Chapter 15. Rusty Nuts

Progress has been made this last week, but as with everything in life some jobs are taking longer than expected. I still reckon I could have had a working bike for Mallory but it would have meant a lot of “overtime”. This week has been mainly about the footrests, tank de-rusting (hence the title) and the primary chain guard.

I’ve had a couple of coach bolts in place of the footrests for the last couple of months, partly so I would be able to start the bike, jump on it and not fall straight off, then ride it round the garden, but also they make good supports during construction. It has though allowed me to be sure how I would position the rests and herein lies the problem. I ran the exhaust headers back in line with the lower frame rails, exactly per the standard model, although tucked in a little further. I feel a lot more comfortable with rear-sets and unfortunately this location put the axis of the rests right in line with the rear chain. So, for some time I’ve envisaged a cantilever arrangement from the rear engine-gearbox plate frame lugs, over the pipes to the rests. This realised an advantage in that I could hang the exhaust brackets from the rests themselves. My foot also cleared the clutch drum nicely and I could fit the rear brake lever to the correct frame lug.

When I came to fitting the fabricated rests, suitable for standard BSA rubbers there was just too much flex in the arrangement. I don’t think they would have broken but we all know how important it is to have a firm foot placement when things get exciting. My solution is one of those that I’m not too pleased about but will work for now. I’ve fabricated a tubular brace to go across the frame, over the chain and connect the two footrest supports. Its now solid enough but doesn’t look that “period”.  When time allows I’ll try and get a couple of “U” shaped forgings (there’s a friendly blacksmith near us who’s into bikes) to bolt onto the lugs and run either over or under the pipe.

De-rusting the tank was a job I’d put off for ages, but there was no avoiding it now. I tried the usual method of a few handfuls of wood screws and a gallon of diesel into the tank, sloshed it round over a few days and got some pristine screws out, but made little impact on the rust. Plus, it was virtually impossible to get the last few screws out – in fact some may still be wedged in place. I tried again with a box of coach bolt nuts that have been lying on a shelf for years, and lo and behold shiny nuts, but no real improvement. I thought about Kurust, which works a treat on frames, but there is so much rumour and speculation with respect to petrol and the dreaded ethanol, and what it reacts with I thought best avoided.

Another technique that gets good reviews is the electrolysis method so I’ve gone with this. A bag of washing soda was added to our Sainsbury’s click and collect order. This was made up into a 10% solution (10 grams of soda to 100 ml water) and added to the tank. I used an old solder reel to make a couple of electrodes to go into the two filler nozzles. These were connected via a spare stop light and an ammeter to an old battery and my new battery charger. If you try this, the negative goes to the tank – the part you’re trying to de-rust – and the positive to the electrode. There are plenty of links detailing the method on the interweb. The stop light reduces the amperage to a more or less acceptable level and was a good reminder to me that the power was on. The amount of rust that came off at the first pass is incredible – see pic - but having repeated it three times I’ve gone back to the nuts and diesel for a final swill round.

The final job I’ve tackled this week is the primary chain guard, which is a shame in some ways because I’ve gone to like the raw appearance of the exposed sprockets and chains whizzing around, but health and safety must come first. (Do I get a gold star for saying that?) I have made it from sheet steel, mainly because my TIG machine is a DC type and can’t weld aluminium alloy. 

I always start with a cardboard template and was then able to cut out the whole guard in one piece from 18 swg (1.1 – 1.2mm) mild steel. Having formed the curves I cut some slits to allow for the fold and provide for a lap-type weld joint. For welders like me (somewhere between inconsistent and rubbish) this is by far the easiest weld to get right. Also, for once the steel itself was good quality – I find this is becoming a real issue, possibly the composition, but also the amount of mill-scale which has to be removed. Perhaps this is a result of on-line ordering, with no idea where the steel is made and rolled, whereas a good local steel stockist could be a better bet.

 

 

A shorter chapter this week. I had intended to write about my BMW R80/7 Café Racer, but that’ll have to wait for another time. It looks like Brooklands will be opening again in August, which is great news. I have completed the volunteer survey which I found very useful as a way of expressing my own personal concerns and requirements for going in as a volunteer. The more of us who reply, the better we’ll be catered for if and when we feel we’re ready for it. 

In the meantime, good luck to all for the Brooklands Virtual Motorcycle day this Saturday and Sunday. I know that Martin, Perry, Ian, Tony, Mike, and I’m sure many others, have put a lot of work into this. I guess we’ll all be there in spirit – all you can say is that it doesn’t really matter if it rains or not.

Stay safe and well

Gareth