Paddleducks
Other Marine Models => Live steam => Topic started by: andy on September 14, 2008, 09:51:00 PM
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Hi PD´s
my little steamer named SCHONDORF now I got the model nearly finished and now I have to start with the engine equipments. Boiler is under construction, RC servos ordered, but what I need is an gas container. I have no space to integrate such a big blue bottle from CAMPINGGAZ or similar. I need a little container with about 50mm diametre and about 100mm length. Does anyone here know where to buy such a part, or have I to built it myself? Has to be light and never corrosive.
What is the preferred material?
brass?
inox?
aluminium?
Andy
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Hi PD's.....yes Andy...a 50 diameter x 100 long Gas tank complete with valving is avaible from & depending on your location.......
1) forest-classics.co.uk/bix_spite.htm ...in UK
2) JMC in France
3) Anton....Fabrice in France
4) John Hemmens....UK
They all appear as brass construction & pressure tested to 25 Bar
My gas tank was purchased from ACS ........50 diameter x 120 long ...with a dry or empty weight of 400 gm.......however I suspect it is very similar to those from forest-classics.co.uk/bix_spite.htm ..........Derek
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Hi,
thanks! But I forgot to say, that the tqank has to be very light. Seems that I need an individual construction.
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Andy,
Refillable gas tanks have to be made to specified recommendations.
They have to be able to withstand such a high pressure in case the boat catches fire, so a lightweight 'safe' version is just not possible.
I have always had my doubts about putting commercial screw on gas containers in model boats. In the event of a fire, I am sure they would not be able to prevent rupture for very long, and I would be inclined to think that the devastation range would be something like 5 metres circumference around the boat, maybe a lot more. Devastation = engulfed in flames and flying debris.
John
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Hi PD's.........Andy - the only mention of a trial of aluminium gas tanks that I am aware of is by the French modeler Daniel Bourard....& he gave up as it was not a success..... :hammer :ranting.....
http://translate.google.com/translate?hl=en&sl=fr&u=http://perso.wanadoo.fr/daniel.brouard/&prev=/search%3Fq%3Dhttp://perso.wanadoo.fr/daniel.brouard%26hl%3Den%26lr%3D%26sa%3DG
In Construction 1 or 2 from memory......No ...it appears that Daniel has taken many pages of the construction away....I will post a note to DB......
This is another good read relating to gas tanks...........Derek
http://www.bushwalking.org.au/FAQ/FAQ_Stoves.htm
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Hi,
I think, I will use inox 0,5mm für the tank. Same as I took at the 2 tanks of my model of the PS DIESSEN, with filling valves from Ronson lighters. Tthis was calculated with the TÜV- norms in Germany, and if I compare the thickness of the gas bottles in which we can sell the gas, ist is much more.
Maybe I will buy an interruptor- valve for the tube to the burner.
If the model will burn- s..t, but what to do then? I have not the weight in it for an automatically workung extinguisher!
:-)
Andreas
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Andy,
It isn't a matter of saving the boat if it catches on fire, consider that as being a total loss.
It is all about protecting yourself and spectators from what will happen if the gas tank explodes, due to insufficient strength to contain the rapidly expanding, highly flammable gas.
A flashback arrester isn't the solution, a very strong gas tank is.
John
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Andy,
Sandy mentioned in one of his posts that the gas tanks are tested to 350 psi hydrostatically, so unless you have the skill and experience too build equipment that can be reliably tested to that buy a commercial unit.
Regards,
Gerald
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Hi,
I will test it with about 5 atmosperes over natural earth pression, filled with water for a harmless explosion in this case. I have an compressor to do this. I donot want to loose the model, but I have to construct at the line between weight and security. I cannot make the parts as german Krupp- heavy metal.
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DO NOT USE AN AIR COMMPRESOR FOR TESTING TANKS. Tanks and boilers should only be tested hydrostatically with water and a hand pump(feed water pump), You need to test to 355Sig. 25bars that is 25 times over natural earth pressure. There is a very good article in September 2008 Model Boats by Peter Arnot that talks about tanks. You would be best to contact one of the before mentioned manufacturers and have them build a tank for you.
Regards,
Gerald
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Got in there before me Gerald.
Maybe this member doesn't really understand the consequences involved of storage of gas due to the language problem, maybe if someone could correct this by converting what has been said into German, and relaying the information that way. My German is limited to knife, fork and spoon.
John
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Maybe my English is not so good, but I can understand, what you mean here in the forum.
And I wrote, that I will fill the tank with water before testing it.
When I tested the boiler of my DIESSEN PS model I took the 8 atmospheres on it, when it was completely filled with water. And I was hidden behind 10 pieces of 25mm thik wooden plates. But nothing happened. Thickness of the boiler is 1,5mm inox. pressure in use about 2,5 atm.
What´s the problem?
Have a look to German constructions: Reliable, but heavy and not creative.
French: Creative, light, intelligent..... Compare German and french historic and modern weapons, or cars, or ships.....
So the construction of this little tank will be done like French, with a little bit of German security.
Remember the gas tanks we buy for camping, or lighters. their tank made of aluminium never is more than 0.5mm thick.
I will have made a calculation before construction. I like to survive for some years.
Andy
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Sorry Andy, I wasn't demeaning you, but in your previous post it looked like you hadn't understood our pounds per square inch.
I think you need to look at the German regulations concerning boiler and gas tank construction, you just might find the rules and regulations very similar to ours. Finding them is the major problem, but you must find out what is required by law.
I know that everyone thinks that they can make and run things as they please, but you might also find that not complying to the official specifications leaves you open to the full might of the law, also I would doubt if you would get the necessary insurance to operate an unqualified build from non standard materials. In which case, if an bad accident did happen, you would be on your own, with maybe a few million euros being stripped from your assets to pay for the damage to people and property.
You cannot quote in a court case that other gas can manufacturers only have thin casing, it is up to yourself to follow the rules, and produce a container that is made to recognised specifications. Maybe gas can manufacturers have a special licence to produce items that can easily blow the public apart, but I don't think you do.
I am not being sceptical or demeaning, just putting the facts into a straighforwards way for understanding.
You will do as you please, as it seems you are following your own route anyway, but by ignoring posts of a few concerned people, you are leaving yourself at the mercy of fate.
It will never happen! How many times have you heard that before? The Titanic rings a bell.
John
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Hi John,
these gas tanks of myDIESSEN model were calculated by an engineer for atomic plants according to the german laws, and boiler, too. NOW I take the same material dimensions and tank and boiler as well are about 2/3 of the diameter of the old ones. So securitiy means minimal 30% more. Believe, that I do not want to have an accident with the model, but I like to optimize my constructions.
In 1975 when I started to built the PS DIESSEN´s model engine, I also had to minimize weight, so this horizontal engine I made with a weight from about 1000grams. And it runs fine, is very stiff, but comarable model engines of this time had a weight of about 2500 grams. So I hade to decide if I could optimize weights without making a bad construction, or to have a submarine paddler.
So my decision always is to integrate optimal and creative constructions into my models to make them swim and move.
Is a similar job as my job as architect. Customer has no money, and I have to reach the goal with little money and good architecture. So I have to start my brain and not to waste materials.
Sorry!
And: I do not like laws, taxes........
Andreas
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Hi Everyone
Only just found this topic, and the attitude of this member is quite disturbing and something I feel strongly about and the comments I make later need to be said. Nickel Silver is the only other material other then copper that can safety be used for amateur builders of gas tanks, commercial camping gas tanks are made of steel and the valves are probably made to blow out above a certain temperature and pressure, both steel and stainless steel (inox) have to be joined by coded welders but copper and Nickel silver can be silver soldered. the UTS of nickel silver 50000psi has opposed to coppers 31908psi so tanks of 20 swg could be used, 16 swg for copper, at present one British manufacturer uses nickel silver and has boiler tester we test them, though most of the small model marine boiler do not come under the boiler test codes they are done for insurance purposes.
Now far the serious bit!!
The blatant disregard for proper engineering practice in this regard will 'EFFECT US All' and it will only take one serious accident and we will all be banned from sailing our steam boats in public places, it has taken us years to get to the status quo we have at present and the stupid efforts of one or two individuals who obviously have no ideal of proper engineering practise and put aesthetics and creativity above common sense and safety will ruin it for us all.
GAS IS DANGEROUS IT CAN AND WILL KILL IF NOT TREATED WITH RESPECT
Paul R
Boilertester
PS
I could have put this a lot stronger but this is a web site for all ages.
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Interesting banter flowing freely on topic of gas container. My learnings from time in volunteer fire brigade were that LP gas when changing from liquid to a vapour, expands to 273 times its original volume in a hurry. When a gas cylinder explodes, it is known as a "BLEVE" Boiling Liquid Escaping Vapour Explosion, also translated as Bloody Loud Extermely Violent Explosion.
Pressure vessels of any type are not for messing with, stick with proprietry lines and save weight somewhere else.
Misterbee
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Hi PD's ...& welcome Paul R.....the Boiler Tester.. :whistle... steam is a popular subject.. :hammer @ PDs' & I am sure your experience & future comments will be appreciated by many
With respect to one clarification...we understand that brass should not or be preferred for steam pressure vessels or lines...due to the leaching of zinc ...however no such issue exists with LP gas tanks......certainly my ACS/BIX tank is of brass shell & dished ends as is I understand the French range by ANTON & JMC ....the use of brass for such manufacture etc ....
regards Derek :beer
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Hello Andy,
I've build 15 steamboats until now and for the most I've made the boiler and gas tanks by myself.
I made a pressure test of 25 bar with water, this should be sufficient. I never got problems of leaking or even exploding.
It is very improbabel, that the gas tank will explode, even when the temperature would reach more than 70 degree Celsius, but far more probable is, that the seals of the Valves will leak. So it's very important to have attention of the sealings.
All my gas tanks are made of brass tube of 1 mm strenght, the diameter is between 30 to 50 mm, lenght between
40 to 120 mm. Of course all tanks are silver soldered.
If you pay attention to this points there should be no problem of leaking or exploding.
Very good finished gas tanks you can get also from Regner in Aurach.
regards
Tom
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If you view John Hemmens website be aware that It does not respond to Fire Fox as a web browser. Like several other sites, the web designer assumes that you will be using internex explorer. Pity really.
Vin
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Hi Derek
Brass is fine for commercial tanks, Nickel silver is tolerated, but for home made tanks only copper is acceptable in the UK and are usually made of 16g or 1.5mm thick material, other countries may be different and people need to check with there governing bodies, in the UK these are 'The Southern Federation of Model Engineering Societies, Northern Association of Model Engineers and Model Power Boat Association'.
Cheers
Paul R
Boilertester
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I think the important part is the hydrostatic test, as noted in the photo 375psi, and the butane propane mix.
Regards,
Gerald
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Hi PD's...... :gathering......we must question the text & % in my Gas Certificate below & I wonder if the original grammer was courtesy of that Willie Shakeshpere?
Propane not to exceed 30%
Butane not lower than 70%
I don't understand how either of the requirements.....could vary from the given when read as %' áges...but then I am of First Fleet convict stock :yeahbaby..........& we didn't have trig tables....slide rules or calculators in 1880's on our luxury cruise :vacation to OZ ........Derek .....:whistle
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Hi Derek,
I have seen and used cans with the following mixes:
Propane 30%
Butane 70%
Propane 20%
Butane 80%
Propane 25%
Butane 75%
Propane 15%
Butane 85%
Propane 40%
Butane 60%
The first four could be used with your container, the last one would be a no no.
Regards,
Gerald
PS I have just looked and the only ones I currently am using are ;
Propane 30%
Butane 70%
Butane 100%
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:whistle PD's & thanks Gerald....I have purchased disposable gas cannisters from K Mart, Bunnings, & also priced them @ a large Sporting gear wharehouse.......& the only offering was the 70/30 ratio
The cans from Bunnings are Australian produced & cost x TEN fold of the Korean produced examples from K Mart........I had no idea any other ratio existed.............Derek :coffee
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Hi,
outside of the gas tank discussion:
Is here somebody who can give me an information for a good and hot gas burner for the soldered (inox parts were melted together, no silver, no tin, I do not know the right word) inox boiler of my model? Because the engine and the boiler flaming tube are so near together, I need a burner very short for gas (butane/propane). The tube for the gas to the burner needs a 90 °fitting at the burner. What´s available on the market?
light, short, hot, uncomplicated, intelligent? (no girl) :-)
Andy
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Did you try http://www.dampfmodellbau-keifler.de/ ?
He makes custom tanks and ceramic burners too, so just send him the dimensions you need.
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No, I did not know this link, seems good! But has not what I need.
Some other links?
Andy
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Sorry, don't know others. But try asking him if he can make what you need. He makes custom parts too.