ADJUSTING THE SEAMING ROLLS

If bubbles rise from the can the seam is not sufficiently tight.  If this seam is not sufficiently tight the second seaming roll needs adjusting, provided the directions regarding seaming rolls given below have been observed.  To set the rolls proceed as follows:  Loosen the nut on the bottom of the seaming-roll pin.  With a screw driver turn the seaming-roll pin counter clockwise—­that is, from right to left.  Turn very slightly and, while holding the seaming-roll pin with the screw driver in the left hand, tighten nut with the right hand, and test as before.

Occasionally it is well to compare the seam after the first operation with the sample can which is sent with the machine.

If seaming rolls cut into the can they are set too close, and the seaming-roll pin should be adjusted in the opposite direction from above.

After adjusting, always test cans as suggested above before canning.  The seaming rolls are set before the machine leaves the factory and should not require adjusting for some time, but I have found that slight variations in cans may make adjusting necessary.

If for any reason the second seaming roll is brought into contact with the can before the first operation is complete it may injure the can seriously, thus preventing an air-tight seam.

If the first seaming roll is forced in too rapidly it may ruin the seam.  Push the seaming-roll lever gently and steadily, while turning the crank with the right hand.  This rolls the seam gradually.  There is no danger from bringing in the second seaming roll too quickly if the first seaming roll has completed its work.

There are thus, as you see, two kinds of tin cans used in home canning:  The sanitary or rim-seal can, which is used with a sealer, and the cap-and-hole can.  The latter consists of a can, and a cover which carries a rim of solder and is fastened on the can by the application of heat.

The sanitary can has a cover a trifle larger than the diameter of the can, thus leaving the full diameter of the can open for filling.  That part of the cover that comes into contact with the can is coated with a compound or fitted with a paper gasket or ring which makes a perfect seal when the cover is crimped on the can.  Some mechanical device is necessary for sealing this can, and this is the sealer.

Cans may be had with inside enamel or plain without any enamel.  The following fruits and vegetables should be canned in enamel-lined cans:  All berry fruits, cherries, plums, rhubarb, pumpkin, beets and squash.  All highly colored products should be canned in enamel-lined cans to prevent the bleaching effect induced by their action upon the plain tin.  Some prefer to can fish and meat in the enamel-lined cans.  Other products not mentioned here may be canned in plain cans, since they are less expensive than the enamel-lined cans.