Model Boat Mayhem
The Shipyard ( Dry Dock ): Builds & Questions => Steam => Topic started by: Henk Goosen on October 22, 2012, 07:29:57 am
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I build this wobbler engine and I would like to build a vertical boiler. My question is can I use brass for a boiler?
(http://s14.postimage.org/p2qns9pxp/French_wobbler_011.jpg) (http://postimage.org/image/p2qns9pxp/)
Henk.
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Yes, but only for low pressure applications- 1Bar or less really. Brass can de-zincify at steam temperatures, as well as being difficult to silver solder as the melting point of thin brass is very close to soldering temperature.
It can be done, has been done and you can do it too, but I would recommend copper.
Greg
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Thank you Greg. :-))
The reason for brass is that the tube comes with endcaps. Soldering copper is almost like soldering silver and I have done a fair share of silversmithing.
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I don't agree: if you use at least a quality of MS63 then you can use brass also for higher pressure applications (3Bar). BUT: you have to make sure that you empty the boiler if you are not going to use it for a longer time. The main risk for de-zincify is when there is water in the boiler for a longer time. The boilers of German manufacturer Regner for instance are all made of brass since more than 20 years. Although I have not been always satisfied with his products (used to have a "Premium" plant in may Galsgow paddler) Regner has quite a good reputation especialy for his live steam locos. Conclusion: in case weight is a matter than I would consider a brass boiler, otherwise rather copper.
Kaspar
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Kaspar thank you for your reply.
I noticed that more commercial boilers are made of brass , Wilesco uses brass to.
Henk.
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Hi the best Brass boilers are from seamless solid drawn Tube
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wilesco is definitely for low pressure only. as far as I know they are soft soldered only. best regards kaspar
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I don`t want a wilesco boiler but build one or buy a regner boiler. There is a supplier that sells seamless brass tube with a diameter of 70mm and 90 mm and has endcaps to.
For that little wobbler I need two bar presure max three bar.
Henk.
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Henk,
One of the problems in giving a definitive answer to your question is that there isn't enough known about silver soldered brass boilers and of the regulations required in Holland to hydraulic test and give a Certificate for insurance.
In the U.K. if you produced a brass boiler to a tester to be Certified you would require to produce design drawings, design figures of the brass tube from the manufacturer on it's strength and integrity and calculations to prove that your design was safe other wise he would refuse to hydraulic test it and issue a certificate for insurance purposes..
In all of the years in testing Copper boilers I have never come across a new brass boiler made by an amateur boiler maker for testing nor do I know where design calculations for a brass design are available, so in general I would not test it.
I don't know where you live in Holland, city or country, so if you are not concerned about having an insurance certificate to cover any accidents or personal injuries with your boiler go ahead and make it in brass.
Just be careful on soldering as it's already been said that the melting point of brass is near that to silver solder and the heat required you could alter the mechanical property's of the brass and if the gauge is quite light you could in the worst case burn a hole in the tube or change the brass structure to become very brittle which will not be noticable until under pressure when it could all give way.
Don't under estimate 1 bar of pressure, it can do serious damage if you are near a boiler at that pressure when it lets go, there is a You-Tube vid some where of a small brass boiler blowing and it's quite frightening, maybe some body can post the link to it.
Remember that Wilesco, Regner and others who make and sell steam plants buy such large quantities of brass tube that they can specify from the tube makers what gauge and make up of the tube is and have been making them for years.
I would strongly suggest that if you wish to make your own boiler make it in copper which is a very well known and proven material for the amateur boiler maker.
Calculations are available ( see the K.N.Harris book MODEL BOILERS and BOILER MAKING ) as are proven designs for copper boilers and safer in the long term.
Don't let us put you of with your brass boiler but be very careful
George
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George thank you very much for your comment :-)). I have thought it over and decided to buy a regner boiler.
Regards Henk.
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George thank you very much for your comment :-)). I have thought it over and decided to buy a regner boiler.
Regards Henk.
Henk,
I hope that your enthusiasm to build a boiler has not been dampened, why not consider building one in copper, can the supplier of the brass tube supply you with a piece 1 mm thk x 75 mm dia copper tube or thinner ?
You will then need some flat copper plate to make the end plates and the formers from some hard wood, a small vertical boiler with a center flue and a ceramic burner or some fuel cubes would be ideal for your little engine.
I don't know what the cost of a Regnar boiler would be but you could cost it against materials to build your own which will be much cheaper and think of the satisfaction of bashing copper with a big hammer, it gets rid of a lot of frustration.
George
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George I am going to have a look at the Regner boiler this boiler is about € 100.00 the cost of materials is about € 75.00.
I still have to build a Launch. By buying a boiler I have more time to build a Launch and finish my two cylinder wobbler.
Henk.
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George I am going to have a look at the Regner boiler this boiler is about € 100.00 the cost of materials is about € 75.00.
I still have to build a Launch. By buying a boiler I have more time to build a Launch and finish my two cylinder wobbler.
Henk.
Thanks Henk,
It's hardly worth building your own at this point as the price differential isn't too much and as you say by purchasing one it lets you push on with the boat.
Look forward to your engine and boat build.
George.
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The engine looks like this:
(http://s8.postimage.org/fk72c6h75/wobbler_001.jpg) (http://postimage.org/image/fk72c6h75/)
Was at the hobby store and discussed the boiler I had in mind, but he sugested to buy a bigger one or buikd one. He showed a plan for a 80 mm boiler from copper.
He told me where to buy copper pipe and I left the store with a bag of fittings :-)
Henk.
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Greetings Henk, could you please provide a link to the page showing the Regner boiler you were considering? For those of us who do not have the facilities to build a boiler it sounds like the boiler you were looking at would be a well priced one for the smaller engines. Thanks, Ian.
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Ian it is a Dutch company that has the Regner catalog on line http://modelbouwatelier.nl/ (http://modelbouwatelier.nl/) than you go to producten/occasions, than Regner stoommachines micro and easyline. The boiler I was looking at is a small one just good enough for a wobbler. It is the blue one.
Henk.
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condenser under construction
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Thanks for the guide Henk, I have bookmarked the page for when I have my next small project under way. Cheers, Ian
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Your welcome Ian.
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Boiler building.
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so what happened here did you build the boiler?
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Henk, this may be of interest to you.
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Mike the boiler is finished, building a gas tank now.
Hammer thanks nice pictures. :-))
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Refinishing
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so where's the photos then <*<
cheers :-))
vnkiwi
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Tried it Kiwi but I think i`m doing somthing wrong <:(
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Can you email the photos to Martin, the mod's, or another member, who could post them for you?
cheers
vnkiwi
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picture
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Looks nice, but one can hardly see details because the picture is so small. Can't you upload a bigger one?
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I bet you are happy you did it yourself now aren't you. Well done.
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KNO3 I am happy that I uploaded this picture it is not my piece of cake {:-{ .
hammer thanks for your reply and yes it is very satisfactory to be this close to running I am building the gas tank but at the moment I am in the hospital. Hopefully I may go home tomorrow.
Henk.
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They don't let us build Gas tanks in our hospitals. %%
Regards Ian.
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Henk.....we wish you a speedy recovery :-)) ....take it easy & post some images & text on your boiler build when you get a chance ..........Derek
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Ian I produce so much gas that I have to build a gastank :-)) .
Thanks Derek, When I am home and back on building I will post more pictures O0 .
Henk.
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Remember very high pressure in a gas tank.
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Here are a few pictures
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Looks very nice
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Thanks KNO3!
The gas tank