A. Yes, if the work is done carefully. See full explanation previously given, [p. 17]. Great care should be taken not to expand the flues too much, for by so doing you are likely to loosen other flues and cause more leaks than you had in the first place. Small leaks inside a boiler are not particularly dangerous, but they should be remedied at the earliest possible moment, since they reduce the power of the boiler and put out the fire. Besides, they look bad for the engineer.
Q. How should flues be cleaned?
A. Some use a steam blower; but a better way is to scrape off the metal with one of the many patent scrapers, which just fill the flue, and when attached to a rod and worked back and forth a few times the whole length of the flue do admirable service.
Q. What harm will dirty flues do?
A. Two difficulties arise from dirty flues. If they become reduced in size the fire will not burn well. Then, the same amount of heat will do far less work because it is so much harder for it to get through the layer of soot and ashes, which are non-conductors.
Q. What would you do if the throttle broke?
A. Use reverse lever.