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Post by Nigel Bennett on Oct 10, 2020 16:22:35 GMT
Looking at your plates, which I have to say look very well formed, I would make the suggestion that after every time you anneal a piece, you dunk it in weak acid to pickle it. That way you're working with nice clean material. There's a skool of thought that says that battering a dirty piece of copper batters all the crud into it and it becomes very difficult to clean it up for soldering later. Keep up the good work; I look forward to seeing it running!
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timb
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Post by timb on Oct 13, 2020 14:57:27 GMT
Looking at your plates, which I have to say look very well formed, I would make the suggestion that after every time you anneal a piece, you dunk it in weak acid to pickle it. That way you're working with nice clean material. There's a skool of thought that says that battering a dirty piece of copper batters all the crud into it and it becomes very difficult to clean it up for soldering later. Keep up the good work; I look forward to seeing it running! Thank you Nigel, I had not thought of that. Hopefully I have not done too much damage. I thought I would be OK to clean it all up before soldering and not inbetween annealings, I guess time will tell. I am taking htis slowly to try to limit cock-ups!
Tim
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timb
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Post by timb on Nov 2, 2020 15:53:15 GMT
Well I am getting fed up with Covid now! Just returned from working abroad for a few weeks to find us in lockdown and the club closed for the forseable. I suppose I am not alone but that puts paid to any further work on the boiler until the situation changes. I want to keep things moving along so will work on the fittings for now, most of the rest of the work relies on the boiler being in place so I am a bit limited. One thing I can do is the chimney, this asks for a plain bush into the smokebox casting with a bit of brass tube pushed into it. Spurred on by others I decided to put a bit of rivetting detail into it - first thing is to cut the tube and square the ends, then on to the bush.
This is plain turning from a bit of 1" dia brass bored to match the outside diameter of the tube. A 1/8" square step is included to allow for rivetting. Leaving this in the chuck it was transferred to the rotary table on the mill to drill the 6 off 1/32 holes to take the rivets to the smokebox. Back to the lathe then to part off.... ....and square up the end. Using one of those very handy hex ER collets allowed me to hold the tube with the collar in place. this was a good fit to the tube, the tape there just in case. The hex collet was indexed around to drill all six holes positioned inbetween the first set for appearances sake. All holes done and ready for the rivets. The top is a bit of free hand turning to get a good shape. The complete chimney waiting to be fitted. Feeling a bit better now, a bit of progress. I think I will look at some boiler fittings next. Sorry if this has been a bit basic for some but it is progress never the less. Thanks for looking in! Tim
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Post by coniston on Nov 2, 2020 23:13:13 GMT
That's a nice job Tim, I've recently bought similar blocks for my 5C collets, used the square one almost immediately, very useful bit of kit.
Chris D
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timb
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Post by timb on Nov 5, 2020 13:43:44 GMT
At the risk of boring you all thoroughly, I thought I would carry on with a few basic turning items, the next being the dome. This is not actually a steam collecting dome as such but a means to connect the end of the superheater flue to the regulator, all will become clear later. The dome itself could be made from one lump of brass but as it needs to be fitted to the curve of the boiler I have elected to make it up from parts leaving the flange as a separate item to be shaped when the boiler is finished then silver soldered on.
The body is a piece of brass tube with the ends squared in the usual way. The cap is turned from 1" dia brass with 1/8 step to a push fit to the tube with a 3/16 x 40 hole down the middle to take the superheater pipe which is threaded on during assembly. The tube needs to be a good press fit. I reversed in the chuck, mounting on a mandrel to the threaded part and turned the outside dimensions to size. The fancy shape was then turned by hand and polished. There is a flange to bolt to this so I left a register at the right dimensions. This more or less completes the dome as such. The flange was turned up next 5/8 x 1/8. This is to take a 3/16 pipe so I left the hole at 11/64 to get a good push fit prior to silver soldering. Typically I have no pipe so this is now on order.
The drawing says 4 x 8Ba fixings so I set up to use the square collet block to drill the holes, lining up with the edge of the vice jaws to aid repeatability. Indexing round three times leaves a set of equally spaced 8Ba clearance holes. Without moving anything but changing the collet to fit the dome top I can now repeat the holes for the tapping size knowing that everything will line up perfectly. Each hole drilled and tapped as I went. Just to prove everythig lined up perfectly. The last bit to do was to fit the support arm for the regulator actuating shaft. This is screwed into the body of the dome. Again as the collet was on the centreline of the mill this was a quick job, just measuring from the edge of the tube. The support arm was turned up from some 3/16 ms and a hole drilled for the regulator shaft. This was finished to shape with a file then the whole lot was cleaned and assembled. I was hoping to get the pipe soldered to the flange today but there you go, thats for next time.
This all took about three hours this morning, the square and hex collet blocks are definitely a time saver, I would probably have spent half an hour setting up the rotary table for doing the PCD and then buggered it up by going to the wrong value on the scale. If anyone is thinking about getting these blocks I can highly recommend them!
Thanks for looking in! Tim
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timb
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Post by timb on Jun 21, 2021 10:36:01 GMT
Well its been way too long since I have posted on this thread so now that I have access (limited) to the 'boiler man' I can move forwards a bit. Previously I was pondering soldering the seam of the boiler wrapper without rivets. I secured the lap strip with stainles steel wire twisted together at the ends over a length of ms round to give some clearence. Three lengths were required to secure everything in place. I am sure I took a photo at the time but I just cannot find it. I cut 2 pieces of solder the same lenth of the barrel and placed them inside along the seam and covered the lot, inside and out with flux. I used 1.5mm dia Brazetec 3076 solder - high melting temp and their ready mix 'H' paste. The barrel was set in the hearth with the strip to the bottom, so the solder was inside, and applied heat from the outside underneath. Well this took a while, probably getting on for 10 mins with the torch going full pelt at the end. I started with low heat to evaporate the flux water content and waited until this had gone to a sticky toffee consistency before turning the heat up. The flux consistency kept the solder in place until it started to bubble then I was constantly prodding it back to where it should be with a length of welding rod. The only way I could get a successful melt was to concentrate on one end then work along the barrel with the flame as the solder flowed. I have to say I was quite worried at the outcome as this solder did not appear to flow as well as the old stock I have. I have no idea what grade my old stuff is so did not want to use it on the boiler, only for bits that need joining together where remelting is not a problem.
I need not have worried and was very pleased at the outcome. The photo was taken afer a few hours in the pickle and a rub with some scotchbrite. I tried to continue rivetless with the throatplate but no matter what I came up with I could not get everything lined up suitably well just with bits of twisted wire to hold everything in place so I bit the bullet and put rivets in. These were loose and I made sure there were good countersinks on both sides of all mating parts. Once assembled I coated with flux and added lengths of solder to all the joints, with an extra piece on the inside around the barrel. Again I gently heated the lump up to evaporate the water in the flux. This time I had the boiler shell nested in firebricks and was able to concentrate the heat better. It still took as long but there was considerably more mass to heat up so not as long as it could have been. I used the same technique starting at one end after getting a lot of heat in overall. The results were not bad considering. Here again after a dunk in the pickle (citric acid). There is a little void botton right but I can attend to this when the foundation ring is done. Looks a good fillet on the inside at the sides.... .....and where the throat plate meets the barrel. Firebox next. Thanks for looking in Tim
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Post by philh1aa on Jun 21, 2021 13:53:17 GMT
Tim,
That looks very neat and perhaps you already know this and have a plan but do you also need to surround the rivet heads with silver solder (the inside flange of the throatplate).
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timb
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Post by timb on Jun 22, 2021 9:08:42 GMT
Tim, That looks very neat and perhaps you already know this and have a plan but do you also need to surround the rivet heads with silver solder (the inside flange of the throatplate). Thanks for that, you cannot see it in the photos but the rivets have a good solder ring on the outside - I will ask the boiler man though, just in case.
Tim
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timb
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Post by timb on Jul 10, 2021 12:07:08 GMT
On to the firebox then. I resolved to rivet this together and adopted the loose rivet with countersinks both sides to encourage solder flow. One side (end?) at a time was done with a pickle inbetween. This is the first with the firehole ring peined over and all fluxed up. Outside:
Inside: I was expecting this to take a long time to heat up. Solder placed along the joins on the outside and heat applied from the inside until the solder flowed. In the event it took a relatively short time for the solder to flow maybe one or two minutes. I chased it around the sides and then concentrated on each rivet in turn until I could see a ring of soder on the outside. Here is the first side (end) out of the pickle. Outside: Inside: Rivets: Very pleased with the result, good penetration through to the inside and around the rivets.
Crown girder next and this is where I hit some problems. The stay would not rivet flat no matter what I did, the rivet snap was too long but had to reach up innside the firebox, the copper moved and domed when the rivet was hit meaning that I could only get point contact at the place of the rivets. I persevered and eventually managed to get a good line of solder along the length of each stay, hoewever next time I will do this differently - more of that later. Firebox assembly complete. Next I had to figure out how to get the tubes soldered in, parallel and in the right orientation for the tube plate to be fitted later. I ended up making a clamping system using a spare mag base I had. The tubes were inserted to the firebox tube plate then the smokebox tubeplate then stood the lot on end on a flat plate of mild steel. The mag base clamping arm was then set on this allowing me to position the firebox correctly prior to applying flux. A picture speaks a thousand words they say..... This worked quite well. Rings of solder were placed around each tube and a good amount of flux applied. This was not the greatest idea as when the heat was applied the bubbling flux moved the solder around. I had to use a length of steel wire to keep poking the solder back into place, getting a bit anxious as I could not get all the way to the back of the firebox very well and it was taking a long time to heat up. The eventual results were not bad although a couple of tubes moved and are not quite in line with the others. The photo is not the best but the solder has flowed into a good fillet on the outside and is even better inside the firebox, the boiler man likes it anyway and that is all that matters at the moment. If I make another boiler I will change a couple of things. The girders (if required) will be riveted to the firebox wrapper before fitting the ends. I will also solder the tubes to the firebox tubeplate BEFORE assembling the firebox. It will be much easier to apply solder to the tubes and ensure everything is square. I would then protect the ends of the tubes with glasswool when soldering the tubeplate to the firebox wrapper. Live and learn!! Assembly of the inner to outer next. Thanks for looking in! Tim
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Post by Deleted on Jul 10, 2021 12:09:51 GMT
Lovely work Tim...first class sir...
Pete
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timb
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Post by timb on Jul 10, 2021 12:18:12 GMT
Lovely work Tim...first class sir... Pete Praise indeed coming from you GG!!
Thank you.
Tim
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barlowworks
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Now finished my other projects, Britannia here I come
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Post by barlowworks on Jul 10, 2021 21:21:56 GMT
Who's got his mojo back then.
Mike
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timb
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Post by timb on Jul 12, 2021 10:41:40 GMT
Who's got his mojo back then.
Mike
More like steam envy! Amazing what a trip to the club can do.... Hopefully we will see some more Brit progress soon!!??
Tim
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timb
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Post by timb on Dec 24, 2021 13:16:58 GMT
Hi All! Finally some time in the workshop, this has been at a premium this year, I really need to get to the point I can retire!! On with the boiler then, can't believe its been almost six months!! Assembly of inner to outer, I started with marking out for the crown stays, simple bit of lining up then riviting, or so I thought! Marked out on the barrel then ... Clamped ready to drill for the rivets. I dont have a picure of the rivets for some reason however this shows the fit was reasonable. Fluxed up and packed with ceramic wool to help with the heat. This took a LOT of heat, much more than I anticipated, obviously the mass was there but I did not think there was that much. The results were not bad though, at least not to my eye. I somehow managed to get one of the rivets out of place but not noticeable when filed flush to the barrel! Penetration could have been better but there is a ring of solder all round all four rivets. Spurred with a little success, on to the smokebox tube plate. The fit was good and all the insides were fluxed before being tapped into place. The solder was added then fluxed again, here it is prior to being put in the hearth. I cut a circle out of some ceramic fibre board, again to preserve the heat. This worked very well. Expecting this to take a while (it did) I patiently played the flame around the barrel until things started to happen, then played the flame in the barrel onto each tube in turn until the lot ran in. here the results before pickling. And after. Really pleased, I do not think it could be much better. There must be something wrong elsewhere!!
Happy to have finally spent a day or so in the workshop to move this along, hopefully find more time over Xmas. On that note, I hope you all have a safe and happy Christmas and a prosporous model engineering New Year!! Thanks for looking in, stays next. Tim
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mbrown
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Post by mbrown on Dec 24, 2021 13:29:11 GMT
Excellent work - and very neat soldering. Good to see another boiler taking shape!
Good luck with the next stages.
Malcolm
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Post by simplyloco on Dec 24, 2021 13:45:34 GMT
Great job. Really neat. John
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Post by andrewtoplis on Dec 24, 2021 14:04:36 GMT
Looks great, well done!
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