Minesweeper

Is there a connection with the sea?

 

Hi Ian! That is a very kind and generous offer - I will come back to you later by way of a PM if I may!

 

Tony

Tim is contacting you direct, Ian - and thanks very much once again!

Tony

Hi Tony due to their age & condition they will be of no use to me for the intended use as general storage in the Austin.

I was wondering if you boys would like all 4 boxes on permanent loan for display in one of your vehicles ?

Hi Ian! That is a very kind and generous offer - I will come back to you later by way of a PM if I may!

Tony

I thought you might like my little find Tony, it cant be every day that things like this turn up in almost 'as new' condition.

Would look good in the back of a Dennis or Thornycroft

Well, Ian - should you ever decide to move one or two on, then please think of us!

Tony

From your photos it looks like the drum on the NZ starter shaft is considerably eccentric to the shaft. How would that work? Presumably it is not some sort of harmonic ballancer?

 

David

Yes, it is eccentric - I cannot explain it - but better brains than mine will!

Tony

What a wonderful find!

Tony

Tony

 

I read somewhere long ago, that if a little washing-up liquid is stirred in with the flux it will help with keeping the surfaces clean.

I have never tried it. Have you?

Regards

 

Paul

Never tried that one!

Tony

Very interesting Tony & just at the right time. I am about to start silver soldering some brass 'plumbing' on my Water Bowser Restoration but was not sure what silver solder to use ? but now I'm going to try Easyflo No.2 Thanks.

Good luck, Ian! Remember cleanliness is essential - get any oxidation off the bits to be joined first of all and do not touch the joining areas with your fingers again after you have cleaned them - grease from your fingers can upset the apple cart - make sure that you have "bright" metal. Silver solder "flashes over" very easily so anywhere the flux goes around your joint, the silver solder will run. So enough flux - but try to keep it on the areas to be joined. Practice on a couple of bits of scrap first of all - you want the solder to run by getting it hot enough from the work piece rather than melting it in the flame!

Tony

Steve,

 

When you have the time, I am sure that many of us would like to know your experience with silver soldering/brazing. Do you use the same rod type all the time or do you select a rod depending on the strength of joint that you require? Do you find the flow characteristics of different rods and flux types influences what you use? What combination do you normally use and does it differ for ferrous and non-ferrous parts?

Barry.

I guess that Steve will not have picked this one up yet, Barry - so perhaps I can have a go and he can come in later when he reads it!

All of our silver soldering and brazing experience really stems from our Model Engineering activities - and the construction of miniature steam locomotives in particular, and especially their copper boilers and boiler fittings. So much we have learned from reading and picking the brains of others who have had the experience and where we have learned from our own mistakes!.

We have only ever used propane as a source of heat - the copper boiler on our narrow gauge loco was heated sufficiently - out of doors - with three propane torches on it which did the job admirably. We are about two thirds through with the construction of a similar size copper boiler for a narrow gauge Koppel - about 6 or 7 inches in boiler diameter with a loco type firebox - when it was put aside in favour of the lorries - I hope to pick it up again one day! This was heated up with just one big propane torch but it was well bricked up to conserve the heat and that worked - although now I think we were brave to take that on with just the one torch! The professionals seem to use oxy-acetylene but we are not so equipped and have never used that.

Our favourite silver solder has been Easyflo No2- cleanliness and de-greasing of the items to be put together and a suitable flux is essential for a sound joint. I still have a reasonable stock of the original Easyflo No 2 which had cadmium included in it which seemed to aid easy use of it - but cadmium has now been banned from inclusion in this and the equivalent silver solder now is cadmium free. It is made by Johnson Matthey and they provide a flux suitable for use with it which comes in powder form and has to be mixed into a cream consistency before use. Just mix up sufficient for your immediate use.

The problem that can be encountered with multiple heatings of the same item is that there is a danger of earlier silver soldered joints on the same item melting and coming apart again - various silver solders are available with different melting points and it has been advocated that if you are doing multiple heatings of the same item so that you can attach other bits to it, then you use a silver solder with the highest melting temperature first of all so that for subsequent heatings, you do not have to take the temperature quite so high to get the silver solder to "flash over". I understand that the melting temperature of Easyflo No 2 is higher on a second heating of the same joint so you do have a small safety margin there.

However, I find that with a bit of care, the same solder - Easyflo No.2 can still be used for subsequent brazing on the same item - but make sure that any earlier silver soldered joints on that object are well fluxed up again. This is what I did on the two small assemblies for the Governor weights and pivot - when those two assemblies were put together, they were in such close proximity that there was certainly a danger of the earlier silver soldered joints coming apart again!

We have used this same method on brass, bronzes, copper and steel and have had no problems. We have found it to be a great method of attaching bits!

I am sure that others reading this will have had more experience than us and I shall be pleased to read any other contributions and have the benefit of their experience!

Tony

I'm concerned that you may have to fit much more powerful springs due to the whole assembly now being made of steel rather than steel weights on a lightweight (Mazak or similar) frame.

 

(Not that I have any suggestion as to how it could be re-made in Mazak, of course, though "lost wax' casting might be an option.)

 

On the other hand, this project is still a brilliant example of the machinist's Art.

 

Chris

Yes - we have thought of that one and Steve has been doing some calculations to take that into account. I am not sure how far he has reached with it and no doubt he will come into comment!

Tony

Retired Bank Manager! Never wanted to work in a Bank - wanted to be a Marine Engineer but failed medical 58 years ago because of poor eyesight when standards then were obviously higher than they are nowadays! Spectacles now are not an obstacle. Ended up working in a Bank through default as I did not know what else to do - my exam qualifications were not too special! It worked for me as apart from National Service, stayed with the same employer all my working life! Had the best days in banking before the whole banking culture changed.

If you guys want I can ask around at my company TWI as some of the PHD's might have some ideas on what causes it or maybe how to reverse it? We get involved in a lot of welding research

Thanks, Mike - it would be quite interesting to hear what experts have to say about it - but we are quite resolved now to making a pattern and casting a new one. We understand that old aluminium castings - this one is about 95 years old - were generally made in a poor quality aluminium which does not weld well, even when it is clean and this one being porous has soaked up a lot of "muck" over the years which makes it even more difficult. On top of that, there is sign of wear through "belt rub" so it really has seen better days.

Nevertheless, we always want to learn and will be most interested in having an opinion from the professionals!

Tony

Were those bird droppings on the water pump housing from a MIG pigeon or a TIG pigeon?

 

Barry.

Sorry Barry - I didn't answer this one earlier - it was TIG Pigeon!

Tony

Looks like a bigger workshop might be useful? Here's the engine repair shop at 3rd Heavy Repair Shop (358 Coy ASC) at St Omer

 

If only!

 

Tony

Those liners look huge. Seeing them being placed in gives a good idea of the scale of this engine. Im used to seeing tractor cylinder liners much smaller than this of course.

I'm surprised you have filed the liners flush with the top of the block. It is common on vintage tractor engines for the liner to finish proud of the block by several thou and the fire ring of the head gasket to accomodate this projection. What sort of head gasket will you be fitting to the Thorney?

Steve can reply properly to you, Norman - but don't forget that this is a fixed head engine and you are looking at the bottoms of the blocks!

Tony

Thanks for all the kind wishes for Christmas and the New Year from everybody - which are very warmly reciprocated!

Tony

 

Tony,

At a guess from the number, 1944.

Thanks Richard! Interesting find.

Tony

Well done, Dan! You are certainly going for it!

Tony

Hi Simon,

That was a GS (General Service) trailer, made by Eagle Engineering. A contract of 2,300 trailers yours is the 4th from last in the batch. The Census number, first figure should be a 5, making it X5867297.

What sort of age is it?

 

Tony

Obviously a vast and fascinating subject - and I guess that most of us know very little about it. I hope that all the records of it are safe for the benefit of future generations.

Tony

Thanks Rod - most interesting! I am not familiar with the abbreviations "DAP" and "DSC" - can you elaborate for me please?

Tony

The export of the two "Thornys" in the middle of the Great War to Australia really is quite interesting! Australians took a significant part during the conflict - but I always assumed that any motor vehicles supplied to them were probably given to them when they reached "over here". It would seem unlikely that the lorries would be sent to Australia and then brought back here again!

So were these two - and only two in this consignment - sent over perhaps for training or familiarisation purposes - so that Australian forces knew what to expect when they reached Europe?

The sort of question that Roy Larkin might be able to answer - if the answer is not available from one of our Australian friends!

Tony

Couldn't the steel roller have been set in the mould as a permanent core and cast in? After all the alloy / Zamak is a lot lower melting point than steel.

The cooling rate of the alloy may have been controlled to reduce cracking as it shrinks around the end pins of the roller. I suspect a lot of stresses may still hav been present and hence the later failure of the castings.

Keep up the great work and excellent reports again.

Great minds think alike! Steve has just come up with the same conclusion. The Yoke is of zinc and is low temperature stuff - so yes, it was cast in, in situ!

As was the other steel part with the "eyes" in it to hold the spring ends!

Tony

Evenin gents,

 

what a great piece of engineering to work on, can you tell me how the "roller" looking piece is fitted into the alloy/zinc yoke, I can't see any split or loose shaft, also will you have to get the weight of the new fab the same along with spring tension for the correct governer effect ?

 

 

Andy

1925 Napier Lion x2

1913 Chalmers

That one is on my mind at the moment, too! The only way that the "Roller" could have been put in is by "springing" the yoke and the material that it is made of certainly does not lend itself to that! Perhaps that is the reason for the cracks in the original? We shall not have that problem with the replacement fabrication as the Roller can be inserted before final brazing of that part.

I have also been thinking of the weight of the replacement in operation if it is made of a different material. You may have read that Steve favours "steel" but I was more inclined to go for "bronze" - something for us to discuss when we get together over Christmas! My initial thoughts are that it will make little difference - but we shall see!

Tony

I think that there was a British Dealer bringing these American La France Fire Engines into the UK, some years ago, and then converting them into Edwardian Look - alike Racing Cars - something like Chitty Chitty Bang Bang. There was one for sale at the Beaulieu Autojumble some years ago at something like £80,000!

Tony