fizzy
Active Member
Posts: 10
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Post by fizzy on Nov 30, 2015 20:27:54 GMT
To answer your question, (in UK at least) yes you can TIG weld it yourself. You will however have to provide test pieces to the boiler inspector who will in turn look at you dumbfounded and ask what you think he is going to do with them! You could send the pieces away for testing but thats expensive and doesnt prove a lot, or you could speak nicely to the boiler inspector and suggest you make the boiler, then have it professionaly ND tested and present the test cert for the welds to him. Its all down to how one interprets the green book rules. Now on to the actual welding. You MUST use deoxygenated copper - if it isnt then dont even think about it or the welds can and will crack very readily. Filler rod is pure Cu or similar specific for the job. Whilst a lot cheaper than SilSol they are still quite expensive. For a speedy boiler you will need around 300 amps, must be watercooled so you are looking at a 3 phase industrial TIG set (not cheap). The stress calcs remain the same but you dont need to flange anything, so a redesign of sorts is required. If your set on TIG then it can be done, I for one have moved to steel boilers for 5" and upwards but I would still TIG a 3.5" in copper with Sil Sol tubes.
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jma1009
Elder Statesman
Posts: 5,901
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Post by jma1009 on Nov 30, 2015 20:58:33 GMT
nigel/fizzy's advice is extremely good. nigel has considerable welding experience, and pushing the boundaries with boiler making way beyond amateurs such as me with copper silver soldered boilers!
if wilf (uuu) and i are remembering the same boiler, it was because ordinary copper plate was supplied instead of deoxgenised copper plate even though a TIG weld was specified and professionally welded on the barrel.
the other problem that arises now is that many boiler inspectors dont like a coppersmith's silver soldered joint on the barrel seam if rolled up of copper and silver soldered and prefer instead an additional butt strap.
Willy, if you cant be certain your copper for your Speedy boiler is deoxygenised stuff then you can forget a TIG weld.
cheers, julian
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Post by GWR 101 on Nov 30, 2015 22:56:01 GMT
Hi Doug I have enjoyed reading your build thread, firstly let me say that I didn't make my boiler mainly because I do not have the skills or the equipment, however I might consider undertaking this in the future. Anyway back to my question I notice that you are considering a strap on the outside to join the barrel, can I please ask why the outside as my boiler has the strap on the inside and is stamped along the seam "STRAP ON INSIDE". As it has passed it's twice hydraulic test and is marked with all the necessary stamp marks I assume that this is an acceptable method. Does this not make the fitting of insulation and cleading more straight forward. Regards Paul
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Post by ejparrott on Nov 30, 2015 23:21:26 GMT
It makes little difference whether the strap is inside or outside. Our John Ellis Netta boiler is also strapped inside and stamped 'strap inside'
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Post by Doug on Dec 1, 2015 7:23:45 GMT
Hi Doug I have enjoyed reading your build thread, firstly let me say that I didn't make my boiler mainly because I do not have the skills or the equipment, however I might consider undertaking this in the future. Anyway back to my question I notice that you are considering a strap on the outside to join the barrel, can I please ask why the outside as my boiler has the strap on the inside and is stamped along the seam "STRAP ON INSIDE". As it has passed it's twice hydraulic test and is marked with all the necessary stamp marks I assume that this is an acceptable method. Does this not make the fitting of insulation and cleading more straight forward. Regards Paul Hi It is purely because i have been asked by my boiler inspector to do it this way and i have no problems with that. the strap will be unseen to all but myself on boiler tests so I dont wish to "mess about" with the design too much. i must say i am not looking forward to this part of the build at all, but i have got to get it done or it will never run. i have given the whole of next year over to getting the boiler finished so it should be achiveable. all the best Doug
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Post by Roger on Dec 1, 2015 7:29:38 GMT
Just a thought Doug, but is there room for a strap where the 'I' section beam for the side tanks goes under? Maybe a joggled joint might be better?
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Post by Doug on Dec 1, 2015 15:57:57 GMT
Just a thought Doug, but is there room for a strap where the 'I' section beam for the side tanks goes under? Maybe a joggled joint might be better? Hi Roger like yorself i am going for a slightly reduced dia so i can fit Kaowool insulation 1) to save the paintwork and 2) to keep the water in the tanks cooler as my tanks are going to follow the radius of the boiler like the original, its such a waste of space making them square, and as i have found when running you really cant have too much water onboard or weight for that matter. i have got to CAD the whole lot up and submit it to my boiler inspector so he is completely aware of what i am going to do, just in case i am going to do something that i am not supposed to.
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Post by ettingtonliam on Dec 1, 2015 16:50:51 GMT
nigel/fizzy's advice is extremely good. nigel has considerable welding experience, and pushing the boundaries with boiler making way beyond amateurs such as me with copper silver soldered boilers! if wilf (uuu) and i are remembering the same boiler, it was because ordinary copper plate was supplied instead of deoxgenised copper plate even though a TIG weld was specified and professionally welded on the barrel. the other problem that arises now is that many boiler inspectors dont like a coppersmith's silver soldered joint on the barrel seam if rolled up of copper and silver soldered and prefer instead an additional butt strap. Willy, if you cant be certain your copper for your Speedy boiler is deoxygenised stuff then you can forget a TIG weld. cheers, julian I have to admit to being out of the loop on modern boilersmithing, but can you explain why the coppersmith's joint is now out of favour, it used to be 'the bees knees', and a work of art when carried out by the likes of Alec Farmer
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Post by Roger on Dec 1, 2015 17:20:30 GMT
Sounds good to me, I agree that the side tanks need attention. I don't know quite how much insulation you can fit in because when I looked in the fillers on Bill Perret's locomotive, it looked like the fillers were partially obstructed by the curve of the boiler. I'd love to have 6mm of insulation in there really
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jma1009
Elder Statesman
Posts: 5,901
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Post by jma1009 on Dec 1, 2015 20:36:44 GMT
hi richard,
the barrel longitudinal seam is potentially the most dangerous if a fault occurs.
the traditional coppersmith's joint plus the dovetail variation requires a very high degree of workmanship and a lot of work. if well made and silver soldered correctly there is absolutely nothing wrong with it, and you are quite correct that Alec Farmer used it a lot. however many of us have seen very poor workmanship on this type of joint.
a plain butt joint of the barrel with a strap added over the joint is much easier to make and therefore less troublesome. whether the butt strap is on the outside or inside is a matter of opinion, though i prefer it outside where its integrity can easily be seen. for boiler water circulation the worst place to put the butt strap internally is on the bottom of the barrel. this of course does not apply to an outside butt strap.
Doug, please note that if you fit the internal piston ring to the barrel to throatplate joint it interferes with the bottom tubes, and is also very bad for water circulation. there have been some excellent examples from 'down under' of double flanged throatplates and these can be highly recommended. it would be a significant 'upgrade' to the Speedy boiler and will meet with your club boiler inspector's approval. i do not like the original Speedy boiler at all for many reasons that i have bored Roger with, and we have sorted out what i consider to be a much better 'update'.
cheers, julian
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Post by Doug on Dec 2, 2015 12:30:11 GMT
hi richard, the barrel longitudinal seam is potentially the most dangerous if a fault occurs. the traditional coppersmith's joint plus the dovetail variation requires a very high degree of workmanship and a lot of work. if well made and silver soldered correctly there is absolutely nothing wrong with it, and you are quite correct that Alec Farmer used it a lot. however many of us have seen very poor workmanship on this type of joint. a plain butt joint of the barrel with a strap added over the joint is much easier to make and therefore less troublesome. whether the butt strap is on the outside or inside is a matter of opinion, though i prefer it outside where its integrity can easily be seen. for boiler water circulation the worst place to put the butt strap internally is on the bottom of the barrel. this of course does not apply to an outside butt strap. Doug, please note that if you fit the internal piston ring to the barrel to throatplate joint it interferes with the bottom tubes, and is also very bad for water circulation. there have been some excellent examples from 'down under' of double flanged throatplates and these can be highly recommended. it would be a significant 'upgrade' to the Speedy boiler and will meet with your club boiler inspector's approval. i do not like the original Speedy boiler at all for many reasons that i have bored Roger with, and we have sorted out what i consider to be a much better 'update'. cheers, julian Hi Julian I recall mentioning to you before on this matter of boiler deisign and i am commited to making "your design" which is much better and mor relevent to todays boiler requirements, three super heaters (tig welded stainless into the firebox) 21 tubes in a rounded format (not the LBSC "rows") and a double flange instaed of the deadly piston ring joint that every boiler inspector hates. a couple of extra aditions of late though like the top feed flange on the radius of the backhead (if i am allowed) and quite a few blind bronze bushes for bolt holes and all other fittings bronze bushed silversoldered instead of screwed in (which is not allowed) my crown stays are going to be more prototypical compaired with Rogers, as i want to keep it simple as possible, bit like my self really. all the best Doug
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Post by Roger on Dec 2, 2015 13:37:27 GMT
A small update on the boiler design I sent you, the number of superheaters is being reduced to two. The reason is to simplify connections from the header and the pipes can be routed directly, one per cylinder. It's also easier to get them out. The tube layout is obviously different as a result but details like the double flanged throat plate remain. I'm sorting out all of the fittings first because I'm not sure how it will all look and what's possible on the backhead. Are you planning on using a cast bracket hanging on the top back edge of the backhead for the turret? You can get those from Reeves.
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Post by Doug on Dec 2, 2015 14:03:47 GMT
A small update on the boiler design I sent you, the number of superheaters is being reduced to two. The reason is to simplify connections from the header and the pipes can be routed directly, one per cylinder. It's also easier to get them out. The tube layout is obviously different as a result but details like the double flanged throat plate remain. I'm sorting out all of the fittings first because I'm not sure how it will all look and what's possible on the backhead. Are you planning on using a cast bracket hanging on the top back edge of the backhead for the turret? You can get those from Reeves. i like the idea of just the two radiant superheaters but is it enough to get good superheat? I may stick with three as i already have the large tubes and i am designing a smoke box that can come off forward exposing the wet headder and superheaters for removal it is something i was musing on my last boiler test, thinking wouldnt it be nice if....... surely its an easy job to machine one of those turrent blocks its only a small block of bronze with a flange milled into the top?
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Post by Roger on Dec 2, 2015 18:06:24 GMT
To be honest, whether it's two out five, it will probably work just fine. I'd wager that two radiant types probably work as well as the five non radiant types anyway. I'll CNC machine that block for the turret but I wasn't sure if you wanted to bother with doing that. It's easy enough, just a simple 'part on a stick' but it's a 3D path.
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Post by Doug on Dec 2, 2015 18:19:58 GMT
To be honest, whether it's two out five, it will probably work just fine. I'd wager that two radiant types probably work as well as the five non radiant types anyway. I'll CNC machine that block for the turret but I wasn't sure if you wanted to bother with doing that. It's easy enough, just a simple 'part on a stick' but it's a 3D path. I think it mat be the perfect part to cut my 3D teeth on
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Post by Roger on Dec 2, 2015 21:28:08 GMT
[/quote]I think it mat be the perfect part to cut my 3D teeth on [/quote] Great idea, it will be interesting to see how your CAD/CAM handles that. The only one I've ever used is Alibre so I don't really know what your software is capable of. I don't know how much your professional methods transfer, I just learn the hard way. On my machine, I find a good method is to use say a 6mm ripper to hack out the rough shape leaving about 0.3-0.5mm and then go straight to parallel finishing with about 2% slices with the size of cutter I'm going to finish it with. That might sound a bit odd, but sooner or later you have to get into those tight corners, and that's when you break the cutters. With a very thin cut, working your way across the job, you can get into the corners right away with very little chance of breaking the cutter. I imagine this would take too long in a commercial job, and you probably progress through several sizes before finishing. I'd be interested to know how you very over that issue.
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jma1009
Elder Statesman
Posts: 5,901
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Post by jma1009 on Dec 3, 2015 0:09:32 GMT
hi doug,
i am very pleased you are not following the original boiler design, and the modifications you commented upon will result in a far better boiler. i am not totally ok with Roger's modification of 2 superheater flues and separate pipes (not rejoined at some point before the steam chests) as if one superheater flue tube got blocked with ash it would mean 1 cylinder being disadvantaged. i have a well tried arrangement of 3 superheater flues for medium sized 5"g locos. i dont see any advantage in having more than 3, and if of firebox radiant type will make your loco very good. i dont have any experience of just 2 superheater flues on a medium sized 5"g boiler, though ive driven a few original Simplex's with the single superheater flue - but dont get me started on the original Simplex boiler!
cheers, julian
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Post by Doug on Dec 3, 2015 6:27:53 GMT
its been quite a few years since I worked in a shop that did plastic injection moulding (aluminium tools) and they tended to use about three sizes for 3D contours but then a tool changer makes all the difference on this. I like the idea your describe it makes sense for our machines and time is not really an issue for the programs. most of the machining we do currently at work is only single opps and there is very little 3D plane contouring. They do a lot of radial contours and interpolation but not currently doing much else.
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Post by Doug on Dec 3, 2015 6:31:05 GMT
hi doug, i am very pleased you are not following the original boiler design, and the modifications you commented upon will result in a far better boiler. i am not totally ok with Roger's modification of 2 superheater flues and separate pipes (not rejoined at some point before the steam chests) as if one superheater flue tube got blocked with ash it would mean 1 cylinder being disadvantaged. i have a well tried arrangement of 3 superheater flues for medium sized 5"g locos. i dont see any advantage in having more than 3, and if of firebox radiant type will make your loco very good. i dont have any experience of just 2 superheater flues on a medium sized 5"g boiler, though ive driven a few original Simplex's with the single superheater flue - but dont get me started on the original Simplex boiler! cheers, julian Hi Julian I do think I will stick with three and a common manifold. With the removable smokebox it's all very easily accessible and looks like it will work well. Roger perhaps it would be wise to put three tubes in the boiler so if you change your mind later you have the facility to add another type of superheater all the best Doug
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Post by Roger on Dec 3, 2015 8:36:33 GMT
I'm not sure that leaving one over sized tube open is a good idea. I think it's best to just make a decision and go for it.
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