This is a short extract from MAINSTEAM MODELS "The Complete Guide to Miniature Steam" which is available on CDROM or by internet download.
In my opinion, there seem to be only two basic types of model steam boat: steam powered river launches with the steam engines exopsed for all to admire, or closed in scale or semi scale steam powered models. When buying secondhand ones, even if they look good to the untrained eye, it can sometimes be a problem. This is no problem if you are just a collector of vintage pond launches for static display purposes only, but if you actually want to sail your steam boat, then make sure that you are not just buying a pile of unusable junk.
If you are buying a model steam boat on Ebay, you will need to study the photographs very carefully for obvious tell tale signs of damage or abuse. If the photographs are poor, why not email the seller for some better ones? Some sellers know nothing about model steam boats so if you need to, always ask the seller some questions regarding the item before you bid on it. A reputable seller will always answer your questions. It is worth a quick look at the seller's feedback from other Ebay members before bidding on the item anyway.
Some elderly "Pond Launch" type of model steam boats, whether "open type" or "closed in type" can be really grim when you look closely at them. Sometimes the internal hull is even rotten or cracked, or both! with the oil & water residue having been repeatedly left in the boat over the years. The internal mechanics of the steam plant can be very poor. Corroded brass fittings, usually visible with a white residue around them. Cast iron steam engines are likely to be rusty, or even seized up internally (please see my guide about cast iron steam engines) "Cremated" steam boilers that leak, often with crude soft solder repair attempts are very common in old free running Pond Launch boats, so bear in mind that you will not be able to sail at your local club unless the boiler is safe & has a valid test certificate, which can be issued by the club's boiler inspector.
The types usually available are:
Open Steam River Launch
Scale, or Semi Scale Model Boat with removable superstructure with fully enclosed steam engine & boiler.
Open Steam Boats:
My personal preferences are for an open launch type of model steam boat, usually gas fired, owing to the ease of operation, plus you can see all the moving parts working as you sail the boat past yourself. Also, the boiler water level is always visible. This is a very important part of sailing a model steam boat. One consideration is cleaning up after a run. Again, I find that an open steam boat with a one piece removable steam plant is the best option. Steam engines, especially model ones can be very messy when running. The oil & water residue needs to be cleaned out of the model boat after every sailing session. A coal fired model stam boat is an interesting concept, but you need lots of experience with model steam plants to make this a practical proposition.
"Closed in" Steam Boats:
Although the thought of a large steam powered scale model ocean liner, like a "Titanic" or any other live steam scale model ship or tugboat may be attractive, it needs to be thought out before you commit yourself to buying one.
The first rule of any model boat, steam or otherwise, is that it has to run reliable in the water. The electric boat fraternity often seem to have trouble with the radio control units, speed controllers & motors. In live steam, any mechanical failure of the steam plant is not just a case of loss of power & lack of movement in the water, but positively disastrous if the boiler subsequently runs dry.
One of the problems with having a gas fired steam plant fitted in an enclosed boat, is the provision of adequate ventilation for the gas burner. It is usual to leave out some of the superstructure glazing in order to allow sufficient oxygen for couple combustion of the gas. This can spoil the scale effect of the model, so the choice of air inlet has to be considered very carefully.
Once the steam plant is lit & steam is raised, all the superstructure needs to be designed so that quick fitting & removal is possible. Time is of the essence, the longer it takes to fix in place the delicate superstructure, the less actual sailing under steam you will actually have. Cleaning the oil residue from the superstructure after a sailing session can also be time consuming & it is often all too easy to break bits off the delicate superstructure when either preparing to sail or cleaning the model. It is often difficult to fit a "one piece" steam plant in such a model, so cleaning up after a run can take time. It is very important in an enclosed boat, that the radio equipment is in a separate compartment. Electrical radio control equipment or electric cabin lights mixed with heat, steam, oil & water is not a very good combination!
The main problem with a closed in model boat, is the inability to monitor the boiler water level. If your boat runs out of water in the middle of the lake, and you do not have control over the gas feed valve by radio control, then a "Viking Funeral" effect may ensue!
On any model boat used for live steam, it is very important to make sure that the internal structure of the boat is 100% waterproof, as oily soggy wood is likely to distort & even rot away over time. Many coats of polyurethane varnish on the woodwork of an open steam launch seems to do the trick, but with an enclosed model boat, I also recommend using glass fibre to coat the internal surfaces of the hull & also the superstructure. The water & heat can easily caus the both the hull & superstructure to warp.
So there you have it - the choice is yours.
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