Author Topic: Boiler for Marcher engine  (Read 1007 times)

Offline Moxis

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Boiler for Marcher engine
« on: December 13, 2018, 07:08:07 AM »
Hello all, Now that I have almost completed my Marcher build which is shown elsewhere here, I need a boiler to steam it. Both will be installed into a half open launch about 1.2 metres long. I have thought to use a horizontal boiler about 2,5 or 3" diameter fired with a gas burner. But should I buy a ready made boiler, a kit, or make everything from scratch?
So my question is, are there vendors for this kind of boilers or kits available? Or plans for simple copper boilers? I have rather limited equipment for silver soldering, so it may be that my soldering torch does not have power enough to heat relatively large copper tubes necessary for this kind of boilers.

Offline K.B.C

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Re: Boiler for Marcher engine
« Reply #1 on: December 13, 2018, 11:44:44 AM »
Hi Moxis,

Making your own boiler is not an easy job if you don't have the correct equipment, there is a company in the U.K. that makes and sells all types of copper Certificated boilers ( http://www.pendlesteamboilers.com/Products/ ) and I think that they will even make all the boiler bushes metric to suit your requirements ( I have no connection to this company ) but have recommended a few members of Modelboatmayhem to try them out, so have a look.
If you contact them you will find that they try their best to accommodate any special requirements.

George.
 
Your never too old to learn.

Offline Moxis

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Re: Boiler for Marcher engine
« Reply #2 on: December 13, 2018, 04:10:43 PM »
Thank you George! For sure I will contact them and ask for a quotation. Because I agree with you that fabrication of a boiler might be beyond my skills and equipment, and it will be more on a safe side just to buy one.

Offline Moxis

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Re: Boiler for Marcher engine
« Reply #3 on: March 14, 2019, 06:36:12 AM »
Finally I have got a boiler for my boat/engine. It is a horizontal gas fired 3" diameter boiler made of copper. My intention is to cover the boiler with wooden strips, like most of marine boilers seem to be made. But should I install a cladding of some sort of fabrics or cardboard under the wooden strips to isolate strips from hot copper surface?

Offline simplyloco

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Re: Boiler for Marcher engine
« Reply #4 on: March 14, 2019, 09:07:46 AM »
I have clad a number of boilers and cylinders with wooden strips held on with stainless steel or copper ties. I have never used anything underneath and the wood is a good insulator in its own right.
Best of luck.
John

Offline MJM460

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Re: Boiler for Marcher engine
« Reply #5 on: March 14, 2019, 10:51:42 AM »
Hi Maxis,

I have been following from the start and am glad that you now have a boiler to run it on steam.  It will be a wonderful power plant for the boat you have built, which I seem to remember that you showed in your very early posts.

Just to contribute a second point of view, I also have a gas fired three inch horizontal centreflue boiler and would recommend that you do place a layer of cork or other insulating material under the wooden strips.

It is not that the wood needs additional protection, so much as the heat loss is still significant with only one layer of wood.  I suspect that a second layer of wood would even do if you prefer it.  I did some experiments in my Thermodynamics thread if you want more detail.  It will also help keep the inside of the boat a bit cooler, which never hurts when you have a radio installation nearby.

The main disadvantage of making the decision at this stage is that the extra insulation makes access to filler plugs and other fittings more difficult, but just do your best around the fittings so you can tighten things up.  You will also need longer bands to hold the wood in place than if you leave off the extra layer.

MJM460


The more I learn, the more I find that I still have to learn!

Offline Moxis

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Re: Boiler for Marcher engine
« Reply #6 on: March 15, 2019, 06:17:47 AM »
Thanks John and MJM460. Good point that additional thermal insulation might help to keep the inside of the boat cooler. And a thin layer of cork under the wooden strips would be a nice option too. I think i will follow that. Now i only have to find cork which is thin enough. What thickness have you used?

Offline MJM460

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Re: Boiler for Marcher engine
« Reply #7 on: March 15, 2019, 08:15:37 AM »
Hi Maxis, I found sheets of 3 mm thick cork in a $2 shop, they were A4 size.  More than $2, that is inflation for you, but not expensive that I can remember.

I actually fitted two cork layers under the wood, but I think on balance the extra layer was more problem than it was worth, though probably worth doing if you are making a new boiler so you can make extended bushes and other fittings.  Possibly also better to specifically plan locations of bushes etc to minimise the fiddle little gaps.

MJM460

The more I learn, the more I find that I still have to learn!