Boiler Build

[potty]

Hi

I don't post very often on this forum my interest is mainly Loco Engines and Stationary Engines but I do like to dip in from time to time.

Any way I've just started a thread on another forum on building the boiler for my 3 1/2" loco. The ? is would this be of any interest to this site as many of the techniques I'll be using will apply to any boiler build, if so I can run the thread her as well.

Her's a taster :--------------

Hi Chaps

I've been putting this off long enough.

But first a warning:- boilers are pressure vessel and are dangerous they are not to be taken lightly, if they fail they can cause serious injury, so due care needs to be taken when you build one. Make sure you understand the boiler regulations that apply to your part of the world, and if you have no experience of boiler building, find someone who is that can guide and mentor you.

I did a lot of research on boiler building, to some extent this was a mistake as I found a lot of contradiction in design and methods, to such an extent that I was seriously looking into buying a commercially made boiler, but this would have cost up to £1500, but I began to realise that methods and thinking have changes over the years and talking to club members and the clubs boiler inspector cleared a lot of the uncertainty up, and with encouragement I decided to have a go at building my own.

To help you Guys to understand some of the term used in the UK I've done a Crap-O-Cad of the type of boiler I will be making.



By way of explanation of some of the terms:-

Stays:- addition support given to flat services

Supper Heater Tubes:- these are large tubes through which pipe work runs that takes "wet steam" collected in the steam dome back through fire box to give it an extra dose of heat.

Throat Plate:- front part of the outer fire box

Foundation Ring:- This fills the space between the outer and inner fire box

Front and Fire box Tube plate:- These are the plates that the Flue and Superheater tubes fit too.

I think the rest of the bits are self explanatory.

I bought a boiler kit for my Loco from Reeves it cost £290.

This is the kit of parts.



Everyone I've spoken to has given me the same bit of advise:- the key to good boiler making is in the preparation, so over the next week or two I'm going to spend some preparing for the build.


Cheers

Stew

[derekwarner_decoy]

Hi PD's ...& thanks ...''potty stew''........there are many Members on PD's with  the love of steam

So welcome on behalf of the group ......we hope to see your boiler build progress ....regards    ....Derek

[granath]

looks neat! looking forward to the build!

some tips that i learned during my build (you maybe already know this but if you don't it will help)


1. get a pickle bath to clean of the parts from oxidation, dirt etc. before you start soldering.

2. practice on silver soldering if you haven't done that before it helps getting things right when it's the real deal, and use some good flux!

and one last thing. to solder this, specially the big parts you are going to need some big heat, and i would recommend that you do some kind of fireplace so you can keep some of the heat in, so it just doesent goes out in the air, it helps a lot! it's amazing how fast the heat disappears from the boiler etc.

well good luck now and keep us posted 

// Victor

[potty]

Well I take that as a yes so:----

OK Made a start not to exciting but every journey begins and ends with a step.

You may think I'm sad but I like to plan out jobs as best I can before I start, I use to make my living designing building and testing items that could be a bit hazardous, if you didn't get your preparation right:- I just can't get out of the habit.

So after much reading and talking to people and listening to advice, I made out a list of items I thought I may need I may end up not using everything but its better to be prepared than wanting. I started my To Do List I'll add to this as thing progress, and as putting a boiler together is complicated and the order of assembly is important:- I listed the order I would assemble the boiler, I may combine some of the operations or even change things round a bit as they go but the shear act of making the list helps make things clearer in your mind:- its all part of the learning curve.

Her's the lists



The first job I thought I would tackle was to make some clamps I want to leave them outside to go rusty so that the solder wont stick to them to easy so the sooner I get them made the better.

A rummage through the scrap box turned these bits of material up.



I burn the paint off the long bars and just squared the ends and sides up in the mill and drilled and tapped them as for toolmakers clamps, they will get a bit of heat so nothing too posh, as long as they will do the job.

The shorter bars again were squared up and a slot milled across and the end drilled and tapped M5, I rounded the jaws off in two of these so that I could grip the rim of the tube without the sharp edges damaging the soft copper.



I was going to make a pair of tongs but them I remembered these.



I bought them at a car boot sale many years ago, don't know why I just thought they would be handy one day, well their day has arrived 

Cheers

Stew

[potty]

Thanks for you comments and advice guys.

Bit more progress I checked the kit of part out and to be honest the flanging is very rough, they look like a Gorilla with a sledge hammer went to work on them. The fire box tube plate should fit in the boiler tube:- No way its about 3mm big



So decided to make a set of former plates and do the job myself, for one off use you can make formers from hardwood or MDF, but the last time I used hard wood I ended up with an allergic rash that took a month to clear up, so nothing for is I'll just have to use ally jig plate a lot more hard work, but one thing old Stewpot is not afraid of is hard work, so after 1 1/2 hr a sore arm, and a bucket of sweat, I got them rough cut out of the plate.



The smoke box tube plate former is round so, the rough cut plate was set up for friction turning.





Before taking an hammer to the copper I annealed it by taking it to a red heat and quenching it in water, this gave me a good feal for the size of burner I'll have to use when I come to solder I ended up using my next to largest burner.



The build guide recommends allowing 3/64 for the plate thinning under the hammer but I gradually reduced the dia of the former trying the tube plate in the tube taking a bit more of the former bashing the plate and tryinng it in the tube until I got a nice push fit.





Next job the fire box former, this is a job for the mill.

I squared the plate up then dolloped some blue on the plate then I used a centre and the DRO feature on the mill and a set of compasses to mark out the shape of the former and and hole positions I then centre popped all round the line.



Back on the mill to mill the shape out you could use the RT for the Radiuses but that level of accuracy is not required I used a trusty old file to bring the shape to the scribed line.



Her's the former and the tidied up fire box plates.



Cheers

Stew

[potty]

Thing have been a little slow, bin on Gardening Duties and looking after our grand son.

Any way made some progress with a backward step thrown in, more about this later.

Made the former for the backhead plate you this former for the throat plate as well. First square it up so that you've got four good edges on each face, then blue it up and mark it out on the mill.



Then centre pop the line to give you something to work too.



Then mill out the shape I used the rotory table this time, it just fitted the clamping is not too elligant, but hay:- its effective.



Then it was just a matter of tidying up the plates on the former her they are all done with the formers.



Now to drill the tube plates now I know that "drilling soft copper can be tricky",  I've seen lots of pics where guys have mounted tubes plates onto lathe face plates so that the holes can be bored because "drilling soft copper can be tricky" but for some reason I decided to do the drilling on my pillar drill, its not a bad pillar drill but its not as good as my mill for drilling, I clamped the smoke box tube plate onto a plank of wood and drilled the first 3/8" hole all was well, now I know that "drilling soft copper can me tricky", second ran out nearly into the first hole that I drilled, I stopped and tried rectifying it by drilling from the other side but this only made things worse:- strike one tube plate



OK it's a scrapper:- so decided to drill the rest of the holes any way to perfect the best method.

Over too the mill:- this is the set up, the plate was position over a slot for the drill to run into and clamping onto a chunk of wood in the middle, so the flange wouldn't be damaged.



That worked like a dream why didn't I do that to begin with

OK have a go with the 3/4" supper heater holes now I know that "drilling soft copper can me tricky", so similar set up, but this time I sat the plate on some parallels flat side on, as the 3/4" was to wide to fit between a slot,:-a 3/8" pilot drill then straight in with the 3/4" now I know that "drilling soft copper can me tricky", that one wandered off centre as well I should have used another pilot drill.

OK second 3/4" hole this time 3/8" followed by 1/2" followed by 3/4" perfect

This is the scrap plate, the 3/4" hole on the left is the one that run out. you can work out for your selves which 3/8" hole went wrong.




Guess what I'll be buying at the Harrogate show, still I've got the formers now.

Stew

Who knows that "drilling soft copper can me tricky"   

 

[potty]

Picked up a nice bit of 2.5mm thick copper the drawing spec is for 13g 2.33mm so its on the safe side, while I was their they cut me a 2" lump of 15/8 phos bronze for the steam dome bush, and I also picked up a length of 1/8 phos bronze to make some closing screws, and a rod of Easy Flo No1 silver solder this has a slightly higher  melting point than Easy Flo No2 that I'm going to use on the bulk of the boiler, but their are a couple of places that I want to use this higher melting point solder, as the joint will be subject to quite bit of high temperatures when I'm soldering additional joints close by.

Work on the new fire box tube plate first job mark out a circle 3 7/8 dia (3 3/8 + 2 * 1/4) the 1/4 is so that the flange can be formed.



Then mark a 3 3/8 dia circle so the former can be centred, then anneal the plate, clamp the disc in the vice with the former and start to fold the flanges over with hammer blows, the copper starts to work harden quite quickly you can feel the material stiffen under the hammer don't try and force it or the copper will split, anneal the plate again.

This is it after the second anneal.



In total I annealed it 7 times before the flange had formed over onto the former.

This is it complete after an hour in the pickle bath.



Well that me back where I started before I try drilling the plate again I'm going to have a bit of an experiment and make some kit that should make the job easyer.

This is going to be a bit  : I want to grind a drill up specifically for sheet metal whilst searching my drill stash for a spare 3/8 and 3/4 drills I came across this sorry site:-



I must have picked it up out of the scrap where I use to work.

So I decided to give it some TLC, my Dad taught me how to grind drills up by hand when I was an apprentice many years ago, and like riding a bike its just something I can do, if you asked me to explain it I couldn't, I could show you but explain it no.

Any way this is the result.





And the proof of the pudding.



Still got the touch 

Stew

[potty]

Quick up date.

John Bogstandard has kindly given me a loan of some imperial step drills:- Thanks John

But I found a problem in using them three of the holes are right up against the flange and the drill will catch it.



So I ground a 3/8 drill up as suggested by Rob  :thumbup: but it cut too 0.020" over size but I found a 23/64 drill among my stash, most of these drill I inherited from my Dad and its a weard and wonderful collection, but don't knock it you can't beat weard .  :nrocks: . So I ground that up and it gave a hole that cleaned up nicely with a 3/8 hand reamer.



Hand a practice with the scrap tube plate, I used a drop of milk as a cutting fluid as suggested by John:- Semi skimmed worked ok

And this is the result.



The bit of sheet is 0.5 mm thick

Top Job

I then drilled 3mm pilot holes in the former using the mill DRO this is the set up.



And made a stubby centre pop out of a bit of 3mm silver steel (drill rod)

And marked the position of the holes in the new boiler tube.





I decided not to drill the tubes just yet as I wont to ask the boiler inspector a couple of questions, I'm a bit concerned with the closeness of some of the tubes to the flange, the drill will just kiss the flange, and I was wondering if a should slightly reposition these holes.

So I'll get on with something else.

Stew

[derekwarner_decoy]

Stew......you couldn't ask for a better mentor than Mr Moore.......he likes his you know .....Derek

[potty]

Hi Derek

I'm lucky to live a five minute walk away from John, and we regularly have a chin wag and coffee.
He keeps me going in the right direction.

Stew

[derekwarner_decoy]

OK Stew......the next time you are talking...could you please inform Mr Moore that I have a 1.025 kg package of dried up beef bones awaiting shipment from OZ to CREWE Engineering for Bandit

I know that bogs will get a laugh from that.....

mmmmm...... from memory he has one can of beer in the fridge from 2002 & he calls it MUCK.....

I do hope that Maralyn is OK...........Derek

[potty]

Derek

Mal is doing fine.

Stew

[potty]

At the club night on Tuesday I took my scrap tube plate along more to get the Chaps talking and it really paid off, some of the old guys are have lots of experience building boilers, along with offers of help if I got stuck I got lots of advice and tips to get the job going.

Any way on with the tube plates:-

I clamped a chunk of wood to the mill table and drilled a hole though it to clear the drill and another for a clamp bolt.

This is the set up.



To drill the holes I started them with a centre drill then for the 3/8 a 8mm cone drill and then a letter U drill the guys at the club recommend not reaming to size but to leave it slightly under size and turn a small step on the boiler tube, this way it will have something to sit against and not fall through when you start to solder.

I used the cone drill for the 3/4 as this was giving a hole that was under size on the tube again I'll take a fine skim off the tube.

Here they are finished.



Next job skim the boiler tube square and too length.

So that the chuck won't damage the tube I turned up a wood plug a nice tight fit in the tube.





With one plug in the chuck end I couldn't get the tube running true at the steady end as the tube was oval so I turned a second plug up for that end as well this pulled the ovality out of the tube.

This is the set up






Cheers

Stew

[potty]

Things have slowed down a bit on the boiler build I've got a paying job that will take up some of my time for the next couple of week.

Got a bit done drilled the holes in the Backhead sorry no pics and made a start on the boiler tube.

Marking it out used the mill table as a flat face.



In order to hold the tube steady for cutting I used this clamp I made it a few years back for another job:- can't remember what  :scratch:
Just two pieces of wood with a coach bolt.



This is it in use



I used a junior hacksaw to do the business, this one has a sentimental attachment for me my father made it many years ago, I didn't want to use a 12" saw as the tooth space would be too wide for the tube and tend to rip also I wanted to take it steady so I got a nice clean straight cut. As the saw was cutting at an angle I didn't take it past the line I left a bit of metal holding the tube together whilst I did the next cut.

This is the next cut, the tool makers clamp is to to stop the cut ends from vibrating and making a farting noise.



The with a junior blade held in a bit of brass chim complete the cuts square.



This is the cut tube.



The cut will be bent out to form the wings of the firebox, I tried to bend them out as cut but the copper is quite hard so I'll anneal it as I didn't want to force it. As the annealed tube will need pickling I,m at a bit of a stop until I get my pickle bathe made.

I've collected one a two things together for the boiler build.



The black box is a case from an industrial battery fork lift truck or something like that, and will be part of the pickle bath, the bits of ally behind it will form part of my brazing hearth. At the Harrogate show I picked up some of these blankets, for the hearth.



I also have a collection of fire bricks.



Getting there slowly

Stew

[derekwarner_decoy]

Hi PD's.......&  keep the pics comming Stew......... ...many PD members love steam  .. ....especially if you have our  "  Bogs " on your side but..... .....Derek