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[Pat-K]

Hi Guys,


Being fairly new to the RC Model world I have recently taken possession of a very nice model of a lake steamer. The question I would like you ask you experts is on filling the gas tank, I have just brought an adapter from Cleveland Steam - I enclose a picture of my gas tank.


The questions I have are as follows :-


1. What is the best way of filling the tank without getting lots of gas spilling out and flowing everywhere.
2. Is it possible to overfill the tank.
3. When storing the model is it best to empty the tank.


The boiler in my boat is a Chedder Vertical boiler.


Any help you be appreciated for this virgin steamer


Any advise and help would be very much appreciated.






Best Regards








Pat

[rhavrane]

Bonjour Pat,

I have dozens of gas tanks, examples https://youtu.be/RXi9hN2orsc including Cheddar ones : https://youtu.be/eez9ACLowcQ and I can tell you that except "Legris" ones, they all leak a little bit, and you will know that your tank is full when liquid gas is escaping (this is why I much prefer Legris system and purge valve).

Despite this drawback, there is no risk of overfilling, and furthermore, you will open slowly your gas valve to start the burner.

Remember to ventilate your hull after filling before lighting the gas, the latter is heavier than air and will tend to stay at the bottom of the hull with the risk of a nice and surprising "boom" in case of accumulation.

As I also have gas regulators and RC safety gas valves, I never purge my tanks and thus save a few cents that become euros for more than 60 tanks     

Last detail, all my gas pipes are made of copper or brass and silver soldered to avoid any melting due to an unexpected heat source.

[pipercub1772]

Always remove the tank from the model before filling ,A good thing to do is weigh the tank empty , It gives you a starting point  ,And most gas tanks only take between1 and 5 ounces to fill, I find it better to have the gas tank  colder than the one thats going to fill it, Also that can help having some silicone tubing on the end of the filling adaptor like rhavrane suggests in his video of filling a cheddar gas tank,Regarding leaving full tanks if youre not going to use for a long time  i tend not to for some reason i have had a couple of instances of the tanks deforming , after filling i always let some gas out of the tank to make sure you have gas coming out and not liqueid as this would could be a problem lighting, Weigh the tank when full so you know its weight ,Sounds a bit dounting at first and it is but you will get the hang of it after several attempts ,regards Allan

[1967Brutus]

Always remove the tank from the model before filling ,A good thing to do is weigh the tank empty , It gives you a starting point  ,And most gas tanks only take between1 and 5 ounces to fill, I find it better to have the gas tank  colder than the one thats going to fill it, Also that can help having some silicone tubing on the end of the filling adaptor like rhavrane suggests in his video of filling a cheddar gas tank,Regarding leaving full tanks if youre not going to use for a long time  i tend not to for some reason i have had a couple of instances of the tanks deforming , after filling i always let some gas out of the tank to make sure you have gas coming out and not liqueid as this would could be a problem lighting, Weigh the tank when full so you know its weight ,Sounds a bit dounting at first and it is but you will get the hang of it after several attempts ,regards Allan

To extend a bit more on this: It helps to first determine the volumetric capacity of the tank. I normally do this by removing the filling valve, then weigh the empty tank, fill it with water and weigh it again. Using metric, this should be pretty straightforward (every gramme of water is 1 ml of capacity) but imperial should give the same result, just different numbers.

Once you have those numbers, write them down and figure out how much liquid gas this volume CAN hold.

This will tell you the maximum possible weight of the gas-filled tank.

FWIW, LPG (30% propane, 70% Butane) has a density of roughly 0,55 g/ml but pure butane or propane are fairly similar in density.
Usually, the bottle you buy both has a net volume AND a net weight stated on the label, so it should be no problem to work out the actual density of the gas you are using.

Since liquid gas has a fairly large thermal expansion factor, I usually keep a 10% margin when fillling.

Leakage during filling is a matter of both having a decent filling adapter, and applying it as straight as possible to the filling valve. Takes a bit of practice, I guess. If I see/hear leakage. wiggling the bottle a bit usually solves that. If it doesn't, finmd a better adapter.


Never leave the filled tank in the model for reasons allready mentioned. Either run it completely empty, OR store it separately in a well ventilated place free from ignition sources.

[Pat-K]

Thank you so much for all your advise guys' - please keep any useful tips coming all much appreciated

[derekwarner]

Courtesy of the Australian manufacturer 'Minature Steam Models'...Gas Tank document discusses the filling and also the design and positioning of the 'Ronson' filling valve and the venting of liquid towards the practical completion of the re-fil


A comprehensive read & explains all there is to understand with these gas tanks   


Derek

[Geoff]

From the picture it's clear the knurled knob disconnects the tank. On one of my models I made an adaptor so the gas can be poured into the exit point. Just connect and open the valve on the givi g ta k, then open the exit valve and you can hear the gas trickling in. Easy and little gas loss.


Cheers


Geoff

[Geoff]

As an observation I note the gas tank is lagged. This may prove problematic as the gas changes state from liquid to gas it needs energy to do this so takes the heat from the surrounding air. The lagging will impede this which can lead to low gas pressure and an eratic flame. It is better to have the condenser just toich the gas tank and this provides me the warmth which maintains the gas pressure.


Cheers


Geoff