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[Klunk]

couple of questions im being asked about steam and steam safety
a. at what temperature does the weld on a seam melt in a steam boiler?


b. if a steam boiler does loose a seam for whatever reason, how far would the steam jet go?


c. how long would it take for a steam joint take ro get to the melting point from normal operating temperature


some if these are open ended, but i need honest answers.

[steamboatmodel]

couple of questions im being asked about steam and steam safety
a. at what temperature does the weld on a seam melt in a steam boiler?
b. if a steam boiler does loose a seam for whatever reason, how far would the steam jet go?
c. how long would it take for a steam joint take ro get to the melting point from normal operating temperature

some if these are open ended, but i need honest answers.

a. If the weld on a seam or any part of a boiler melts, your model is already destroyed.
b. that depends on how long and what size the opening is.
c. a steam joint would never melt at normal operating temperature.
I have given honest answers with out trying to belittle you, but suggest you do some research before asking these type of questions.
Gerald.
Gerald.

[Klunk]

gerald, having operated a steam engine for the last 15 years i know most of the answers. i need clarification for legal reasons, thus the questions.  there are no direct answers to these due to variables.
ie for a boiler to run dry and get to the melting temp the operator must be
a. not paying attention
b. really not paying attention and an idiot to boot!


if you remember a few years ago in liverpool council banned model steam boays for exactly these reasons as someone had given false info to them
having seen a model boat boiler actually blow in real life i know it a phut not a bang
the steam jet question is variable BUT this is for a new club water  and the people asking questions are ignorant of facts. they are asking reasonable safety questions which i would prefer to be correct on rather than giving invalid or in correct info. i have already sent off 2 weeks ago, the BMPA steam pamphlets plus relevant test sections from the boiler testing book, plus waterside safety proceedures. all this is dotting the i's and crossing the T's.

[aeronut]

I'll echo what Gerald wrote and add the following -


a)  Model boilers generally aren't welded, but silver soldered.  Silver solder melts at around 630C for the low melting point stuff.
b) How long is a piece of string?
c) The average gas burner in the average model boiler probably wouldn't produce enough heat to melt any seams in a well constructed boiler.

[Steve Dean]

Klunk ...... you have my home number, I can help you with all of this. It is massively long winded to give proper answers to these questions on the forum.
I suspect you are being asked some questions by a council person re your possible use of the pool in Hemel. Typically these people ask questions based on no knowledge of the subject matter and therefore you need to be extremely careful in the answers you give, as it can easily create a situation whereby they go for the soft option of not letting you operate steam models.

I look forward to hearing from you.

[Klunk]

will do Steve. not sure your availability. i work nights so am available in the mornings or all day friday

[Steve Dean]

Klunk ........ you can call me anytime that suits you sir.

[steamboatmodel]

OK Klunk,
It becomes cleared now, I had wondered as I was typing my reply as I remembered in the back of my mind that you have been on the forum for quite a while and I wanted to reply reasonably before some one made a smart-alecky reply. I hope you can convince them that model steamboats are not floating bombs. I had a similar experience years back trying to convince a Fire Marshal the same thing at a public show. I even offered to run a boiler dry in front of him to show him, but he decided that  because we had a naked flame in the model it was unsafe.
Gerald.

[Klunk]

had a nice long chat with steve dean. clarified the points i needed and got some other gems to use. hopefully should be ok now.
what people need to realise is that although these can appear to be dumb questions, i am dealing with people who are looking fir problems, advised and misinformed by outside people who also have no idea what they are talking about. i was asked specific questions to which, as someone point out the answer is how long is a piece of string due to variables.
as most of you know im NOT new to this, but when dealing with official people, its always best to clarify the question first, to give an answer based with facts and figures.

[southsteyne2]

A PROPERLY built boiler will not fail under normal operating conditions even running out of water as the silver solder needs a lot more heat to melt so therefore the worst scenario is the cladding will catch fire and you will then have whats left of your model on the bottom of the lake .

Cheers
John

[boat captain]

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if you remember a few years ago in liverpool council banned model steam boats.

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In fact it was Wirral Borough Council who banned the use of steam at New Brighton.

[SteamboatPhil]

Klunk




We talk at Wicksteed and I will answer all your questions


Oh and it wasn't Liverpool it was Hull


Your humble servant.   

[pendlesteam]

If its a gas powered marine boiler I dont advise you run it dry, but if you do the boiler will not be affected, even with my burners and as far as I know mine are the hottest for any given jet size. How do I konw...ive tried darned hard !!

[Mark T]

If its a gas powered marine boiler I dont advise you run it dry, but if you do the boiler will not be affected, even with my burners and as far as I know mine are the hottest for any given jet size. How do I konw...ive tried darned hard !!

Almost tested to destruction - but couldn't as they are too well made 

[Geoff]

I did actually run a Cheddar Puffin boiler dry on one occasion many years ago. I was having constant flame out issues (due to oxygen starvation) so when it just stopped I wasn't surprised and was not concerned.


The first I know I had a problem was when black smoke came out of the funnels so I had to go wading and retrieve the model. Strangely it was on the 5th November and yes the water was cold! Once there I saw a small flame (candle sized) just coming through the engine room hatches so I blew it out, lifted the deck and turned the gas off.


The cladding had been char-coaled and was smouldering hence the black smoke. I just left everything alone and the boiler was still hot when I got home 35 mins later. A call to Cheddar the next day and they confirmed " one burner cannot un-silver solder one of our boilers - it's just not possible and the boiler should be fine.  The boiler was fine and went on to give many more years of service and is still in service today.


No damage to the model at all as I had insulated the boiler room so all was well.


There are lots of myths about small marine model boilers but the basic fact is they cannot explode unless you are totally and utterly stupid and use a bolt for the safety valve and even then they won't as Cheddar tried this years ago and a seam leaked and put the flame out - end of story.


The problem with an over-hot empty boiler is if you then pump in cold water as it will flash into steam. The question then is if the rate of steam production exceeds the capacity of the safety valve to vent the pressure and/or the strength of the sight glass which may act as a secondary safety valve.


Boilers are designed such that if the burner cannot be turned off the size of the safety valve will not permit an increase in pressure.


In my opinion very fast electrics are more dangerous as they can, and do leave the water and can hit spectators.


The only real thing to remember with steamis that its hot!


Cheers


Geoff

[IanJ]

I think all users & more importanley potential users of steam plants in their boats can be reassured by these latest comments with respect to the inherent safety of model boilers when correctly designed & constructed.


Regards


Ian

[steamboatmodel]

As

Geoff said the only real danger is if you try to add water to a hot dry boiler. The only Boiler I had go dry under gas was a D48 Wilesco one. It went dry just at the end of a run, was put on the table to cool down (it was not equipped with a water pump), when It was cool I added more water and noticed the water level in the sight glass was decreasing and there was water in the bottom of the boat. On inspection I found that the seam on one end cap was leaking. I resoldered it with silver bearing solder (5% silver) pressure tested it to 60psig. and it was fine

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Gerald.

[derekwarner]

What type of machine did you use to post your tiny text Gerald? ....or was it the strong drink

'As Geoff said the only real danger is if you try to add water to a hot dry boiler. The only Boiler I had go dry under gas was a D48 Wilesco one. It went dry just at the end of a run, was put on the table to cool down (it was not equipped with a water pump), when It was cool I added more water and noticed the water level in the sight glass was decreasing and there was water in the bottom of the boat. On inspection I found that the seam on one end cap was leaking. I resoldered it with silver bearing solder (5% silver) pressure tested it to 60psig. and it was fine'

[steamboatmodel]

Wow I don't know how that happened, If it was strong drink it wasn't on my end.
Gerald.