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Post by havoc on Aug 19, 2008 19:52:39 GMT
Largest benefit for me is that welding a boiler is easier in a buildup area than brazing one. Also easier to do without help (or minimal help) as you can first tack it together and then weld a seam. No chance that already joined material will come apart. Assuming you have the right kind of base material you don't need anything else (no silver/flux). Easier handling of the boiler while welding compared to handling 60kg red hot metal.
Anyway, biulding a boiler is always to the current regulation. I think most boiler inspectors let old designs pass but I feel that isn't right. Come with it that it is impossible to obtain imperial sized material, then whatever boiler I want to build is a "new" design. Even if it is for nothing more than going metric. Our code doesn't require calculations to be submitted, but sizes are prescribed so it isn't too hard. Only a dimensioned drawing is needed IIRC.
But the code is a moving target right now. Lots of discussion going on with very little information given to the builders.
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Post by locoworksnorth on Aug 24, 2008 19:37:30 GMT
Whats the technique for welding the internal copper firebox on a full sized locomotive, I have seen them patched and have whole new areas replaced ? The material I guess is arsenical copper and looks about 5/8" thick or more.
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Post by alanstepney on Aug 24, 2008 21:42:44 GMT
Not sure, but when I visited the Severn Valley Railway a few weeks ago, they had a boiler to which they had just made and fitted a new firebox. Copper, 3/4" thick! (I dread to think of the cost.) There were others that had been patched.
I didnt notice any TIG equipment there, but at the same time, wasnt looking for it. A quick look through the photos doesnt show any either. If they do use TIG, it was well hidden on that day.
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Post by ronhancock on Dec 19, 2014 15:41:23 GMT
Hello During the recent discussions with Brozier I've been thinking about how to work on boilers easily. Most people use propane to heat parts but this requires heating the whole assembly (and the world around) to high temps. The next option is Oxy-acetylene. Here we get eextremelyhigh temps, but it's not the safest kit to have around the house and the emergency services won't be happy if anything happens. Of course the half way house is oxy-propane but there are still dangers associated with oxygen bottles - ever seen one get dropped - they go very far! So, I was thinking, could you not use a tig welder as a heat source and then use silver solder as the filler rod. I would have thought this would be even easier if you used fluxed rods. Has anyone tried this? You can pick up a 200amp Tig welder nowadays for just over £200 Hi well just thought i would add to discussion i recently bought an eastwood 200 amp ac dc Tig £608. torch It was great at first but it needed full power all the time even after heating boiler red with oxy acetylene burner. I was happy welding with sifsil copper 985 as welding supplies suggested. I managed to weld my boiler pipes but air cooled torch about ten mins could not hold gun as so hot. I tried to weld the bridges on top of smoke box it finally lost power and could just melt the filler rod. I went on to use my son's works Tig water cooled 350 amp but still had to heat first but welding i found easy. 25 years ago i was a welder might i had but arc gas mig no tig then. i think Tig is the way forward but it hyas to be a very good tig with water cooled torch. welding rods 3 kilo of 985 £120 plus vat lot cheaper than silver solder and you can easy re weld if you did have a problem. If you can see if some one will let you try bit cheaper that way mine i was lucky sent back and had full refund. oh yes the other problem i was having a 9 litre bottle of pure argon i used in a day !!! i turned to to 12 cfm but any lower and would not weld cleanly. good look enjoy Ron
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Post by terry1956 on Dec 20, 2014 10:32:36 GMT
You really need a water cooled tig for welding copper to a good standard. As to the question of time honored ways of doing things.thats find as far as it goes. But times move on and if the hobby is to live then it to needs to move on. Yes there is something nice about doing what others have done before.but lets face facts.the cost of copper, , silver solder, gas etc alone begs the question.are their better ways to make a safe boiler at home.if there is.then this hobby as a body should be looking into it.
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Post by cupalloys on Dec 20, 2014 10:38:59 GMT
Three products made in 100,000s per annum and are 100% copper are water heaters, central heating boilers and hot water cylinders. All the pipework and manifold joints in the first two are brazed exclusively.
In the case of hot water cylinders the side seam is welded. Use CuTiAl alloy with nitrogen shield gas or CuSiMn alloy if using argon. All the other joints to fit the tops and bottoms and bosses are brazed.
Why?
Could it be perhaps the problems of distortion and expansion cannot guarantee the quality of the joint? Try welding a copper tube into a plate. See what happens to any joint gap as you approach the end of the run!
There are several methods of joining two pieces of metal. Brazing comes to the fore when all others fail to meet joint criteria eg strength or corrosion resistance or cost per joint or operating temperature or material combinations or joint design or operator skill or capital cost or production rate.
The brazing process has been around for 3,500 years. It has still got a few years to run!
Weld or braze?
You pay your money and take your choice.
Keith
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Post by terry1956 on Dec 20, 2014 14:43:28 GMT
I worked on copper welding durring my time making MRI scanners. It all depends on the equipment the welder as excess to.to make a copper boiler using electric welding would be a piece of cake compared to using gas and silver solder. I really think that we in the uk our falling behind the times.i was in germany earlier this year and the amount of steel boilers being steamed up far out numbered copper. As to distortion of the weld when using electric, thats not much of a factor why using water cooled welders.michael
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Post by Deleted on Dec 20, 2014 15:29:17 GMT
I did inquire as to the costs of a tig welded boiler for Doncaster at the Midlands ME a few months back, purely as the company involved was there, I certainly hadn't given it much thought before seeing them...probably about half that of a silver soldered boiler...not sure I like the look of the welds around the tubes though but thats purely cosmetic. If I don't attempt to build one myself which with the cost of silver solder is getting more unlikely I may well be tempted to go welded...has a lot of advantages if something fails in years to come,easier to fix without upsetting other joints or at least not such a risk, mind you they come with a long guarantee anyway. I do need to start thinking about the boiler as it won't be long before I need to build things that need the boiler in place....better get some cash then.... Pete
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Post by andyhigham on Dec 20, 2014 20:00:30 GMT
The big advantage of a welded boiler is its repairability. Once a silver soldered boiler is finished and steamed, the chances of a repair is almost nil. If a welded boiler needs repair the damaged part can be ground out and a replacement welded in without danger of compromising other joints
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Post by ettingtonliam on Dec 21, 2014 10:23:25 GMT
Will club boiler inspectors accept welded copper boilers even when made professionally? Is it a case of some will, some won't?
richard
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Post by andyhigham on Dec 21, 2014 11:56:23 GMT
If the club boiler inspector will not accept a TIG welded boiler, I would approach a professional inspector.
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Post by Deleted on Dec 21, 2014 11:57:00 GMT
I asked our inspectors about this a few months ago and they were quite happy so long as they could see the material certificates and the welders qualifications. I don't think a boiler made by professionals such as Steam Technology should be a problem. A DIY job may not be so easy though unless you can prove you are a competent welder of pressure vessels. Probably better to do the prep work yourself and then get it welded by someone with the necessary qualifications.
I'm personally not very keen on the welded in tubes as I think they look a mess and would prefer to see them silver soldered but that's probably just me.
John
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Post by andyhigham on Dec 21, 2014 12:08:57 GMT
Welded in tubes do look slightly "odd" but if you look at it from a different point of view, the effect is not unlike beaded end tubes in full size. I see no reason not to build a boiler with a fully TIG welded shell and firebox with silver soldered tubes. I recently had to scrap a 2" scale traction engine boiler because there were a couple of tubes weeping slightly. The tubes were towards the top and side of the firebox so there was no way to repair it
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Post by Deleted on Dec 21, 2014 12:12:28 GMT
We've been through this before methinks! modeleng.proboards.com/thread/4623/brit-progress-tig-boiler-updateThis HSE guidance should help clarify matters, although somebody is sure to interpret it in a counter productive manner! Those undertaking joining procedures, eg. silver soldering, welding or rivetting should do so only if they are sufficiently competent. In this instance, 'competent' may be described as having a level of practical andtheoretical knowledge that will enable them to produce joints of satisfactory quality and strength. Individuals should know their own limitations and should not undertake joining operations outside their level of qualification, experience or knowledge. Any boiler manufactured in the course of business and placed on the market after 29th May 2002 needs to comply with the Pressure Equipment Regulations 1999 (PER) and should be provided with sufficient documentation to show that it complies - see the Appendix and Further Reading sections of this information sheet. A boiler made in the course of business should thereby satisfy the design and construction requirements of PSSR. Boilers constructed by model engineers, not in the course of business, and put into service for their own use, are not subject to the requirements of PER; although it would be prudent to consider the design and manufacturing criteria within the essential safety requirements of PER, as they contain much useful information as to what is deemed to be good practice. Nevertheless, the design and construction requirements of PSSR should be considered, even though the full application of PSSR to model engineering activities may not necessarily be appropriate.
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Post by bhk on Dec 21, 2014 21:48:55 GMT
On the whole, the idea of amatuer made tig welded boilers made with flangeless open corner welds, with inadequate tig equipment, makes my blood run cold Cheers Paul I say the same about silver soldering, there both a skilled process and both just as easy to get wrong. In my case I could happily put together a TIG welded boiler but would not attempt a silver soldered one.
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Post by bhk on Dec 21, 2014 23:02:43 GMT
So why have so many silver soldered boilers been made to a safe standard in home workshops? Because all you need is common sense and heating equipment. It is also very clear if joints haven't penetrated and need running in again. For tig you will need an expensive set to weld even 2.5/3mm like most things you get what you pay for, argon, and prove you can weld via radiographic ndt testing. Not easy to pass, even for a a good welder. If you have got through that, and flange the plates to give nice curves on the corners (strength) then carry on. Cheers Paul Paul, I just so happen to have all that gear in my garage (and I don't even have a mill) so it's not that specialist and to have a weld test done is about $60. Silver solder is not obvious to be good joint unless you can view the back of it, dare I say I've seen a few modelworks boilers that had suffered a complete lack of penetration of there soldered joints..... Flanged joints are not needed when welding, preparations should be done to the relevant code (ASME IX normally) The point of my post was not to say silver soldering is bad, (that would be far to much of a sweeping statement) but please don't say the same about welding.
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Post by terry1956 on Dec 22, 2014 12:01:14 GMT
I think that the answer here is simple. as with a badly soldered boiler. If a badly welded boiler comes for testing it fails end of. but at the moment all I see is that the hobby will just come to a full stop if it carries on looking down on new ways of doing things. surly part of this hobby is to look at new ways of doing things. Its a bit like saying I will not buy frames cut with lasers or anything made using CNC. the hobby needs to move on, its not 1929 anymore which is the date on the book I am reading by LBSC. michael
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Post by ronhancock on Dec 22, 2014 14:55:41 GMT
I also think we need to look at new ways as Silver solder is like buying Gold now. Also their are very few model Engineers who will make their own boilers. For most to have a boiler made is costly and out of most peoples price range. If we don't want model engineering with live steam we have to look at new ways to bring new members into our Hobby. It does surprise me the nagativity about Tig i recently repaired a silver solderd boiler with Tig. Cleanes with Flap wheel then wire brush on angle grinder. The weld had good penertration. The other point the bad Silver Soldering ie not enough heat i suspect after Tig the silver solder looked Great. I had used Flux on inside just in case it helped and seemed to work. And yes it passed twice the presure when tested. Let's all keep an open mind and help each other please and keep searching new ideas. I had one from a member this week to use a gas valve 8mm for regulater. All stainless with stainless ball should be very reliable and only £5.75 from B &Q. Again two said it will not be a true model i will take the reliability any Day. Ron
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Post by terry1956 on Dec 22, 2014 16:30:49 GMT
Paul.like all thinks people learn. But I feel that unless this hobby moves on from the dark ages.there will be know hobby at all.if countries like germany and Australia can move on in the way of using newer materials like stainless steel etc to make boilers.why our we stuck in the trap of copper and solder.michael
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Post by bhk on Dec 22, 2014 18:49:43 GMT
In a home workshop, copper and silver solder are the best way to make a boiler. It is also when taking in to account the cost of a tig set up to the job , probably the cheapest. So Why change what has been so successful just for changes sake. I havent yet seen a decent reason here to do so. I dont want to take the thread off topic with stainless, so I wont comment on it. Cheers Paul This again is a sweeping statement, in my workshop TIG would be the easiest way, what works for one does not work for all You can rent a decent TIG set up if you do not have one available. I'm not suggesting that if your not competent in TIG that you crack on and build a copper as a way of learning, just like if your not competent with silver solder I would not suggest you learn by building a boiler. I'm glad there are some people out there thinking outside the box and outside our present legislation, and not stuck in a world of red tape.
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