Vertical Boiler for my Moteur Oscillant

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cfellows

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Today I started whacking away on one of the pieces of copper tubing Crab sent me. I cut 3.5" off one tube to flatten out for the end caps. It had not occurred to me that converting a round tube to a flat piece of copper would be that difficult. In the end, it wasn't, but it did have me scratching my head for a little while. The tubing has an .083" wall, and, I didn't think to anneal it first. Be that as it may, I managed to spread the axial cut on one wall far enough to get the tube over a piece of railroad rail. From there is was must a matter of beating it into submission with my 3 1/2 lb hammer.



After laying out the circles, I cut the squares out on my band saw, then laid 45 degree lines to create octagons.



And cut them out...



Then, using my 2" x 48" vertical belt grinder, I ground the blanks down to the inscribed circle.



Here is picture with the boiler tube sitting on top of one of the blanks...



Chuck
 

arnoldb

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Good going Chuck Thm:

Copper work is not all that bad as it's made out to be. From your other post I don't know yet if you're going to try your hand at spinning, or just plain old brute force with a BFH. With the hammer, just take your time - don't try and forge the caps in one go - a smaller hammer with controlled application actually works better than taking a couple of big wallops around the outside. Anneal often; it saves a LOT of effort. I don't know about spinning, but I have a hunch it will be the same - spin in a bit until things get tough, anneal, and repeat.

Regards, Arnold

 

cfellows

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Thanks, Arnold.

Here's a picture of my forming tool. I had a piece of aluminum about the right size, so I turned it down and radiused the edge.



Here's the first end cap roughly formed. For those of you who may have chuckled when I mentioned spinning the endcap, yeah, that was a non-starter.



And here's the first end cap turned to fit in the tube:





I'm going to take another .010" or so off my forming tool so I don't have to skim so much off the finished cap to get it fit in the tube. I couldn't seem to hammer it down to a close fit on the forming tool. I might have needed to anneal it again, per Arnold's suggestion.

Chuck
 

ironman

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Chuck looks like you are well on your way to building your boiler. Really looks good so far.
Thm:
Ray
 

Brian Rupnow

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Chuck---Thank you for this very informative post. Karma for you!!! I am not sure if I will ever build a boiler or not, but I have succesfully built a number of "compressed air" engines and a couple of I.C. engines, and I need something a bit different to build next. This post will be an asset to everyone on this forum.---Brian
 

cfellows

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ironman said:
Chuck looks like you are well on your way to building your boiler. Really looks good so far.
Thm:
Ray
Thanks, Ray, I'm pleased with the results so far. Let's hope I can take'er all the way!

Brian Rupnow said:
Chuck---Thank you for this very informative post. Karma for you!!! I am not sure if I will ever build a boiler or not, but I have succesfully built a number of "compressed air" engines and a couple of I.C. engines, and I need something a bit different to build next. This post will be an asset to everyone on this forum.---Brian
Thanks, Brian. I have always thought I would build a boiler someday, but I needed a good reason to do it. A steam powered vehicle seemed like a good motivation. Hopefully this will be one more thing I can cross off my "Bucket List"!

Chuck

 

steamer

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Good looking fit there Chuck...that'll be a breeze to silver solder

Dave
 

Maryak

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Chuck,

Great start on the boiler :bow: :bow:

I have the copper, I have the silver solder, now all I need is the inspiration, a revamp of my intestinal fortitude and a new skill set.

Good onya mate.

Best Regards
Bob
 

doubletop

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Chuck

They are looking good, get them in the pickle and they'll really look the part. Don't mess with sulphric acid, cirtric acid from the home baking section in the store will do it.

If you have any misgivings about the silver soldering can I suggest you make a couple more and do a test piece. You can never have enough end plates as you'll be using any extra on your horizontal boiler (believe me you'll be making one)

Pete
 

Brian Rupnow

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I would like to know more about pickling. When do you do it, why do you do it, and who do you do it to? I used to have an uncle who was pickled most of the time.---Seriously, I do need to know a lot more about pickling. I don't want to mess up Chucks boiler thread, so I will start a new "pickling" thread.---Brian
 

doubletop

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Brian

Pickling removes all the oxides and gunk in readiness for soldering. I may be wrong here but I keep everything I've made in the pickle as I make it. That way its ready to go at assembly time. It goes back in after every soldering operation ready for the next one.

I wouldn't be so sure about doing that with a sulphuric acid pickle but take the view that if I can consume citric acid a bit of copper isn't going to come to much harm. (though don't try drinking your pickle) ;D

Pete
 

cfellows

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doubletop said:
Brian

Pickling removes all the oxides and gunk in readiness for soldering. I may be wrong here but I keep everything I've made in the pickle as I make it. That way its ready to go at assembly time. It goes back in after every soldering operation ready for the next one.

I wouldn't be so sure about doing that with a sulphuric acid pickle but take the view that if I can consume citric acid a bit of copper isn't going to come to much harm. (though don't try drinking your pickle) ;D

Pete
Thanks, Pete. What's the story on the horizontal boiler in you avatar? What size is it and did you build it from plans?

Thx...
Chuck
 

doubletop

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Chuck

The boiler in my avatar is posted here on HMEM http://www.homemodelenginemachinist.com/index.php?topic=9553.0. I drew the plans up myself after reading a lot of boiler related books, especially a KN Harris book that had an example of a Scotch boiler

The drawings are also posted here http://www.homemodelenginemachinist.com/index.php?action=tpmod;dl=item285

I must say that the burner could do with some further development. There are plenty of boilers around with a similar horizontal flue, (but not folded). It's probably just a case of cloning their design, or maybe providing a blower type of setup, as in loco boilers, that will help to provide the necessary draw until the system heats up and the exhaust can be used to augment the gas flow.

Hope that helps you with yours. Looking forward to the soldering phase.

Pete
 

terryd

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Brian Rupnow said:
I would like to know more about pickling. When do you do it, why do you do it, and who do you do it to? I used to have an uncle who was pickled most of the time.---Seriously, I do need to know a lot more about pickling. I don't want to mess up Chucks boiler thread, so I will start a new "pickling" thread.---Brian
Hi There,

Pickling is used to clean the surface of the metal to remove scale and oxides before soldering. It should also be used after every anneal as scale on the surface of the metal can be beaten into the surface and is then difficult to remove and can be very disfiguring as well as causing soldering problems. Repeated pickling should cause no problems with the metal as very little is dissolved in the pickle. I would also suggest using citric acid as well, sulphuric can cause rusting in the workshop even when at the high dilution used for pickling. I attach a photo of a small boiler tube (for a small oscillating engine) which shows the effect of cleaning by using a short pickle in citric acid ready for fitting the end plates. (The tube is made from sheet which has a folded seam not a simple lap joint.)

By the way, the process of shaping copper around a former is a form of 'raising' which is a method of forming hollow shapes in copper used by coppersmiths.

Regards

Terry

side view boiler.JPG
 

cfellows

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I picked up some citric acid powder locally so I'm set, for the moment, with pickling ingredients. I've temporarily stopped work on the boiler until I firm up a decision on the overall vehicle design this boiler and the engine will go in to. I'm shopping ebay for RC parts for the chassis and axle, so I may still go with a horizontal boiler depending on what I wind up with.

Chuck
 

GWRdriver

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Chuck,
terryd above mentions pickling after every annealing to remove accumulated oxide scale, and scale is most definitely a consideration, and one can certainly go through multiple pickle cycles to get rid of it. But my technique for years has been to plunge the bits into the quench as quickly and as near red-hot as possible. This produces a thermal shock and steam which will blast away almost all surface scale and leaves the parts mechanically clean and ready for more pounding. The copper often remains discolored, which can be pickled away if you like, but all the loose scale is gone (and can later be found in the bottom of the quench bucket.)
 

Blogwitch

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Chuck,

Before fitting your inner bottom plate in position, you really need to decide on whether you are going to be gas or spirits firing.

The reason being, gas burners usually take up a lot less height than a spirit one.


John
 

cfellows

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The burner will most likely be gas, although I'm sure the burner design and build is going to require a lot of research and hunting down materials. However, I'm leaning toward horizontal again, because of the the vehicle designs I'm considering.

Chuck
 

doubletop

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GWRdriver said:
But my technique for years has been to plunge the bits into the quench as quickly and as near red-hot as possible. This produces a thermal shock and steam which will blast away almost all surface scale and leaves the parts mechanically clean and ready for more pounding.
I think you are suggesting doing this at the bashing raising stage, prior to doing any soldering but I don't think its recommended once soldering has commenced. I think I was reading the Johnson Mathey instructions on silver soldering and they advise not to quench as it severely compromises the quality of the joint.

Pete
 
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