the chief concern has been the angle for countersinking.

I have read some posts that indicate that the angle is probably 110°, however I thought I’d check. So I took a macro photo with my close-up lens, strongly back-lit to cast a silhouette. Then I upped the contrast and saturation to emphasise the rivet, and measured the angle on the PC. There are probably better ways to enhance the image, but I thought the result looked cool. As can be seen from the picture, the best fit is 120°.

The amusing thing is that none of the hardware stores I called knew about this. The one that the rivets came from tried to sell me a 90° countersink bit, for R180. Nobody else could offer a suggestion on how to perform the countersinking. A comment from a colleague and a bit of googling provided the answer. General purpose metal drill-bits are usually sharpened to 118° – which is close enough. So some form of depth protection will be created (possibly a tube of the right length serving as a guard) and a normal 6mm bit.

Now to order the aluminium and figure out all the right bits for the brake system.

B

There seem to be two schools of thought – high current vs. low current. The high current method just uses a 12V battery charger as a power source, whereas the low-current method tries to maintain the current flow at around 250mA by adjusting the applied voltage. The benefit of the low-current method is that it is more gentle, and should be able to convert “intermediate” rust back into iron metal. This should reduce pitting of the final finish. The high-current method generates a lot more gas, and so might loosen rust better than the low-current method making it easier to clean after electrolysis.

I decided to conduct a test to see if the low-current method was worth the extra effort. This test is not overly scientific (scientific tests take a LOT of effort), but was interesting to conduct.

I select two rusty (but not heavily rusted) bolts that I had removed from one of the wheel stubs. They were cleaned in detergent and ammonia to remove any residual grease.

Then two electrolytic cells were built, using the highly scientific jam-jar configuration. One was powered by a wall-wart at 3V, the other by a car charger at 12V (later halved to 6V to avoid meltdown).

The solution consisted of 3g of NaOH (caustic soda) in 1L water. Internet sources indicate fairly varying concentrations (from 2%, which is very strong, to “a tablespoon per gallon”). I think my solution could be a little stronger, but it really does not need to be much stronger. The concentration does not play a large role in the success of the method, so err on the side of weaker. Be very careful with this stuff – it will eat through flesh. It also reacts exo-thermically with water, so fill your cell with water and then slowly drop the crystals into it, not the other way round (i.e. so there’s lots of water to keep things cool)*.

The current was around 300mA for the low-current cell, and initially about 1.2A for the high-current cell. The bolts were left to stew for about 40 hours. After just 2 hours at 12V I realised it was getting too hot (it was too hot to touch) so I dropped it to 6V (and physics tells us that the current would similarly reduce by half). Even at this level the solution produced a large amount of gas. The low-current solution did produce gas, but not much. The liquid level did drop during the course of the experiment (probably a combination of evaporation and that the gas is produced from the water). Another word on the gas – it is an explosive mixture of hydrogen and oxygen so keep the room well ventilated and away from sparks.

Finally the bolts were removed – this is what they looked like:

When cleaned up, the bolts looked like this:

A nylon nail-brush and a green plastic scourer were the only things used for cleaning. The high-current bolt wasn’t noticeably easier to clean, although it ended up shinier than the other. It also seemed cleaner to start with (whereas the low-current bolt looked almost unchanged from the start).

Careful examination of the bolts seems to indicate that the high-current bolt is more pitted than the low-current bolt. A double-blind statistical analysis revealed that the low-current bolt was indeed less pitted (i.e I asked the missus for her opinion without telling her which was which. I didn’t look at the her or the bolts during this process, hence it qualifies as double-blind).

My conclusion is that the low-current method results in a better final product, with more of the original metal recovered from the rust. I’ll be using this method, aiming for about 250mA.

I also finished construction of my large-scale electrolysis cell:

The anode has been constructed from mild steel, and is supposed to provide maximum line of sight interaction with the subject being treated. When the uprights are back from machining they will be the first subjects.

B

* The author accepts no responsibility for any damage you do to yourself, others, your stuff, small furry animals that live near you, downstream from you, upstream from you, non-furry animals living in the same places or other places to furry animals, furry and non-furry non-animals, squirrels, as a result of you reading and/or acting on the content of this website. Actually, let me know about the squirrels – send photos.

And now it’s late and I want to go to bed. But stuff HAS happened – we have bought some bodywork. How very exciting – this represents the first stage of commitment, and we’ve bought basically the last things we need: bonnet, nosecone and scuttle (that’s a dash section). It’s bright orange, but we may respray it later.

Who is we? Well, it started as an idea between D and B. I’m B. “Ever been to a track day?” asks B. “No”, says D, “but I’m keen”. Several track days later (including a severely scored MX5 rim from the kitty-litter), and “Let’s start a racing team” says D. “Great” says B. “Let’s buy a formula Vee car” says D. “Great” says B. But it looks like a very expensive way to start racing. “What about locost?” says B. “Great”, says D. You get the picture? First we were going to buy a pre-built machine, but we’ve taken a team decision to build our own. Lots of reason are behind this, I’ll elaborate in another post. The point is, we have now got bodywork. Maybe I’ll take a photo.

Oh, another design decision is a big red “Start” button in the middle of the dash. Check us on this later!

Till next time,
B