oldnorton
Statesman
5" gauge LMS enthusiast
Posts: 706
|
Post by oldnorton on Apr 12, 2019 20:24:16 GMT
That's a lovely piece of work Roger.
I liked the previous attempt to fill the copper with TIG heat - I've been there! Some metals tolerate that but the more pure they are, the more troublesome perhaps? I do find that filling holes (in steels) is relatively straightforward with MIG, and then melt it around with the TIG if wanted.
I agree that a mask like tippex is the answer for neat silver soldering.
Norm
|
|
|
Post by Roger on Apr 12, 2019 22:06:20 GMT
That's a lovely piece of work Roger. I liked the previous attempt to fill the copper with TIG heat - I've been there! Some metals tolerate that but the more pure they are, the more troublesome perhaps? I do find that filling holes (in steels) is relatively straightforward with MIG, and then melt it around with the TIG if wanted. I agree that a mask like tippex is the answer for neat silver soldering. Norm Hi Norm, Copper is way more tricky to TIG weld than Steel or Stainless Steel because it just sucks the heat out of the weld area. I could weld that with about 60Amps if it was Stainless but I had to crank it up to 175Amps to even get a puddle. The problem is that when it does warm up, you don't need as much current and it wants to melt right through. I think some sort of pre-heat is what's really needed, but I guess you can't go too far else it's going to oxidise. In an ideal world, I suppose you'd heat it while surrounding it with Argon and get it up to 300-400C I've just looked up some advice and they say not to use such a pointed electrode, perhaps that would have helped too. More experiments required really. I would probably have done well to use a blow torch on it just to get started, but I didn't think of it at the time. If I could get to both sides, or if it was flat then I'd have definitely had a go at it. Blowing a hole in the tube was going to be unrepairable though, so I thought it best not to risk it.
|
|
|
Post by steamer5 on Apr 13, 2019 5:55:53 GMT
Hi Roger, Very nice work!
As an aside, a mate of mine many years ago, had his copper boiler TIG welded, he worked at an engineering company so expertise was at hand, to do the boiler shell I remember him telling me that they added sacrificial two strips out from the shell in line with the join. The weld was then started out on these to do what you described, get the heat / amps in then reduce the amps to do the weld on the shell. The shell from memory was very nice.
Cheers Kerrin
|
|
|
Post by Roger on Apr 13, 2019 7:03:24 GMT
Hi Roger, Very nice work! As an aside, a mate of mine many years ago, had his copper boiler TIG welded, he worked at an engineering company so expertise was at hand, to do the boiler shell I remember him telling me that they added sacrificial two strips out from the shell in line with the join. The weld was then started out on these to do what you described, get the heat / amps in then reduce the amps to do the weld on the shell. The shell from memory was very nice. Cheers Kerrin Hi Kerrin, Thanks for that. I'd be surprised if they did that on all of the tubes though, but maybe they leave them miles too long to provide more metal for the joint. It can all go very wrong very quickly judging by my limited experience.
|
|
|
Post by steamer5 on Apr 13, 2019 8:45:22 GMT
Hi Roger Yes it was only the barrel as far as I can remember. My mate couldn't get tube the size required so rolled it from plate. I agree seeing the issue you are having, TIG welding the tubes & plates in would likely give you an interesting copper sculpture rather than a boiler!
Cheers Kerrin
|
|
|
Post by delaplume on Apr 13, 2019 8:49:29 GMT
|
|
|
Post by Roger on Apr 13, 2019 10:49:41 GMT
Hi Alan, They look very solid. All of the ones I've seen have massive amounts of filler wire, large fillets and huge welded areas around the stays. My guess is that it's not just for strength but just to be able to control what's going on without ending up with a colander instead of a boiler!
|
|
|
Post by Roger on Apr 13, 2019 22:41:15 GMT
I've spent a lot of time today clearing away a multitude of tiny bits and pieces that were cluttering my bench, so now I feel I have a lot more space. Some things that were within easy reach but rarely used have been replace by the opposite, something I should have done long ago. Anyway, I did find time to finish these balance pipe tank flanges, complete with M1.4 threads for the dummy bolts. 20190413_174610 by Anne Froud, on Flickr 20190413_233601 by Anne Froud, on Flickr I also received the 18mm x 3mm cross section 'O' rings for the seal, and you can see the difference in how much more closely the new ones hug the flat sides. 20190413_195836 by Anne Froud, on Flickr I've decided to machine the profile on the ends of the balance pipe to get a nice snug fit in the flange and also to guarantee the spacing is correct. To that end I've modelled this Soft Jaw which is 3D printed... 3D printed fixture by Anne Froud, on Flickr ... like this. I only realised once I'd made them that the cutout wasn't correctly centred, but it doesn't matter, I'll set it up off the ends of the flanges. Rather than clutter up this thread with 3D printing information that won't interest many of you, I've put the process on another thread here. 20190413_162533 by Anne Froud, on Flickr
|
|
|
Post by Roger on Apr 14, 2019 13:48:55 GMT
I've cleaned off the welded tacks and excess Silver Solder so it fitted the fixture better.... 20190414_111738 by Anne Froud, on Flickr ... then gingerly trimmed the top to length using 0.2mm deep cuts and a new cutter so as not to bend the Copper. The 3D model was made so that the top surface of these should end up at 1.5mm above the fixture surface so I can set the depth of the tool. 20190414_121054 by Anne Froud, on Flickr 20190414_133652 by Anne Froud, on Flickr The outside was slightly too big since the Copper will never hug the former perfectly and there's more material on the inside where it's been compressed while forming the shape. It hasn't cleaned up all of the way round, but there's a handy ridge for the flanged plate to sit on. 20190414_141359 by Anne Froud, on Flickr It all rests together nicely, but i'll probably use something to make sure the flanges are held on the same plane while it's Silver Soldered. There's a bit of a ridge in the inside which I might use to support a couple of 'U' shaped pieces of Silver Solder 20190414_143524 by Anne Froud, on Flickr 20190414_143535 by Anne Froud, on Flickr
|
|
JonL
Elder Statesman
WWSME (Wiltshire)
Posts: 2,941
|
Post by JonL on Apr 14, 2019 14:24:25 GMT
I've enjoyed seeing this come together.
|
|
|
Post by Roger on Apr 14, 2019 20:18:56 GMT
The balance pipe flange has a couple of 1mm holes 3mm deep to take a locking mechanism if that proves to be necessary. It may well be that I can support the balance pipe from between the frames but those details are not decided yet. I'll add a couple of attachment points on the underside of the tank to use with this. It's tucked up in a place where it can't be easily seen. 20190414_175500 by Anne Froud, on Flickr I've taken quite a bit of time carefully forming the loop of Silver Solder so it will sit on the very narrow ledge where the joint is required. The wire size is on the big side, but the other wire I have is too small really. I want to make absolutely certain to get enough on there in one go because it's a very delicate setup that can easily move. You can just see the telltale marks of Tippex protecting the 'O' ring mating faces and below in the main tube. 20190414_183158 by Anne Froud, on Flickr This is how it looks before adding the flux... 20190414_183329 by Anne Froud, on Flickr ... and here its completely covered with flux with extra in the area where the joints will be. I've formed some Titanium wire supports for it to sit on rather than on the Thermalite block. 20190414_184413 by Anne Froud, on Flickr I let the flux dry for an hour and then gently warmed it up to make sure all bubbling had stopped. Then I heated the underside of each end one at a time, steering clear of the thin parts that would get hot too quickly. Once it started to melt, I moved over the whole area to finish it off. It only got to a very dull Red heat to finish the job. 20190414_201419 by Anne Froud, on Flickr This is how it looked after just 10 minutes in the ultrasonic tank... 20190414_202542 by Anne Froud, on Flickr 20190414_202614 by Anne Froud, on Flickr 20190414_202558 by Anne Froud, on Flickr ... you can see that there's very little to clean up because the flux has protected it from oxidising. 20190414_202614 by Anne Froud, on Flickr 20190414_202623 by Anne Froud, on Flickr And this is how it looks with a little cleaning up with a small wire brush and fine emery. You can see that it's run a nice fillet just around the joint... 20190414_205401 by Anne Froud, on Flickr ... on the inside too. Although the parts are thin, the combination of Silver Soldering and use of Phosphor Bronze means it's very strong. 20190414_205442 by Anne Froud, on Flickr
|
|
|
Post by jon38r80 on Apr 14, 2019 20:40:13 GMT
Looking at the finished article and the fact that the copper wicks the heat away so fast I can see your choice of silver soldering made it much simpler and cleaner than soft soldering. I think the trouble I have with silver soldering is down to using house bricks as a hearth and not having a big enough burner ( just a plumbers torch) ill have to make a better hearth out of thermalite ( dont like vermiculite its like weetabix) and get a gas bottle for the asphalt roofers torch that Ive got somewhere!
|
|
jma1009
Elder Statesman
Posts: 5,913
|
Post by jma1009 on Apr 14, 2019 21:10:28 GMT
Hi Roger,
That is quite a stunning piece of work! Incredibly complicated and so well executed and documented with excellent pics and descriptions.
Shame it will all be hidden underneath the pannier tanks.
Cheers,
Julian
|
|
|
Post by Roger on Apr 14, 2019 21:20:46 GMT
Looking at the finished article and the fact that the copper wicks the heat away so fast I can see your choice of silver soldering made it much simpler and cleaner than soft soldering. I think the trouble I have with silver soldering is down to using house bricks as a hearth and not having a big enough burner ( just a plumbers torch) ill have to make a better hearth out of thermalite ( dont like vermiculite its like weetabix) and get a gas bottle for the asphalt roofers torch that Ive got somewhere! Hi Jon, You may well be right about the torch, although you don't need a massive one, it's handy to have one because it's a much bigger spread of flame even when it's used more gently. It's also good to get cracking before the flux has a chance to give out. I doubt if it took more than a minute at each end to do, but of course the setup time is lengthy to ensure success. There's a version of thermalite that you can get from B&Q if you can't find that exact brand. They're quite crumbly, but you can saw it which is handy at times.
|
|
|
Post by Roger on Apr 14, 2019 21:24:14 GMT
Hi Roger, That is quite a stunning piece of work! Incredibly complicated and so well executed and documented with excellent pics and descriptions. Shame it will all be hidden underneath the pannier tanks. Cheers, Julian Hi Julian, I'm glad you like it. It's a bit over scale, but not too much as to look that wrong. I wanted to make sure there was an adequate flow between the tanks. As you say, it's not that visible, but I'll know it's there. It's been quite an interesting exercise anyway.
|
|
|
Post by dhamblin on Apr 15, 2019 6:51:15 GMT
Just echoing Julian's comment - excellent write up from start to finish on the balancing pipe. Neat use of the 3D printer as well - scope for more of the same as the build nears conclusion?
Regards,
Dan
|
|
|
Post by Roger on Apr 15, 2019 7:06:51 GMT
Just echoing Julian's comment - excellent write up from start to finish on the balancing pipe. Neat use of the 3D printer as well - scope for more of the same as the build nears conclusion? Regards, Dan Thanks Dan, and yes, I think there's scope for using 3D printing for fixtures to hold tricky parts and also for accessories such as the blower. I might print a test for the shape of the steam dome to make sure that's going to clear the top feeds. I'm also planning of making one of those types that uses a venturi and motor to one side drawing cold air, so the cooler parts could be plastic. Then there's the service kit for the track which could again be printed, lots of places where it might be useful. The printer is more accurate than I expected and the parts are also more robust, so I'm already finding uses for it that I didn't imagine. Better than that is that it's great fun too. I've just ordered the MMU2 (multi material unit) which will allow printing in up to 5 colours. I have no idea what I'm going to use that for, but it looks interesting!
|
|
|
Post by ettingtonliam on Apr 15, 2019 9:09:41 GMT
Roger thats a fantastic piece of work even by your standards. I look at my own efforts and am ashamed.
|
|
JonL
Elder Statesman
WWSME (Wiltshire)
Posts: 2,941
|
Post by JonL on Apr 15, 2019 14:12:53 GMT
Roger thats a fantastic piece of work even by your standards. I look at my own efforts and am ashamed. How do you think I feel on this site!
|
|
|
Post by Roger on Apr 15, 2019 14:40:18 GMT
Guys, it's far from perfect, and you have to remember that it's only feasible to tackle things like this when you have equipment and software along the lines of what I'm using. It would be madness to design something like this to be made by conventional means, it would be a waste of time and probably end in tears anyway.
A bad workman blames his tools, but you also have to give credit to the tools where it's due too!
|
|