Q. In case the boiler flues become leaky, can they be tightened?
A. Yes, by the use of a tool called an “expander,” which is generally
kept in stock by the boiler manufacturer.
[Illustration: Prosser’s Spring Expander.]
Q. Can an unskilled person expand and tighten the flues of his boiler
without the aid of an expert or boiler maker?
A. Yes, if he is careful and follows these instructions, viz:
First clean the ends of the flues and flue sheet of all dirt, soot and
cinders, and place the expander within the leaky flue, being careful to
have the shoulder of the tool well against the head and end of flue.
Now, with a light hammer drive in the taper expanding pin and after
two or three blows of the hammer, jar the pin out, turn the expander
a little and drive in pin as before, removing the pin and turning
expander again until a full turn has been made.
Great care must be taken in expanding flues not to expand them so hard
as to stretch or enlarge the hole containing flue in the flue sheet,
thereby loosening the adjoining flue. After all the loose flues have
been carefully expanded, take the beading tool and place the long or
guide end within the flue, then with the aid of a light hammer the ends
of flues can be gradually beaded or calked against the flue sheet,
rendering them perfectly tight. With a little practice, a careful man
can do a neat job of calking, thereby avoiding loss of time and expense
in being obliged to call a boiler maker. An expander and calking tools
should be among the tools of every engineer, as many little leaks that
may occur in a steam boiler, although they may not be dangerous, give
it a bad appearance and should be calked and stopped by the engineer.