# Coal-fired C-25 boiler complete!



## lenicheck (Jan 8, 2008)

Well, guys, I've been cranking on my coal-fired C-25 boiler for quite a while and it's finally done and tested to 150psi. Really made my day today. Attached are some progress pics of the engine and components so far. 

Johnson Bar:









Full Stephenson's with axle pump:










Front truck. As on the frame, the springs were 3D printed in stainless.










Front pilot area. Some of this design was a best guess. I used an old C-16 Accucraft pilot I had on hand. The cap at the front of the steam intake/exhaust manifold is the lubricator line in.










Coal grate with retainer pin. The grate and ashpan pull out as one unit for cleaning.










The boiler pieces. Some of these have not been cleaned up. This is the third iteration for the throat plate (the semi-circular piece directly below the boiler tube). The larger tube allows for the superheater pipe.










Boiler testing - 15 min at 150psi. Did have one small leak in the mud ring I had the fix. 










Boiler showing front tube plate. Ugly looking silver solder at the front that just wouldn't clean up in my pickling soln. The two extensions at 3&9 oclock are for holding the smokebox on. The other, threaded extension is the blower.










The firebox end showing the dry backhead. The stay pattern was designed using a program Steve Shyvers found which was originated by the Chesapeake and Allegheny Live Steamers. ( http://calslivesteam.org/calculations/Calculations.htm.)










Firebox and mud ring. The firebox is about 2" X 2.5". should make for a good fire. 










More updates later. Thanks for viewing.


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## Greg Elmassian (Jan 3, 2008)

WOW! 

Looks great. 

I don't know much about 3d printing of stainless... is there a process that puts down bits of stainless, or is it etched away, etc? 

Greg


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## placitassteam (Jan 2, 2008)

Rob, That is looking great. I hope to see it run at my place or Don's when you get it done. Sorry you can't make it here in October.


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## xo18thfa (Jan 2, 2008)

Rob: Truly beautiful work. That boiler will steam raw crazy.


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## Slipped Eccentric (Jan 2, 2008)

Very nice! Scotch yoke on the axle pump?


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## seadawg (Jan 2, 2008)

Looks great Rob! Real tight between the frames!


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## Dwight Ennis (Jan 2, 2008)

Looks fabulous Rob!!





















How many hours per day do you work on this on average if I can ask?


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## HMeinhold (Jan 2, 2008)

Rob,
your boiler turned out really well. Will you bring it to the steam-up Saturday? By the way, is it possible the silver solder at the front tube sheet was accidently "overcooked"? 
Regards


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## Steve Shyvers (Jan 2, 2008)

Very nice, Rob. I like the way you've designed the grate and ash pan. 

Steve


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## Steve Shyvers (Jan 2, 2008)

Henner, 

Overcooked? I think I know what you mean although I have not heard that term applied to it. I've seen how repeated heatings can change the surface appearance of silver solder that was applied previously. Do you know what has changed in the silver solder in terms of chemistry, strength, hardness, etc.? 

Steve


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## lenicheck (Jan 8, 2008)

Henner, don't know if I overcooked the solder or not. Seems to hold pressure just fine. I did notice that the solder on other parts of the boiler changed color in a similar fashion unless I fluxed and heated it again.

Yup, scotch yoke design mostly thanks to Torry's encouragement.

Dwight, I've spent less time on this engine than I'd like but I suppose I get to spend 2-3 hrs a day during the week on it. The boiler took about 6 months or so.


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## ChaoticRambo (Nov 20, 2010)

Very cool.

What is the operating pressure going to be? I am guessing 100 psi since you tested to 150?

Was this built from an Accucraft C-25, or is this project all scratch built? - Either way it looks amazing.


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## David BaileyK27 (Jan 2, 2008)

I guess that 60PSI would be sufficient, this is the pressure I run my scratch built C25 at which has a similar coal fired boiler to Robs and has plenty of power, it has 3/4" dia cylinders which makes it very docile to run, 
Some of you may remember seeing it at Diamondhead several years ago. 
David Bailey DJB Model Engineering.


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## seadawg (Jan 2, 2008)

We would like to see it again David!


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## David BaileyK27 (Jan 2, 2008)

Dave. it is unlikly that we will be coming to Diamondhead again but if you would like to contact me off group I will send you some pictures, I am unable to post pictures here. 
David


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## seadawg (Jan 2, 2008)

Posted By David BaileyK27 on 21 Sep 2012 02:10 PM 
Dave. it is unlikly that we will be coming to Diamondhead again but if you would like to contact me off group I will send you some pictures, I am unable to post pictures here. 
David 

Sorry to hear that, I was really intimating that it would be good to see _YOU_ poolside and have a chance to shoot the breeze.


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## lenicheck (Jan 8, 2008)

David, 

Great to hear from you and I agree with Dave Orwig. It would be good to chat over the pool at DH. 

I'm planning my boiler to pop at 70 psi, hence the 150 test. Only hope the other parameters are right to make things go...


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## Chris Scott (Jan 2, 2008)

Rob:
Should the urge attack you convert from a coal burner to a ceramic radiant gas burner. Aster's Big Boys came able to convert to burn coal or use a ceramic gas burner (both Big Boy editions). You could probably copy Aster's burner. 
There is also documentation on the G1MRA web site for ceramic burner design. The G1MRA Dee project locomotive is convertible between coal and gas. I have a couple of blocks of ceramic burner material if you need a piece. Same ceramic used in available standard ceramic burners - drilled hole matrix and convoluted surface. Kevin O'Connor's Big Boy is gas fired; someone experienced with Aster's. Chances are good he improved on Aster's approach.


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## Taperpin (Jan 6, 2008)

Chris, 
The Aster Big boy had a triple slotted burner .3 of the common type tubes arranged in "Delta" form and fed by one common gas jet, as it had to be insertable through the firedoor, worke fine but cost a fortune to refill! 

and Rob the boiler looks great.... 

Gordon.


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## Two Blocked (Feb 22, 2008)

Rob, very nice work. All the photos have a toastie cast to them; especially the boiler test photo. I suggest securing an auto wet cell hydrometer from the NAPA store and test the specific gravity of your acid pickle tank. Sparex, the dry powder-mixed-with-water pickling agent when freshly mixed according to instructions, will yield a specific gravity of 1.25 [1250 on the green line]. If your readings are 1125, or less, you might consider refreshing the mix and re-pickling to remove more discoloration. A better surface finish can also be had by purchasing the copper bottomed pot cleaner, KleenKing [kleenking.com], and making up a slush to apply, work by brush [tooth type is good], and rinse with a hose sprayer. Some would say "why bother, it's all going to be covered up anyway .....? A craftsman's dilemma.
Chris, all the Aster Big Boys have full-up wet walled locomotive type boilers, and were designed for coal or butane gas fuels. As Gordon has written, the only access to the combustion chamber is the round hole in the backhead which is hard pressed to even accept the three piece folding stainless heat reflector that shields the trailing truck from the heat of combustion generated by the butane burner. There is no way that a potent ceramic burner could be inserted through this access. Gordon is further right in so far as the stock Aster burner is a three element poker burner fed by one, single, gas jet fed manifold. You are right that the burner in my locomotive has only two, but radiant type, pokers. Photos of it in operation exist at southernsteamtrains.com under Notes From Unit Shop. The third position in my burner assembly is occupied by a modified "Charm-Glo" gas barbecue Piezo electric grill lighter that I use to light the burner. 
As Gordon indicated the tender mounted gas fuel tank will hold a full big can of either Primus or Gaz with room to spare. I splice in a container of propane for start up fuel, and then switch to reenforced butane for the run. I have learned to only fill the fuel tank half way. There is now a try-cock installed in the tank to "tell me when". The two radiant poker burners allow for an hour run at 45 psig with 25 MDC box cars in tow as well as the dynamic load car. A lot of work to run, but it is worth it every now and again.


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## bille1906 (May 2, 2009)

Rob 
This is becoming an amazing masterpiece


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