Copper boilers

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GWRdriver

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I'm pretty good, no I'm actually very good, at designing and building copper boilers. I've designed and built over 100 boilers from 1.5" to 6" diameter for locomotives, stationary, and marine engines (all of which models I build for myself) and I'll be glad to advise anyone who needs information and guidance on design, materials, tools, and processes including silver soldering. I can design a steel boiler, but since I'm a terrible welder I don't build steel boilers. It also occurs to me that the Board might benefit from having a seperate "Boiler" topic heading?


SALEY1.jpg
 

Welcome GWR, This is a great place.

I want to build a boilers in the future so I will probably pester you to death when the time comes. :big: :big: I'm slowly learning silver soldering at this time on a small marine steam engine. So far things have gone well.

Ron
 
Diymania said:
Did you come here to gloat ? Kinda seem like it.

No, I came here to offer my experience (45 years of it) to others who might benefit from it, but if that's going to be viewed as gloating then I can find other things to do. I always appreciated having folks who knew more than me to guide me through the maze and the model engineering tradition is to pass it on, but there will always be a few who resent it.

To see one picture simply click on the small photo under my first post. This is a coal fired boiler with an OD of 2", one of a matched pair made for model Climax Type-A locomotives in 1/2" scale for someone in the USA.
 
GWRdriver said:
... boilers from 1.5" to 6" diameter for locomotives, stationary, and marine engines .

Nice! As I'm just getting started in the locomotive-building side of this hobby, I'm interested in seeing horizontal boiler designs. Please post some photos!
 
Vernon,
The gauge/scale of the model will determine what design, or range of designs, should be applied and what material should be used. The smaller scales (Ga1, 2.5"ga, etc) tend to need one set of design parameters and the larger scales (3.5"-7.5"ga, etc) need another. Smaller sizes typically require copper, for good reasons, and the larger sizes may use either copper or steel depending upon several determining factors. These factors could include your skill, capabilities, equipment, and material resources. For instance my silver soldering skills (and equipment) are far superior to my welding skills, as I mention above, so my tendency would be to build in copper rather than steel although steel material would be considerably less expensive than copper. Yer pays yer money and yer takes yer seat.

Since miniature boilers have been made for 150 years, with improvements to technology (and safety) continually being made, there are a lot of well-tried standards which we (those of use who have built a few) use in construction. But as with any technology there are differences of opinion, sometimes great differences, even among the experienced as to what is "best" or even acceptable practice. For instance, perhaps the most active current discussion is over whether stainless steel, which has KNOWN safety issues but is being use anyway, is appropriate for minature boilers.
 
GWRdriver said:
The gauge/scale of the model will determine what design, or range of designs, should be applied and what material should be used...
True. For now I'm just building from plans, and all in 16mm scale, so there's no real "design", other than either "single fire tube", or "teakettle"...but I still like looking at the big stuff; coal-fired multitube with superheat, anything with a real backhead. It's fun to dream, anyway. ;D
 
Vernon said:
It's fun to dream, anyway.
Without getting too smarmy I would say that every next project starts with a dream. All mine have, and I took it one step at a time. I would disagree that there isn't much design in 16mm or other small scale boilers. Most of them start out as a problem looking for a solution and coming up with those solutions, even if it's as simple as where to run a blower line, is Design. One of the cleverest design solutions I ever saw was a very small saddle tank engine (in 16mm IIRC) which made the saddle tank (heavily built and adequately stayed) the Boiler! What would normally have been the boiler barrel was the firebox. BTW I am an architect in real life and that's how a building design starts . . . needs or problems looking for solutions.
 
Hello Harry - when did you sneak in? Welcome anyway.
 
Every so often I see statements like "some of the things <XYZ> used to do aren't acceptable anymore" (where XYZ is some famous ME personage; LBSC, ME, EV, GS, etc..), but no details on what is and isn't best practice anymore. Is there a list somewhere?

Thanks.
 
Welcome to the forum Harry.

I've never made one but I know a boiler is in my future. Always glad to have another teacher around. Thanks now for the future help.
 
Welcome to HMEM Harry. There is a lot of interest in boiler making on HMEM and your input to keep us on the straight and narrow will be welcome. I have missed chatting with you at steamups, but I don't get out much anymore. Just stay home and build toys.
Gail in NM
Gail Graham
 
tel said:
Hello Harry - when did you sneak in? Welcome anyway.
Hello TEL, and Howdy GAIL, you old sod. Where have you been!? I'm glad to know you're still kicking around and likewise I don't get to any meets much any more myself. There's too much too much to do around here these days.

Shred,
I don't know of a "list" per se, over time and much reading we acquire mental and paper files of these things and apply them when the time comes. I've built enough boilers so that I have my own set of basic practices which I use on every boiler but naturally there are variations in how I do it and how others do it. Vive la difference, as long as certain minum standards and practices are observed. The variations I use typically exceed the minumum standards and allow me to do a better job with my skills and equipment.

I'll give you an example of one technological change, or change in accepted practice, from say the heyday of LBSC. Curly very often called for screws and fittings to be screwed directly into the copper sheet and consequently, as the models aged (and probably when they were new) the copper would wear or stretch and leak and after a point could never again be made to seal. Most such boilers I see have been goobed up with thread compound or soft solder in futile attempts to seal the leaks. Nowadays it is almost universally accepted as good practice that all boiler penetrations be bushed. This true of both copper and steel construction. In copper the preferred material both in the UK and the US is phosphor bronze (US/CD510) with "gunmetal" (a red bronze) being near equal in preference in the UK. Copper and other bronzes such as SAE660 bearing bronze can be used for bushings, but not brass. I use a lot of 660 bronze because it's available locally at a walk-in counter. The reason phosphor bronze is a first choice for bushings is it will silver solder like copper but it will hold a thread like steel. It's drawback is it is not as commonly available as say a bearing bronze and it's tough as nails to machine, but I love the stuff.

There are number of changes like this and most of them were made to make boilers safer, more maintenance-free, longer lived, and more efficient. As I said though, opinions vary among experienced boiler builders.
 
Welcome aboard Harry, boilers are a popular subject here so you could be quite busy ;)

CC
 
Welcome GWRdriver Thm: !

I follow some of your posting over on the Chaski Live Steam forum. Glad you found your way over here. Always great to see talented folks offering their experience to help us machining neophytes !!

My goal is to work up to to build a live steam locomotive. Starting out small and working my way up to larger engines. Got an Allen mogul in mind since I know Gene Allen !

Mike
 
Been putting off boiler building since I don't know beans about it. So welcome, good to have you join us.
 
Thanks for all the welcomes. This appears to be a very busy place.
 
Harry,

Welcome to our forum.
icon_welcome.gif


Best Regards
Bob
 
I definitly do not wish to upset our friend GWRdriver but if standards are required then the Aussies have come up with 3 sets of standards.

They are the products of the "Australian Miniature Boiler Safety Committee" AMBSC. There are 3 parts.

1. Copper Boilers. Covering up to total enclosed volume of 50 litres. These cover most boilers required for passenger carrying miniature railway use. Typical of Model Engineering Club usage.

2. Steel boilers. Same as for copper except made from steel. Covers locomotive type boilers and vertical fire tube boilers for steam boat or stationary use.

3. Sub-Miniature Boilers. something of an afterthought to cover the "toy" sized boiler and particularly the live steam garden railway people (of which I am one!). The scope is up to 77mm (3") external diameter, volume up to 1 litre and operate at a pressure not greater than 75psi (520kPa). Covers 9 boiler types used in G0 & G1 outdoor railways and 2 water tube boilers for model boats.

The good point of all these standards is that they cover all required details so that they allow plenty of flexability in general design as long as the details are covered.

I have heard some say these standards are a bit tough and over the top but for my money I like that as the boilers built to the standards ensure a level of quality which translates into safety - a state we all should hold up as the most important condition of playing with live steam.

Brian
 
. . . I like that as the boilers built to the standards ensure a level of quality which translates into safety - a state we all should hold up as the most important condition of playing with live steam. - Brian
And in this we completely agree although as always there are more ways than one to bake a cake. One of the things I find problematic is the tendency of some folks to read just one book . . . that is, to take one source or authority, such as LBSC or Kozo, or the AMBSC, as gospel to the virtual exclusion of all others and in doing so throw out valid practices which have served well for many years. Likewise it's occasionally good to throw out outdated practice when better alternatives are developed. It should be noted that the world model boiler safety record after the advent of the AMBSC is no better or worse than it was before the appearance of the AMBSC so those of us who don't strictly adhere to the AMBSC must be doing something right.

A few years ago a few vocal Australians (dizzy from hanging upside down too long?), attempted to push the AMBSC off on the rest of the world and ended up getting told (in other forums long ago and far away) to back off. To their credit this advice was taken and what was accomplished IMHO was to allow everyone a bit of breathing room where the AMBSC code could be considered on its merits (or lack of) without feeling it was being forced down anyone's throat, which some of us were feeling, or being told we were looney if we didn't embrace this code. Many of us are still in consideration mode. It might be of interest to know that a few years ago I was asked by colleagues in Oz to review, comment, and possibly contribute to the embryo sub-miniature boiler portion of the AMBSC hoever I found it to be generally comprehensive and well done and not in need of comment from me.

I definitly do not wish to upset our friend GWRdriver but if standards are required . . . .
IF is the key word here. The UK is obliged (some might say burdened) to follow certain standards of construction and certification for insurance purposes. The AMBSC was likewise originally developed in concert with regulators and insurors to provide a set of mutually agreed upon standards. Please correct me if I am far off the mark on this.
Things are different in the USA and one significant difference is the US live steamer's native independance (or obstinance), the tendency to resist being told what to do, especially with regard to hobby activities. So far as I know all attempts to develop a model boiler code in the US have been shouted down or in some way torpedoed. One reason we are free to indulge ourselves in this way is that the insurors don't much care about boilers, we fly under their radar. Their primary concen is with passenger safety and liability, because that's where the majority of injuries have occurred and where the claims originate. That doesn't make sense to us but that's the way it is. If the insurors were to come down on us and say "OK boys, codify, certify, and test your boilers, or else we won't insure you" then we would very quickly have a code also.

PS - Lest I seem to be short-fused with Brian, and/or the AMBSC (hopefully not), I ought to clarify that my boiler building techniques come mostly from guidance gleaned from The Model Engineer (mag), and its writers, and from local mentors, and then tempered by personal experimentation with those techniques. I also learned that knowing what NOT to do is as important as learning what To do. That's how I learned what I know and so far it has served me well.
 
GWRdriver said:
This appears to be a very busy place.

It is, and it's very friendly too ............ that's what makes it so popular 8)

I've been reading quite a few of your posts and threads Harry and they are very enjoyable, informative and helpful, thank you, please keep up the good work.

CC
 

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