70 ROUGII-AND-TUMBLE ENGINEERING 



too far you may spread the Hue sufficient to crack it, 

 or you are more liable, by expanding- too hard, to spread 

 the hole in the flue sheet and thereby loosen other Hues. 

 You must be careful about this. When you think you 

 have expanded sufficiently, hit the pin a side blow in 

 order to loosen it, and turn the expander about one- 

 quarter of a turn, and drive it up as before. Repeat this 

 operation until you have made the entire circle of flues. 

 Then remove the expander, and you are ready for your 

 beader or calking tool. It is best to expand all the flues 

 that are leaking before beginning with the beader. 



The beader is used by placing the gauge or guide end 

 within the flue, and with your light hammer the flue 

 can be calked or beaded down against the flue sheet Be 

 careful to use your hammer lightly, so as not to bruise 

 the flues or sheet. When you have gone over all the ex- 

 panded flues in this way, you will, if you have been care- 

 ful, have a good job. A little practice, and you will be- 

 come quite an expert. I never saw a man go into a fire- 

 box and stop the leak but that he came out well pleased 

 with himself. The fact that a firebox is no pleasant work- 

 shop may have had something to do with it. If your 

 flues have been leaking badly, and you have expanded 

 them, it would be well to test your boiler with cold water 

 pressure to make sure that you have a good job. 



How are you going to test your boiler? If you can 

 attach to a hydrant, do so, and when you have given your 



