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[rats]

 seen this on Westbourne's site

          http://www.westbourne-models.com/#4757X0

[Ian Robins]

Hi,
It looks very much like the SVS engines that Tony Green Steam now has the rights to. Also it says in the description that the boiler is made of brass, and the MPBA recommends that boilers made of brass should not be used. If the insurance you use lets you use brass boilers the price doesn't seem to bad.
robbo
NDMBC

[andywright]

So what should boilers be made of? I thought they were allways brass or copper.
Andy

[tobyker]

Copper or something even more sophisticated - eg Nicrofer stainless steel. In some cases apparently the zinc can burn out of the brass leaving you with a boiler made of copper sponge. Not, I should have thought a problem at Mamod-type pressures (under 30 psi?) and spirit lamp or esbit firing,  -  but not for blowlamp firing or superheating. I must get my ST oscillating twin going (no not the pre-war one - one I cobbled up)

[kayem]

So what should boilers be made of? I thought they were allways brass or copper.
Andy

Copper is best for boilers, no question about that, but brass is cheaper and can be more or less OK. The problem is that 'brass' can be made from various of combinations of metals, there's no strict legal definition, and the best is a mixture of copper and zinc about 60:40, but some alloys have tin or even aluminium added, and the results can be a bit unpredictable. The usual problem is that the zinc content corrodes in time, and this causes pinholes in the boiler, they would fail a pressure test. Graupner are a strange company. Essentially they are just a huge warehouse in Kirchheim unter Teck, which is near Stuttgart. They make practically nothing themselves. almost everything is made for them in places like Kazakhstan and Uzbekistan (which I may have spelled wrong). These boilers probably work fine when new, they may work OK in two or even five years time, but I wouldn't put my own money on it. A friend's Company buys stuff from one of the old Russian Republics, so I have some idea of the labour costs involved. Graupner's profits on that steam engine must be astronomical.

[Bunkerbarge]

Another major difference though and the reason why copper alloys are used in all sorts of marine heat exchangers is that copper (398k) conducts heat almost 4 times as well as brass (110k) does, measured at 20 deg C.

Making a model boiler out of brass is going to use a hell of a lot more heat to warm up the water!

[bogstandard]

I made a Krick Victoria as soon as they were available, and this had a Wilesco gas fired steam plant in it with a brass boiler.
Within a very short time the centre flue sprung a leak, the reaction with the gas had 'leeched' out the zinc and when I put my finger up the flue it just pushed a hole through inside, it was tissue paper thin.
So beware of gas fuelled brass boilers.
The boat was subsequently fitted with a copper boilered Puffin plant with no further problems.