Model Engine Maker

Supporting => Boilers => Topic started by: Zephyrin on May 02, 2017, 08:12:58 AM

Title: An antique steel boiler
Post by: Zephyrin on May 02, 2017, 08:12:58 AM
Here is an antique (model ?)  boiler received as a gift, undoubtedly rather old and rusted, made entirely out of steel, a very crude construction, of which I do not manage to trace the origin… nor the use.
It is large, about 3.3 litre (3.5 quart) and heavily built, almost 10 kg.
A thick steel tube of 160 mm dia, with bottom and top ends flanged and riveted by a line of large rivets, and crossed by 4 small flue tubes grouped in the middle of the end plates, obviously too small for an efficient boiler.
This boiler is simply inserted on a base made of steel too, posed on 4 nice forged feet, with a furnace’s door (broken, but that I have just repaired), with ample place for any kind of burner able to heat all this mass of metal.
Tapped holes in the tube and top end plate are well positioned to receive all necessary equipment for a “sterling” boiler.
What intrigues me, it looks crude and made by an amateur, able to pose large steel rivets (I had to change a rivet on the fire door, really a physical job).
I do not see how the sealing is carried out, apart from the rivets.

It is certainly not the boiler which I was dreaming about, but now I have it, and if recoverable, this piece could be appropriate for a large vertical steam engine I made 10 years ago, witch, up to now run only on air.

Title: Re: An antique steel boiler
Post by: steam guy willy on May 02, 2017, 03:41:51 PM
Interesting item and a nice project  love it .........
Title: Re: An antique steel boiler
Post by: zeeprogrammer on May 02, 2017, 11:11:59 PM
That 'is' interesting.

It's really too bad that it's history is lost.
Title: Re: An antique steel boiler
Post by: derekwarner on May 03, 2017, 05:11:31 AM
Zephyrin....this is a very interesting old boiler...[the design however :old: may not really be all that crude] .........I am pretty sure I understand the method of construction however offer....

Underside View of Boiler with the lower base insert ring & disc to the boiler shell
a. 4 x vertical fire tubes - expanded or flared sealing
b. 4 x vertical boiler stays  - riveted or expanded sealing
c. the lower base insert disc is double riveted with every second rivet blind or countersunk externally to the boiler shell
d. the lower base insert disc ring is double riveted to the boiler shell

e. Supporting base shell confirms 3 of [4?] longer rivets that would support a fire grate
f. the boiler top plate to outer shell construction appears to be the double riveted construction
g. you have identified M8x1 and M10x1 tapping's etc
h. the water tightness integrity from original construction would have been by mechanical metal to metal chalking between the boiler top & bottom plates to the shell

To test the boiler opens Pandora's box

Any engineer engaged to check & certify the boiler would need to
i. ultrasonic determination of the boiler shell wall thickness, together with the 4 x fire tube wall integrity so also the determination of the tube thickness. The boiler top plate & bottom plate thickness would also need to be confirmed
j. from this, boiler hoop strength calculations could be made.....[without material Grade nomination, a derated calculation would be applied] thus to confirm firstly a working pressure, then nominate a test pressure

If the boiler were for your own personal use and not for public exhibition, you could consider the following simple test
k. add a steam safety valve pre set to say 2 Bar to the boiler top plate + a filling port, a calibrated 6 Bar burden type pressure  gauge + a water gauge to the boiler shell

l. fill the boiler to ~~ 75% of the shell volume with water, and gradually apply heat [pancake ceramic burner] to the underside of boiler base ....... [see reference from Paul Gough Reply #9 on: Today at 11:28:00 PM]

l. To perform the hydrostatic test, fill the  boiler to 100% and bleed all air, then gradually apply heat to expand the volume of water.....thus easier to detect any leakage than with a small displacement hand pump which may not be capable of attaining  a pressure increase due to internal leakage

m. having a $20.00 digital pyrometer would be an asset in the constant temperature increase accompanied with the viewing of the pressure gauge

:Director: Stand back & see what happens................

Good luck.......... Derek  ..... :cheers:

NB...the above is only an assessment and not a recommendation in any form of boiler pressure testing procedure. Testing of any pressure vessel must be made in accordance with your Local  State or Government requirements 
Title: Re: An antique steel boiler
Post by: Zephyrin on May 03, 2017, 10:34:34 AM
It's really too bad that it's history is lost.

Zee : I feel exactly the same each time I have an old and rusted tool in hands, simply getting older?

Anyway, I guess that it is not too much to ask to this piece just a few steam up as a retirement !

Derek: Thank you for this detailed answer, you are right on all the points raised!
Indeed, the base plate seems to be riveted to an angle bent in circle, (I cannot do that, with 3mm steel , I’m not strong enough !) and then riveted to the boiler shell. The rivets appear to be hammered by hand  - this fellow was really beefy -   the force required (about 8 mm for the rounded head and 5mm stem) must be absolutely huge, considering the effort I did to replace an hinge and a rivet on the fire door…

As regard the burner, yes a coal grate and an ashes tray are easy to install, and I would like to have a go, but for now, a short run with a butane gas burner would be certainly an easier goal.…

Title: Re: An antique steel boiler
Post by: Zephyrin on May 03, 2017, 11:02:03 AM
I thought I would get this overhaul wrapped in 3-4 days just by turning a few boiler accessories…but it was not so!

I did threaded bushings for the holes, then fill it with water (3.3 litre !) and tested the whole under water pressure, but no pressure at all, huge leaks from inside the brass flue tubes...
picture 1 :
I removed these tubes by drilling through them, with care to avoid that a tube fall inside the boiler !
photo 2
3 of them were cracked lengthwise, almost completely, hence the leaks !
photo 3
I rebored the end plates, and put back 4 larger copper tubes, by expansion, with 2 shop made cone plugs driven by a threaded rod and nuts.
Photo 4
My boiler with its new larger copper tubes on pressure test again, to my surprise, was now waterproof ! During the test 1-2 water drops were visible beyond 9 bar at the junction of the tubes with the boiler end plates, and no leak anywhere else on the boiler, pressure remaining stable at 8 bar (115 psi) for more than 30 min.
Maybe I might caulk these junctions with tin solder…

I realize now that the copper tubes are liable to elongate and dissociate from the bottom plates owing to the differential expansion between copper and steel upon heating; I wonder if these length constraints could be the cause of the longitudinal slits observed on the tubes that I just have removed, and as the same causes produce the same effects, could it happen again...

Anyway, I think it is conclusive enough to resume this overhaul, next step being steam production.

Title: Re: An antique steel boiler
Post by: Steamer5 on May 03, 2017, 01:02:20 PM
Hi Zephyrin,
 Nice boiler!
Well done on the fix, the guy who built it did a great job on his riveting!  On you weeps why not try re-swaging the tubes....gently...rather than soldering?

Cheers Kerrin
Title: Re: An antique steel boiler
Post by: derekwarner on May 03, 2017, 02:05:09 PM
Zephyrin.....well done is interesting to see such progress

1. the failed fire tubes appear to be from the red brass family
2. your replacement fire tubes being from copper is a far better consideration from a metallurgical/mechanical aspect
3. the expansion ratio between diameter to length for copper is greater than red brass
4. the riveting process would have been achieved with each individual rivet being  :Mad: hot or in a plastic state prior to installation and the forming of the head. The resulting cooling also assists in the closure of the mating steel surfaces surrounding the diameter of the shank of each rivet     

Digressing, copper firebox tubes in [5" gauge] model steam engines are silver soldered, and are approved under various boiler codes for use ~~ 100+ PSI working pressures

You may well find a local model steam train club with a boiler inspector will offer constructive comment, however such a person may decline to be involved....... that is without Drawings or specification

Derek  :cheers:
Title: Re: An antique steel boiler
Post by: paul gough on May 03, 2017, 11:28:00 PM
Very glad you did a cold water hydraulic test before applying any heat, a must before applying any heat to an unknown boiler. From my reading on old boilers brass tube splitting was not unusual. From my experience with larger size 'model', (12 inch gauge), loco boilers which are mostly 10 to 16 inch dia. both class one, >100 psi, and class 2 < 100 psi, copper tubes do not pose any great problem if expanded into the tube plates properly, raising steam is done appropriately, i.e. slowly or 'gently' as an old fireman who instructed me over half a century ago used to say, until you have ten psi, then things can be pushed along. If the boiler is used for long periods, multiple hours, and frequently then some simple water treatment might be worth considering. A normal boiler washout/inspection regime should be upheld until you become familiar with sedimentation, scaling and any physical changes. Sorry if I am going over what you and experienced members already know, but I was a little concerned when one poster advised of a 'simple test' using a gas burner and stand back and see what happens, without mentioning the need for a hydraulic test first. We have many readers who may have little knowledge of boilers and advice regarding boiler testing needs to be thoughtfully done. Trust the little 'antique' gives you plenty of steam for your engines. Regards Paul Gough.
Title: Re: An antique steel boiler
Post by: derekwarner on May 03, 2017, 11:41:11 PM
Thank you are totally correct in the application of a hydrostatic test prior to a steam test

With such a large volume ~~ 3+ litre, most scale hand pump displacement would not compensate for any internal or external leakage

I will go back and revise my text to nominate filling the boiler to 100% and bleed all air, then gradually apply heat to expand the volume of water.....thus easier to detect any leakage [my choice of 'see what happens' could be mis construed as inappropriate]

Title: Re: An antique steel boiler
Post by: paul gough on May 04, 2017, 01:17:55 AM
Derek, Glad you understood where I was coming from.

Zephyrin, Looking again at your pictures of the boiler, it reminded me of a very similar design and size, might have been 8 inch Dia., I came across for sale here in North Queensland some years ago. It was from the 1930s and was said to have come from a butchers shop, (boucherie). I cannot remember what it was used for, but this may have been a time when there was no electricity available, not uncommon in remoter rural areas here at this time. The chimney and firebox on yours appears to be 'older looking' and ornate in its design but I wondered if it might have been something similar and not a 'model'. If the boiler plates etc. seem very thick for their size and there is any possibility this boiler might date from before 1900 then there is a very slight chance it is a wrought iron one, which would make it really 'antique'. Any thoughts about its age and use??? Regards Paul Gough. P.S. The tiny tubes might indicate it had a gas burner.
Title: Re: An antique steel boiler
Post by: Jasonb on May 04, 2017, 08:00:04 AM
This boiler looks to have such a small heating area - only 4 small firetubes and the bottom plate that given its unknown state I would be tempted to cut out the bottom plate and fit a new copper boiler inside the shell with far more tubes. Staop teh new boiler say 25mm short of the existing top plate and then the heat from teh new tubes can go up the old chimney.

This will give a boiler that is going to produce enough steam to run that engine, easy to coal fire and be safe yet still look like the old antique

Title: Re: An antique steel boiler
Post by: Zephyrin on May 04, 2017, 09:07:16 AM
Thanks for all these inputs...
Jason :
I fully agree that the flue tubes (even the new ones) and heating area are too small for an efficient boiler, and if I fail to run my engine, doing a new copper boiler inside is a very good suggestion to save the day. However, removing cleanly that bottom end plate is not what I call an easy job...
Paul :
This is exactly what I'm asking. I have no info on the origin and the use of this boiler; and I'm not sure if it is a "model" , which would have been much lighter, as compared to genuine ancient model boiler made by Radiguet for example.
I have got it 3 weeks ago for my 70th birthday, and I love it.

It looks like worked by a blacksmith in its dark shop, the coal forge glowing red with the blower, the young companion with a two handed hammer...

I did more than 20 boiler, from tiny to small, 0.1 to 0.5 litre, "conventional" ones, with silver soldered copper tubes, mostly for gauge 1 & 0 locos ; therefore swaging copper tubes in a 10 kg piece of iron is a great change.
I did a heating test with a small camping butane burner and 0.5 l of water in the boiler; it take about 30 min to get a decent jet of steam...
but as far as I remind my camping days, this delay to get a boiling soup is not unexpected.
Title: Re: An antique steel boiler
Post by: paul gough on May 04, 2017, 09:35:10 AM
Francois-Marie, Please be sure your little boiler is of no historical interest or value  before doing any major changes to it. It had brass tubes, which indicates might be very old. If so, even the old brass tubes would be worth keeping. A few photos and some enquiries at an appropriate museum might provide some answers.

I am very sorry I did not take a photo of the 'butchers boiler' so you could compare. I think you are correct about a blacksmith, the work on the 'firebox' has the appearance of a blacksmiths work, I love the feet on it. To me the fact that it has very small brass tubes, is all riveted with thick material and appears to be very old provides enough reason to be careful. I am even wondering if this boiler was for steam, maybe it was a small hot water boiler that could deliver the water under low pressure, I am guessing, but there were such things to sit on top of solid fuel stoves.

Does the boiler have fittings/bushes for; a water level sight glass, safety valve, etc??? Regards Paul Gough. P.S. The boiler barrel looks to have a different patina/colour than the chimney or the fire box, do you think this might be the case, it might be a newer section.
Title: Re: An antique steel boiler
Post by: Zephyrin on May 04, 2017, 10:13:07 AM
Does the boiler have fittings/bushes for; a water level sight glass, safety valve, etc??? Regards Paul Gough. P.S. The boiler barrel looks to have a different patina/colour than the chimney or the fire box, do you think this might be the case, it might be a newer section.
Yes Paul, the boiler have many tapped holes for accessories, water gauge, clack valve, pressure valve etc, all exactly were I would drill them, I have nothing to plug or redrill, hence my conclusion that it is a steam generator pretty good for my engine and not kind of expresso machine !

as regard the patina, I'm pretty sure that the outer part of the barrel has been fully sandblasted. It was given to me by my brother, which does have a sandblaster, and people which have one, they sandblast everything around.
Title: Re: An antique steel boiler
Post by: Jasonb on May 04, 2017, 10:21:37 AM
I can't see it being used ontop of a stove, it has a firebox for one and there would be very little heat transfer from the stove with the bottom plate set up into the barrel, you would want a flush bottom to make contact with the stove.

Are you just flaring the ends of your copper tubes? They would be better off being expanded but you ideally need a good finish eg reamed hole and the plate needs to be of adequate thickness for the tube to make a good seal. How thick is the barrel and what thickness are the top and bottom plates?

Title: Re: An antique steel boiler
Post by: Zephyrin on May 04, 2017, 10:49:37 AM
The camping burner is small enough to enter into the firebox, similar to a saucepan ! 
No, the tubes are not just flared, I reamed the redrilled holes, I did different coned plugs, first with a very small cone to press fully the annealed tubes in the hole, a second plug, with a more steep cone, (pretty hard to remove from the tubes !) the flaring of the ends was done to finish.
the thickness of the plate is about 3 to 4 mm, the same for the barrel tube, but at the top plate junction, thickness appears twice that.
Title: Re: An antique steel boiler
Post by: paul gough on May 04, 2017, 12:18:19 PM
It seems from what you have said it is a steam boiler.  If this little boiler is not a model and clearly it was not meant to create a lot of steam at a high pressure, what sort of uses could it be put to??? Apart from something similar to the one said to be used by a butcher, the only practical use that I can think of would be for a small scale apiarist or beekeeper/farmer to use with a steam heated de-capping knife/iron prior to putting the frames in a separator for honey extraction, and  perhaps some other modest steam heated appliance. All speculation of course, but maybe it will give you an idea. Paul.
Title: Re: An antique steel boiler
Post by: Zephyrin on May 05, 2017, 08:54:53 AM

As boiler inspector was not looking, I did a test with my engine, I was too anxious to know the results...
I put a piece of tubing between boiler and engine and have a go.

My engine is pretty large, double acting, with 40 mm bore and 70 mm stroke, i.e. 176 cm3, with 70% cut-off, it uses 123 cm3 of steam per revolution, which at 2 bar represents 0.24 g of water;  at a minimum speed, say 120-150 rpm, this is more than 0.5 g of water vaporized per second.

After waiting ages to get steam, plus some heating of the engine with a soldering torch to reduce condensation, then the engine eventually started to run, slowly of course and continue to run for half an hour...
It’s a pity that the ball regulator slipped and was going wrong, keeping the valve closed, I had to keep it open by hand !

Clearly, the heating was too short, pressure hardly reached 1 bar on the gauge, I have to replace butane with the butane/propane mix, and a good thermal insulation is necessary.

This first run is a little pushy but for a first try...I’m happy !

For the next test, I have to make a burner and the boiler fittings, much larger than those I use on my little locos; I’m searching for good looking models to copy for a water gauge and a safety valve. 

The weight of the engine is about 15 kg, and as the boiler reaches 10kg, I need a small trolley if I want to keep them assembled together, that was not planed at first, wow!
Title: Re: An antique steel boiler
Post by: paul gough on May 05, 2017, 10:00:37 AM
Here is small boiler that might be contemporary with yours, Paul.
Title: Re: An antique steel boiler
Post by: Zephyrin on May 05, 2017, 10:30:00 AM
Wow! pretty good finding, Paul, it looks very similar !
I don't know its use, I see a leather belt around and straps too, some sort of portable device ?
I agree that applications of steam must be numerous in the rural life at large. A boiler to melt beewax ; looking at it on the internet, you're getting closer...
Title: Re: An antique steel boiler
Post by: paul gough on May 05, 2017, 11:21:08 AM
I cannot help with any details about the little boiler, the straps appear to be associated with it, maybe a tiny portable, but the whistle makes it seem like a model. Maybe it was fitted later, I have no idea. The gauge glass arrangement looks attractive to me. Below is a youtube clip demonstrating a steam uncapping knife, a more modern one than I used at my friends farm helping him extract honey. Slow hard work when you have to turn the handle of the extractor as well as do all the uncapping manually. The hunt for historical information can be very rewarding. Second link is to Ebay where there is a model which has boiler fittings which might appeal to you. Regards,  paul.


Title: Re: An antique steel boiler
Post by: Zephyrin on May 05, 2017, 02:18:37 PM
Well spotted  again, Paul ! (
 this a fine steam engine by Radiguet, the most famous french builder of model steam engine, toys, scientific apparatus etc in the 1900s…1889 for this one, (although this commemorative date does not refer necessarily to the date of fabrication)
The same model was made by Radiguet in several size (and prize !).
I did my engine more than 10 years ago from an incomplete but so appealing set of large iron castings that I have found in a flea market, which were most likely castings (or copies castings) for the larger size of this Radiguet engine !
I have some pictures of the build in my google albums
I hope I could transform my boiler in such a so elegant piece of collection.
Title: Re: An antique steel boiler
Post by: paul gough on May 05, 2017, 02:57:17 PM
Good luck with your restoration and please post some photos when you get it finished. Regards, Paul.
Title: Re: An antique steel boiler
Post by: Zephyrin on June 15, 2017, 11:41:13 AM

I turned all the necessary accessories for the boiler ...
 Basically, they are the same as usual, but 2 to 3 times larger ! I have never done boiler that large in fact !
My stocks of brass and bronze reduced at an alarming rate, I had to resort to brazed assemblies by recycling old plumbing fittings for largest parts. A scrap metal recycler lies in every model engine builder...

I added an insulating layer with a 6mm thick sheet of cork, and covered with a recycled tin plate. I have found that lagging is essential with my small loco boilers, and must be required with this poorly designed boiler.
The water gauge has a 8mm glass tube.
A large blow-down tap is also fitted, as I plan to dry the boiler completely between steaming again to avoid rusting.

There is also a safety valve with an arm and weight, of my own, with 2 positions for the weight calculated to blow at 2.5 and 3.2 bar…I could evaluate soon my maths level…

I turned a large bronze steam valve, with my favourite method with form tool, always a delight for me.

( (

As my engine already has a feed pump, a check valve was obviously fitted, and should be required owing to the large steam intake, 125 cm3 of steam for 1 rotation of the crankshaft, i.e. 25 litre/min at 200 rpm, or about 40 cm3 of water/ minute at 2 bar.

Title: Re: An antique steel boiler
Post by: Zephyrin on June 15, 2017, 11:53:15 AM

Unfortunately, but not unexpected, the power of the burner is limited by the small section of the fire tubes ; I installed a camping butane burner in the fireplace, rated 3000W, much stronger than the smaller type I used for the trial test.
 Of course, he does not want to work at maximum power, the hot gases blow back and the burner goes off, I had to lower the power up to get a stable flame. Anyway, the burner still heats enough, and produces steam continuously and maintains the pressure. Once the boiler is hot, it is much better, I can increase the heating a little, and the blower seems very efficient to improve hot gases release.

I did a first heating with all the accessories, and I have of course leaks everywhere, especially at the filler cap; because of its large diameter, a part of it is in the curvature of the boiler‘s top, the seal bears badly; I have to fix that, otherwise the over tightening of the cap will rapidly screw up the thread.

( (

The boiler is near from a final assembly with the engine, and as a water feed pump is already present on my engine, I have to make a water tank and a bypass valve, and finally joining together boiler and engine with all the piping for steam and water.

I do not see where to hide this ugly tank of butane...

Title: Re: An antique steel boiler
Post by: Zephyrin on July 01, 2017, 11:21:59 AM
The renovation of my old steel boiler is now complete, including a whistle !
With the butane burner, the steam production allows the operation of my large vertical engine at a good pace, the engine runs easily from 60 rpm up to almost 300 rpm, with the pressure gauge between 0.75-1.5 bar.
The burner requires a blower to improve draught through the narrow smoke tubes, and as soon as the engine is running, the exhaust replaces it. At the lower speeds however, a lot of condensation occurs in the exhaust pipe, hence the gurgling noise.
I have to put some insulating stuff around the tubes. 
The cylinder capacity of the engine is large, as is the water consumption, and the water pump capacity is large enough to restore the water level in a few strokes, the increased level being visible shortly through the water gauge, but also cools the boiler and slows the engine ! Clearly the pump is overrated. The reduction of the pump capacity by 5 would allow a steady water level, I guess.
With the engine supplied with steam, the safety valve never blows, the pressure of 2.5 bar is reached only if the steam valve is closed.
The main problem is the weight of this steam plan, about 25 kg, not that easy to put away somewhere !
And what to drive with this engine, this hobby never stops...

Title: Re: An antique steel boiler
Post by: Ye-Ole Steam Dude on July 01, 2017, 12:47:21 PM
Great video, thanks for sharing.

Two really beautiful pieces of machinery, well done.
Title: Re: An antique steel boiler
Post by: paul gough on July 10, 2017, 11:40:39 PM
Hi Zephyrin, You have done a very good job with the restoration and matching the boiler with an engine that runs well even despite its limited capacity. If you think their is enough power to run a water pump this might provide something of interest. Perhaps something with a mechanical motion might add even more visual pleasure to your plant. As an example a double ended ram pump pushing water up to a header tank might be do-able. Mechanical pumps such as Weirs and Worthington types are always fascinating to watch, especially the latter busily doing their job. Have you come to any conclusion about the boilers original use. Regards Paul Gough
Title: Re: An antique steel boiler
Post by: gary.a.ayres on May 11, 2020, 11:58:49 PM
A really interesting thread on this beautiful boiler.

Great restoration, and that vertical engine you built looks fantastic too.

Very nice!