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WW1 Thornycroft restoration

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It has been quite an exciting day really.. Tim and I pulled the camshaft out and rotated it through 180° yesterday. Unfortunately, he then had to go home but this morning, we were able to put the engi

We haven't balanced the shaft. The rotation depends on how well I drilled the leather so there will be some variability in it. Hopefully, there won't be a problem but if there is, then I will have to

Thanks Tomo. I'll remember that! We have had a nice day., all bright and still and not cold. I have been pressing on with the hand controls and linkage. First part was to cut the throttle shaft a

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To be honest, Barry, I am not sure how the silencer was put together. I cut the steel to allow the ends to be hooked in opposite directions to interlock but that is looking difficult to do and I am told that it would be unlikely at this period. I am thinking along the lines of a straightforward lap joint with rivets but, now that you mention it, the end could have been joggled to give a circular interior. I may have to make a tool to do it. Further thought required!


In the fuel tank, I shall just clean the steel before tinning and not worry about the zinc. It will solder well enough, I am sure. I will tin both sides of each joint before closing the rivets and then simply warm it with the gas torch and feed in a bit more solder if necessary. The proper stuff made of lead this time!


Steve :)


Get one of them joggling tools...the kind that are used for door skinning etc:


Look at this on eBay http://www.ebay.co.uk/itm/302110061842

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Thanks Chaps for your suggestions and kind offer. I don't think that they actally troubled to joggle the edges at this time. Neither the fuel tank or silencer has any cosmetic pretensions and the original tank that I have shows no signs of having been treated this way so I think I will go with straight lap joints and just rivet along the seams. I have some holiday next week and one of the targets for the week is to drill all of the holes in the tank and tin the joints ready for assembly. There are 214 rivets all told!


While we were bending the wrapper one of the miniature railway people saw what we were doing and suggested TIG welding it. Whilst that would certainly do the job, it isn't how Thornycrofts did it. Unfortunately, he couldn't quite see why I would persist with a much more labour intensive method. Oh well!


Steve :)

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Well, the body is schemed out now and the timber has been ordered. There are some big lumps to get for the crossmembers and, as we want to put the body together over Christmas, we need to get some preparatory work done now. In particular, we want to get some paint on the crossmembers and the undersides of the floorboards so that we can just put them together. Painting upwards is a really horrible pastime so getting it done before assembly will make life a lot easier.


To help the job along, I have cut some templates for Mark the Chippy to use. Right or wrong, at least they will all be the same!




I have been pressing on with the silencer tube. I have decided to use just a simple lap joint along the seam so, to drill the rivet holes, I need to pull the tube circular. First job was therefore to turn up some discs and then space them out on some studding.








I pulled the tube together using a torniquet and secured the ends with wires before drilling the rivet holes through both pieces.






These fiendish little devices are called 'Clecos' and I got a bag of them with a model locomotive kit from the US. I just remembered that I have them and thought I would give them a go. They have proved to be wonderful!






Once the hole is drilled, they are inserted using a pair of special pliers to squeeze them up. The ends come through leaving a centre wedge behind. This allows them to be pushed through the plates. When the pliers are released, the ends get a grip on the plate and a strong spring pulls them all together.




Once all the holes had been drilled, I trimmed the edges of the tube to length using an angle grinder. A horrible job but my bending jig for the fuel tank made an excellent stand for the tube to stop it rolling away!




Onec the edges had been cleaned up, they were pulled together and the Clecos inserted once again.




The two rivets at each end were inserted and formed using the rivet squeezer previously prepared for the fuel tank. They went very well.




The remainder were put in using a hammer and rivet snap. This was successful but the snap has given up and split so I must get a new one.








There is another piece complete and ready to fit. It is just awaiting the castings for the ends now so I must pick them up and prepare the patterns which Barry has so kindly printed for us.


A thought occurs to me. How am I going to get the baffles in now that there are 28 rivets in the way!


Steve :)

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They are also referred to as "Nico press swedges"


Thanks for that. It is nice to discover new tools. We have found with these old lorries that you need such a wide range of skills that you are learning all the time and you need your friends to show how each job is done. These Clecos are a revelation and make the job so much easier!


Now, back to pattern making and the top water manifold. The next task is to add core prints to the casting so I started off by turning up some plugs. The timber this time is an old bench top which is a super piece of old pine. So much nicer than MDF!








The other end was turned to a push fit in the casting and was eased in with glass paper. I really didn't want to split the casting by forcing it too hard!




Then the other end:




Attaching a print to the wide end was trickier so I started by sticking a piece of MDF to the face using Araldite.






I laminated and shaped a block for the print.




And this was glued on with wood glue.




A bit of filler to generate some radii followed by a rub down.






Finally, two coats of Bondaprime followed by a polish with wire wool. Then some over-centre catches to hold the core box halves together.




Now ready for the foundry. Sorry the last pic is so dark. I won't take pictures on top of the freezer again!


Now I am onto the fuel tank.


Steve :)

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Why did you join the two halves of the core box together? With them joined I would have thought it would be difficult to ram. Wouldn't it be easier for them to be left split and the two core halves be produced separately and then joined together with core glue? If Bridport use CO2 core sand then the larger exposed surface of split core halves would give quicker setting.



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Hi Barry.


We had a chat about this and decided that they would probably pack it from the ends. However, they still have the option of leaving it open and doing it in two halves so I think both bases are covered. I will get Dad to ask them what they would prefer when he visits the foundry.



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Steve, have you considered making an oddside? I was inspired by your threads on here to make some patterns for the Garrett. I made one handle (a smaller one than this) as a split pattern, but then I was told about an oddside (the part in the middle row, on the right). The idea is that rather than making a split in the part itself, the oddside defines the split; the first half of the mould is rammed up against the pattern, with the pattern in the oddside, and then the oddside is removed for ramming up the second half.


The way we made it was to trace the outline of the part onto a piece of plywood, and then cut out with a coping saw. The back was then filled in to make it sturdy enough for ramming up. It only took a couple of hours to make, and it should make the mouldmaking process easier (and perhaps cheaper?).




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Hi Ed.


Yes, an oddside is certainly the way they will make it (I hope!). If there were going to be a handful of castings then I would make a wooden one. However, for one off, I anticipate that the moulder will make one of sand. In other words, he will place the pattern in a heap of sand and then manually cut it away along the centre line. He will dust it with parting sand and then proceed to fill the box. On turning the box over, he will cut the original heap of sand away, dust it again and then fill the second half of the box before parting in the usual way. The fun bit will be getting the pattern out of the sand as it is quite heavy and I don't want him drilling any holes in John's casting!


We shall see.


Steve :)


PS Nice casting by the way. There is great satisfaction in doing it yourself!

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They are also referred to as "Nico press swedges"


Common amongst aircraft builders


Not quite correct. Nicopress Swagers are used to compress copper ferrules onto wire rope. First used by the National Telephone Supply Company for making rigging cables.


As an aircraft mechanic I use one regularly, couldn't do without it!

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I have had the good fortune to have a few days holiday so I have been working on the fuel tank. First job was to mark the rivet holes in the wrapper for the end plates. I placed the wrapper on a piece of MDF and used my height gauge to scribe around both ends.






Then using every toolmakers clamp that I have, I gradually worked my way around, aligning the end plate with the edge of the wrapper before marking out the first holes and drilling through.






The Cleco plate clamps proved invaluable once again and I am now wondering how I ever did without them!




I worked my way around to the top corners which were much harder work as we hadn't got the bends exactly right. Some care and effort brought the skin around and I drilled a few more holes through.






Both ends brought to the same stage. At this point, I marked where the skin should end.




Then it was a case of trimming off the excess using a disc cutter. Horrible noisy job!




Drill and clamp a bit further to work out where the other end should finish.




Drill the rivet holes for the baffles.




Trim the end off and then mark and drill the holes for the longitudinal seam.






De-burr the inside.




Install the end again to check the fit.








All was well and even the longitudinal holes lined up. Now the challenge of fitting the baffles. These proved exceptionally awkward as, whilst the wrapper was approximately the right shape, it wasn't perfect and getting the baffle inside was very hard prompting a lot of cursing. I took a judgement as to where the baffle was correctly positioned and marked a single rivet hole, removed the baffle and drilled through, then replaced it and put a fastener to secure the position. I marked the other holes on that side and could see that the rear face looked to be in line so I marked them as well. Removed it again, drilled through, replaced it and bolted up again. The other faces were coming into line now so I could mark them and go through the whole performance again. They all worked out OK in the end but it was a very hard and frustrating job which I was pleased to complete!







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Eventually both ends were done to a sigh of relief.




Now, to fit the sump. Father had previously made this so it was a case of spotting through and then cutting out the centre.








Then the filler neck. This is an original casting, rescued from our rotten tank. Again spot through the holes and cut out the centre.




This was done with the nibbler which is a great tool, if hard to guide!






All ready for soldering and rivetting up, my next task!




Steve :)

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QL Driver

I must be missing something, so please explain: how did you replicate the casting numbers so crisply? Regards Doug


Little glue-on plastic numbers for use on patterns Doug, available in a range of sizes as you may expect. regards Gordon

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What a great job on the fuel tank so far, I am sure the result will be more than perfect! I was lucky with the tank on the Peugeot as it was in a fair condition. I only had to seal it with a high quality two component sealer which seems to hold up fine.




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I just visited the Commercial Transport museum in Leyland. I see they have the model of J made by Thornycroft and which was I think on display at the Science Museum some years ago.







The museum is quite dark so I had to use the flash which created a little reflection.

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Little glue-on plastic numbers for use on patterns Doug, available in a range of sizes as you may expect. regards Gordon

Yes, although these were white metal.



We are fortunate that we know what all of the casting marks should be, so we try to put them on when possible.

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Yes, although these were white metal.



We are fortunate that we know what all of the casting marks should be, so we try to put them on when possible.


My employers were cheapskates and used plastic - foundry and pattern work was may day job for many years. When you have mastered 'oddsides' you had to move on to the much trickier 'drawbacks' :mad:

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