My steam tugboat

[kno3]

Hello!

I've mentioned my steam tugboat project here before, but now I thought about making a topic, because there are some things I'd like to get feedback on.

Description:

I. Hull
It is a mostly scratch built live steam wooden tugboat, mostly complete, except for smalelr details like lights, masts, bollards,
Only the hull shape comes from the St. Canute plan/kit from Billing Boats, the rest is my own design. It is plank on frame, using abachi wood strips. The darker wood used for the deck and cabins is walnut.

I have described the building process here, for those interested:
http://www.rcuniverse.com/forum/m_7166206/mpage_1/key_/tm.htm

[kno3]

II. Engine

The steam engine is a modified Wilesco D49, with vertical boiler and V-twin double acting piston valve engine. I have added a superheater (steam line going down the chimney and exiting through the fire box), lightened the con rods and added an adjustable oiler and manometer from Modellbau Niggel, and an exhaust condenser. The fuel is alcohol. The vaporising burner is my own design, using a sealed external tank which feeds the burner via a 2-way tube that keeps a constant alcohol level in the burner.

There are videos of the tugboat in action here:
http://www.youtube.com/v/6wJSdGhEffo&hl

[kno3]

Now my questions:

I've had some problems with the burner. Because the fuel lines from the tank are thin, capilarity sometimes draws alcohol into the air line and stops the burner from refueling. I've added a ire inside the air line which helps the liquid flow and let the air pass, but it seems that the setup is sensitive. It refuels the burner perfectly on the workbench, but not while in the boat.
I've also had a fire in the boat (forgot the fuel valve open while refuelling and it overflowed). I managed to put it out before anything was damaged.

All these problems made me realise that maybe my boat is just too cramped for such a capricious burner (I'll save it for another project) and that I should use a more reliable design, because a fire while out on the lake would be a disaster.

What would you recommend as a reliable design yet with enough fuel capacity for 40 minutes or so?

By the way, I don't really want to switch to gas (a nice ceramic burner is quite expensive from what I saw) and I'd prefer to build it myself. I can do basic soldering and sheet metal cutting and bending.