Mcr,
One thing you shouldn't do with such a small boiler is to feed too much water, as you can soon overwhealm the burner and so the boiler starts to cool down, with obvious results.
The boiler you have should give you about 20 to 25 minutes steaming, what you should aim for is to extend that steaming time to say 40 to 45 mins before the boiler reaches say 1/4 full. By that time, you will most probably need to top up the lubricator and give the engine an external lube and a rest.
When we used to sail our steam boats, we found that we didn't need to go any longer than a normal fill of 20 mins, as we were ready for a rest, chinwag, cup of coffee and a smoke break. Four or five sailings on a sunny afternoon we found just perfect, and maybe only two in the winter.
Just enjoy.
Bogs
