WW1 Thornycroft restoration

Cel

This is a well known photograph but it is not necessarily the correct caption. E (AUS) 711 'Walking and stretcher-case wounded of 1st and 2nd Division Australian Infantry on the Menin Road after the battle.' The statement about a shell landing is just conjecture, it may have done, but Frank Hurley was known to elaborate his photographs with additions to make them more appealing to his audience.

Thinking a bit more about the track rod, the ball joints would benefit from hardening. The originals were not very hard but that might have been because the surface had corroded away. Anyway, I decided to case harden the new ball joints. First step is to heat them to a bright red using the propane torch.

 

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Sorry, you can't see the glow but I ran out of hands at that point! Once red, they were stood in a tin of case hardening compound, known as 'Kasenit'. This is a grey powder, very high in carbon. The carbon soaks into the surface of the steel locally converting it to a 'high carbon' steel which can be hardened. The balls were then re-heated to bright red before quenching in cold water.

 

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They look quite rough at this stage but a stiff wire brushing soon cleans them up

 

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Track rod next.

 

Steve (Trying to keep up with that Human Dynamo, Ben!)

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Interesting , Kasenit - almost forgotten the stuff , used to use it regular until 45 years ago. I just followed the instructions off the chargehand with any heat treatment. What I do recall is that we never used the method you describe , although I recall it from Technical College. We always "soaked" for a time period, the parts in a furnace (similar to a pottery kiln) (mainly drill-jig guide bushes) , often dozens the same size - so they were rough machined on a Capstan Lathe out of low carbon steel, OD centreless ground and then internal ground, they were always dropped (wired in a bundle) into a water quench , never a oil quench.

I understand you would have used a low carbon to maintain internal strength , just wondering what depth of hardness you expect to have obtained ?

Grind to size would have been after hardening - so we would be aiming max. depth.

Had a Google around :-

An easy way to harden soft, low carbon metals. Kasenit in combination with high heat creates a tough, durable, hardened finish on the surface of metals. Technical Information Notes: # Produces a wear surface (surface hardening) on low carbon steel, low alloy steel, iron. # Non-poisonous, non-explosive. Application instructions (from Kasenit) for Low Alloy or Low Carbon Steel: There are two methods of application. Method A: Heat the work uniformly to a bright red (1650 - 1700 degrees F), remove any scale with a wire brush, dip, roll or sprinkle the Kasenit powder on the component. The powder will melt and adhere to the surface, forming a shell around the work. Reheat to 1650 - 1700 degrees F, hold at this temperature for a few minutes and quench in to clean cold water. This will give the component a completely hard case of uniform character and depth. Method B: If a deeper case is required, then a container for the compound can be used. A discarded can, lid or tray is suitable for this purpose, but care must be taken to burn off the tin coating before use. Completely cover the component with compound and heat to a bright red (1650 degrees F) for five to thirty minutes, depending upon the depth of case required. Quench only the component in clean, cold water unsing dry tongs for handling. Rates of Penetration: After heating the component to 1650 F using method B, # Case depth .005, Time 15 minutes # Case depth .010, Time 30 minutes # Case depth .015, Time 40 minutes # Case depth .020, Time 50-55 minutes

Cor, I was a bit worried when I saw 1700 degrees until I saw the F :blush:

Only used this once, years ago. Chap I worked with just heated whatever it was till it was red hot and dropped it in the stuff, rolled it around, then shifted it to a forge for a bit and then quenched it.

My case hardening is of the 'Method A' type and I only expect a thou or two of case. Might help us, just a little. I don't intend to touch the female parts of the ball joints. They are pretty poor condition really and I don't think there is much to be gained. Also, the one in the end of the track rod is brazed in which would melt if I try to treat it and would have softened when it was brazed. I think we will leave them alone and see what develops. At our current rate of usage, it should see me out anyway!

Steve

Steve has had the good fortune to be in Devon this weekend and we decided that this would be the ideal opportunity to fit the front wheels. They started off by fitting the new ball joints. They were simply knocked into their holes, done up tight and split pinned. All very satisfactory.

In the mean time, Father fitted the tyre size plates, which had fortunately survived.

Then it was a case of fitting the wheel bearings and trying to set them up with suitable end-float. They went through the stores to see what we had by way of thrust washers and the thickest two were selected. These went on first followed by the new bearing and the outer washer. The outer washer had to be bored out to fit over the new main bearing and skimmed to thickness.

Then, after lubricating the components with steam oil, the wheel was simply lifted on and the locking collar fitted and pinned.

The resulting installation was absolutely solid! Steve skimmed another 0.015” from the washer and success! I would mention here that ‘simply lifting the wheel on’ is easier said than done...

The left hand wheel was fitted in the same way although there was a lot of messing with bearings to get a proper fit without the wheel fouling the hub or oil seal. Success was achieved in the end and the chassis lowered to the ground.

The hubcaps were then fitted and all is well.

The opportunity was taken to fit the track rod and set it to length before tightening the pinch bolt.

That has now been removed again for finish painting ready for the final installation.

There are two brass covers to be fitted over the top of the king pins but, unfortunately, we have only one original.

Steve has spent today trying to spin up another but without success.

He will be on here shortly, looking for some advice.

In the mean time, he has fitted some engine parts which Father has painted recently. The valve cap locking bars and the fan mount and drive pulley.

The spinning looks recoverable. Trimming the fractured edge then straightening with a backing stick ought to help.

I can't work out how the guy in

It seems like the starting blank was bigger than necessary, which leaves more OD to shrink.

Wonderful progress! What a boost it must be to see the Thorny back in its wheels, if only the front ones at the moment.

I am enjoying this thread very much and always looking forward to the next instalment.

As you can see in the last photo of post 1756, the oil pipes between the pump, the pressure regulator and the main line alongside the crank case were still missing. Steve had managed to salvage the others but this assembly remained. He had previously made up the tee and union nuts but needed to cut and form some new pipes. These pipes have swaged ends so the first challenge was to work out how to produce them. Father took a trip to our local second-hand tool shop and found a swaging kit.

This is the shape we had to produce.

Steve selected an appropriate tool and had several goes but it roved harder to achieve than expected!

Eventually, he worked out the height to which the tube should be set and by annealing it three times he achieved success.

Next, he salvaged a bit of bent pipe left over from the Dennis fire pump installation by annealing and straightening it. This was swaged and tried in the pressure regulator.

That fitted well but the challenge now was to bend the pipe. To avoid flattening the pipe during bending, Steve made up a pipe bender to be held in the vice. This worked well and the pipe was tried again.

He then swaged and cut the short piece between the pump and tee and this looked very nice.

However, it was at this point that the deliberate mistake became apparent in that the pipe was exactly in line with the fan belt!

A brief curse and a bit of careful re-bending then took place with an acceptable result.

The last piece of pipe was then swaged and bent.

The last part of the job was to solder it up, using solder paint and then a quick clean before fitting it and heading back to Leicester

The last part of the job was to solder it up, using solder paint and then a quick clean before fitting it and heading back to Leicester

so...shouldn`t be long then til you can bang some juice in it.....a video of a bench run would be nice...:cool2:

We don't plan to run the engine until it is in the chassis. Safest place for it!

There is still a good chunk to do on the engine though. The latest item I have been working on is the fan belt. Both the Dennis and FWD have flat belts but Thornycroft fitted vee pulleys. There is no access for an endless belt so it must have a joint to feed it around the pump spindle. The type that was used was the 'Whittle Belt' made up from leather and steel. I have had the great good fortune to be given sufficient to do the job, albeit second hand.

It is constructed of a flat strip of steel with two pegs which engage in a sort of fibre board on each side, faced with thick pieces of leather held together by a wood screw through the centre. When the steel pegs are rusty, they act as a file in operation and the belt soon fails. To prevent that from happening, I dismantled each link, polished the steel, greased the pins and reassembled it.

Two hours later and an original belt to use again.

The reputation of the belt is not actually very good so I will find some modern link belting to keep in the tool box. It is nice to start with the proper stuff though.

Remaining tasks on the engine include the air inlet shroud, HT Lead conduits, magneto coupling, magneto advance mechanism, the water inlet manifolds and, of course, a carburettor. Still a few hours needed!

I've seen some odd chains and belts over the years but never one quite like this one! And its held together with a ruddy wood screw!

The type that was used was the 'Whittle Belt' made up from leather and steel.

Which led me to:

http://www.fiennes.co.uk/Parts/Catalogue/G/GK/GKB010

I wish there was a picture to be sure, it seems remarkably cheap.

Yes, Andy, very! Modern link belting to replace the belt in the parts book described as 'Whittle' perhaps? Worth a phone call. Thanks for the link!

Steve

most unusual belt, never seen anything like it.

don't know if I would be game to use it? keep a modern Fenner link belt handy!

Jake.

Quite right! Nothing like peace of mind!

Now, king pin cover. This was probably a deep drawn article but the tooling is a bit excessive for just one so I determined to spin it. First task was to turn up a suitable mandrel or 'chuck' as spinners call it. I found a nice piece of oak under the bench, hard as hell!

I tried rubbing it with a piece of beeswax to aid the release of the job, should I get that far.

Then it was time to anneal the brass and mount it in place.

A quick rub with some bathroom soap as a lubricant and off I went.

I attacked it steadily, annealing in between pushes until disaster! I broke through.

I trimmed it off and carried on but it didn't go well.

I managed to develop a crease which just wouldn't go away.

Then the edge began to ripple.

I tried to trim it off but it tore up properly and I decided to write the job off to experience at that point.

So, I must have another go. I have gone back to my books and found that it was getting thinner towards the edge because I kept starting in the centre and working outwards. This stretches the material, ever thinner. What I need to do is start at the outer edge and work in as this compresses the brass. If I work both ways, it should maintain its thickness. The book also suggests that at 16SWG, the material is too thick and that I would be better of with 20swg so my replacement disc is just that size.

For a deep spinning, it says that it is a lot easier if one has a couple of intermediate chucks at progressively steeper angles so that I can spin the disc to them and push out any wrinkles before going to the next stage. I have had another rummage under the bench and found a suitable piece of timber to make them so I will try that as well

Finally, I have had the great good fortune to be loaned some professional spinners tools rather than my home-made variety. As you can see, they are much more massive than mine. With 16SWG, I could feel mine flexing and I was in danger of splitting them at the ferrule. I am not going to break these!

I will have another go very shortly and report back on progress

Do you realise that as a consequence of your activities there will be slightly deranged people having a quiet go at this in dusty sheds all over the world!

Do you realise that as a consequence of your activities there will be slightly deranged people having a quiet go at this in dusty sheds all over the world!

Many of the perfectly normal people I know do this :-)

Our friend Roy - who is a "Hobby Woodworker" has just had a go at spinning and as a first attempt, he has spun up a Pewter insert for a turned wooden bowl. A beautiful job and he has made it look easy! His Pewter "blank" was purchased ready-annealed but it is a much easier material than Brass to spin.

Roy is a member of this Forum and I would very much like him to put up his two pictures of the finished job!

Tony

For the extreme draw of your job, what about making up a spinning tool using a heavy ball/roller bearing?

Something like a 3 or 4" o.d. single roller bearing in a forked arm would seem about right.

I would imagine this might significantly reduce any tendency to cut / tear the material - although I guess the lack of friction heat might cause the material to require much more frequent annealing?

Roy's Pewter spinning!

Roy's Pewter spinning!

Off-topic, but when I made a lid for a ceremonial drinking vessel I found:

http://www.pewtersheet.co.uk/ who sell pre-cut circles.