A. The water not coming in contact with the patch, it would soon bulge from the heat and crack.
Q. Why patch it on the inside?
A. Because the action that has weakened the plate before will act upon the patch, when this is worn it can be replaced.
Q. If you found you had to put on several patches what would you do?
A. Reduce the steam pressure.
Q. If you found a blister what would you do?
A. Cut it out and put a patch on the fire side.
Q. If you found a plate buckled or sagged what would you do?
A. Put a stay bolt through the center of the sag.