FH - pillion footrest

This post is to show you how the most simple small problem takes up and inordinate amount of time. You will remember that I mentioned that one of the pillion footrests was damaged and that the screw wouldn't go in. Here's the footrest mounting I'm talking about:

There is or appears to be a burr on the left hand side of the hole. Actually the whole footrest mount has suffered an impact from the left and the hole is distorted. I spent some time with the Dremel and a small grinding bit removing the burr and relieving the hole on both sides. The screw still wouldn't go in and I resolved to take a slightly different approach:

The new approach was to take the screw and stick it in a collet in the lathe and relieve the diameter of the head by a small amount, leaving the original diameter on a millimetre or so of length so that the outward appearance wouldn't change. This allowed the screw to go into the distorted hole, retain the footrest, and for none to be the wiser.

 

RE Interceptor - chain & sprockets

 A nice little jaunt this evening to see the grandchildren and to help son Thomas replace the chain and sprockets on his 2019 RE Interceptor, supplemented by spaghetti & meatballs to keep us going.

The gearbox sprocket is easily accessible under an alloy cover retained by three screws and the gearchange lever:

The bike has done about 9,000 miles on the original parts and it's high time they were replaced. The tab washer and nut were removed with a socket and breaker bar before we removed the chain. We slackened off the rear sprocket bolts as well. The chain is endless, so we get the Dremel out to slice through a side plate and grind back a rivet:

The rear sprocket is retained by six M10 screws and nuts. This is the new one, bought from Hitchcocks:

You can see the wear on the gearbox sprocket:

All done and back together in a couple of hours. Next stop, tappets and an oil change.

FH - Petrol tank dent repair

 I know I know I know... this bike build has been going on far too long, but in my defence I do have a lot of stuff on. Recently, apart from the puncture I have been faffing about with a press stud on the W/NG panniers, had the carburetter float bowl apart (I must fit a finer fuel filter, the bowl is full of debris and it's stopping the float valve seating), welded up an MZ tank etc. etc...

After several weeks of trying to pull a massive dent out with stick-on dent pullers - I event tried soft soldering one on - I decided the only way I was going to get the dent out was to cut it out, bend the material back to shape and weld it back in. Buoyed with confidence from the MZ TS125 tank, which came out with only two pinholes I decided to go forth with the little Dremel discs:

These discs are one of the best things Dremel make, and the panel was soon out:

Using a variety of tools, including home-made bending irons, adjustable spanners and hammers I adjusted the body of the tank and the panel I had cut out to match a template I hade made from the good side:

I've bought a variety of strong magnets over the years and held the panel in place for tacking:

The plan was to minimise distortion by making short 1/2" welds and letting them cool before moving to a different area, building up the full peripheral weld in short, cool bursts. I started with six-seven tacks:

And ended up with a fully welded panel:

This was dressed back with the Clarke power-file - a 1/2" belt sander, which is proving to be a very useful tool. Next, I closed off the filler neck with duct tape and attached a cycle pump to the fuel tap:

Result! Two small pinholes, fixed in seconds:

Next, Slosh sealant - to ensure an expensive paint job isn't going to be ruined with a fuel leak.

MZ TS125 - Petrol tank rust repair

This is going to be a bit of a leap of faith - my first fuel tank repair. This is an MZ TS125/150 tank from son Thomas and has fortunately been empty for many years, having been stored in the open in someone’s garden - no wonder it’s rusty.

It’s made from two deep pressings, with a third to form the arch over the frame top tube. There appears to have been a butt weld between the two halves, which has corroded to holes. My plan is to take out the whole weld, all the way around, along with a 1/2” strip either side and then let in a 1” strip of 0.9 mm sheet. I make no apologies for mixing units - anarchy is alive and well here in the workshop.

Using the little Dremel discs to cut out the strip makes the job easy. It’s ideal if you can keep the sides parallel, since then you can make a filler with parallel sides and have a minimal gap which will require minimal filler material. 

I held the sections in with magnets while tacking up:

The first section went in OK - I welded in short sections to avoid overheating the material and causing distortion:

It’s quite a slow job, but if you make sure you have a good position as you weld it’s not too difficult.

I used the little belt sander to clean the welds back:

Not a bad result, though it will need a skim of filler:

Pressure testing revealed two pin holes in my welding which were easily fixed. More worrying is a further pin hole behind one of the brackets, which is completely inaccessible and looks like it might turn into a bigger hole:

I’m going to use a tank sealant to fix that. More later.

On with the Oil Tank

Looking back, I realise that pulling those dents out cold was never going to work. The last time I did something like that, I welded the pins in and pulled the dents out hot.

Ho hum. With cracks like this, there was no going back:

So now you are all going to find out what the oil tanks looks like inside...

I decided to do what I should have done all along. Using the trusty hacksaw, I cut down each side of the damaged area. Using a cut off wheel in the Dremel, I cut a short slot, long enough to allow a hacksaw blade to pass through, in the long edges of the damaged area. Then I used a hacksaw blade to remove the damaged area:

The tank is made of 18 SWG sheet. So, taking a piece of cardboard, I cut a template roughly the same size as the hole and attached a loop of masking tape to it. I folded the edge of the card to allow it to fold around the edge of the tank. I then suspended this in the hole and drew around the inside of the hole, onto the card. I now had a card model of the repair patch I would need.

The shape was then transferred to a piece of cold rolled 20 swg sheet, and cut out with the Wiss aviation snips. I folded the edge in the vice, and then used some scrap material to press the joddle into both edges, so that the pieces would sit flush with the original surface:

I've shown it here, held in place with magnets. At this point it is important to dress the edges of the tank, take out any wobbles or dents and make sure that patch sits flat. This is not good enough:

All adjusted; and the butt joints at the short sides have been given a 45 degree weld prep. The panel is tacked in place with the MIG:

Fully welded. a bit messy in places, but I blame the lighting. The lights in my shop are either behind me when I am welding (so I am welding in the dark, with the lights shielded by my body), or if I switch the overhead lights on the sensor in my helmet picks up the brightness and darkens the lens - welding in the dark again:

Dressed with the flap wheel:

There was another weld/dress step as I tested the tank. I filled the tank with water (after it had cooled) and found several holes; these were welded & dressed; I now have two very minor holes left, but the family are complaining about the noise the grinder is making so I had better stop.

Sharpie rings mark the holes!

A couple of days later in a marvellous week at home - I have not travelled anywhere and I have the luxury of a wonderful wife who brings me Martinis in the evening - I'm done with the oil tank. It has taken two more leak test/re-weld/grind cycles to get the tank water tight, but now the repair is invisible as the day the tank was made.

A temporary coat of black hammerite, until we are ready for Phase 2, and we are finished.

Shrinking & pulling

After the gearbox was back in, I decided to have a bit of an interlude and sort out some of the fabrication jobs that had been knocking about.

Finding myself with a spare hour or two one day, I made a start on the dent in the oil tank. The tank has had a major league ding in it for some time. Some was on the AOMCC forum suggested it may have been a battery explosion - it looks more like someone has used it for target practice.

Taking inspiration from a good book 'Building Budget Brits' I decided to use a method involving brazing & pulling to remove the myriad of dents in the tank. Some of them were very deep & localised, clearly with a lot of stretching going on. Now I could have filled or lead loaded this tank and avoided all the work, but I'm keen to learn and try new things....

So the idea is, we pull the dent out without holing or cutting the tank by fixing a suitable stud, wire, piece of scrap to the bottom of the dent and pulling it outward. I'd hoped to be able to weld to the tank and to pull the dents out with the tank hot, much like I repaired the breather tower. However, I was a bit concerned that I might just end up holing the tank, weakening the area around the weld and pulling or tearing the material.

So I elected to braze plain steel nails into the bottoms of the dents and pull them out cold. This would be OK, because during multiple brazing operations the material would be annealed several times. Then, I put a steel bar across the panel being worked on, to act as a fulcrum for the pulling operation. I used a pair of combination pliers to grip the nail and pull the dent out.

So here is the first pass

Nails resited, here we go for the second time..

and a third attempt

and again - four times now...
So before the fourth attempt, we had created several 'peaks' to go with the considerable troughs already in the tank. Levelling the peaks gave us an opportunity to lose some of the stretched material, by locall heating (bright red) in the area of the peak and reducing the height with some light hammer blows.

This is almost at a stage where we could use some filler... Lead maybe...

But, reasoning that this was going well and I could get more of that dent out, I pushed on with a fifth go at shrinking & pulling. This was lower but more level until i cleaned the flux off and I realised the 50 year old steel had cried 'enough'! Take a close look at the picture and you'll see a lot of cracks have appeared:

I think that this is due to hardening. Of course, annealing or normalising steel has a time element to permit removal of stress and changes in the grain structure and of course cooling this thin material happens very quickly. Added to that, the material was obviously thin from 50 years of corrosion.

Max was very concerned:

Still Cold Outside

So we have to find another job that will  bring us indoors.

I don't have many of those left now, but one thing I haven't touched is the oil tank.

Its the right tank, but it has a number of problems:

1. The filler neck is bent, and the thread damaged on one side. It looks as though some clumsy oaf has dropped it neck down on a hard floor.
2. The breather connection is bent, caused by said oaf probably in the same floor-dropping activity. The picture above shows this one, and the filler neck, though I had started work on it when I took this shot (as witnessed by the 38 mm socket acting as a former)
3. The filter is missing
4. There is a hummungous dent in the side that is hidden by the battery

The first of these little gems that I tackled was the damage to the filler neck. The bend was on one side and had splintered the crests of some of the thread away from the base material. Looking closely at this I decided that the material must be relatively hard, so I elected to normalise the metal.

Normalizing is the heating of steel to above its critical temperature followed by cooling in air. The piece is usually left somewhere warm. Normalizing is a quick method of softening a piece to the point where you can harden and temper it for use for your chosen purpose.

I used the trusty Rothenberger Superfire 2 to heat the area to bright red, and played the flame at a distance to bring the temperature down as slowly as possible.

Then, using a large socket in the vice, I placed the neck over the socket to use the socket as an anvil. I used a 38 mm socket, which supports the neck nicely and is a close fit.

With the material cooled & annealed, I was able to push the bent neck back into shape with a variety of drifts & chisels. This went very well, which just left me with the thread to fix.

I did this in two stages, possible needlessly. I started by grinding out the damaged part with the Dremel, since it was confined to about 15 degrees of the full circumference and maybe 6-7 pitches. I cleaned it up using a 1/2" CEI plug tap as a chaser.

Looking backward, I could probably have saved more of the original material if I had started with the tap. Still, the cap will now happily go all the way down to the seal!

The next job I had to tackle was the breather tower. I had a very good picture of what this is supposed to look like from (The Ever Helpful) Brenton Roy of the AOMCC.

As you can see from the pictures, the delightful minaret shape of the breather was a pale shadow of it's former self after the short bungee-less jump onto the garage floor, and I was afraid that much grief provided by attempting to cold form it back into shape would:

• Squash the tube flat
• crack the material of the 'minaret'

So, I figured some hot work was called for, though at this point I hadn't decided if I might do this with the breather detached from the tank. Holding the tank by the lower mount (so I could pull up on the breather connection) I heated the breather bright red and held the little tube in a mole grip, with a suitable rod (actually a masonry nail).

I found that the tube would move from side to side quite easily once the material was hot enough, and this with some upward pressure was enought to roll the minaret up and out of it's inverted position. A couple of cycles of this and it was back to a very passable representation of it's former self.

Next job: the dent in the side.