SWEETENED CONDENSED MILK—SEALING 113 
the can. This seal is very simple. but is not very strong and 
not hermetically tight. In the case of the Gebee seal, a rim pro- 
jects around the opening of the can. After the cap is inserted, 
it is crimped over this rim by means of a series of revolving dies. 
This seal is reasonably strong but not hermetically tight. The 
Sanitary can is entirely open at one end when filled. The cover 
or end is crimped around the periphery of the body of the can 
by means of revolving dies. This seal is reasonably strong 
and usually hermetically tight. The chief advantages of the 
seals without solder le in the saving of labor and the reduction 
of the cost due to the omission of solder. 
Soldering Devices and Machinery. 
—The sealing of all solderless seals is 
done by specially constructed sealing 
machines. 
Fig. 44. Soldering stove 
Courtesy of Arthur Harris & Co. 
For seals with solder there are sey- 
eral machines on the market but much 
of this work is as yet done by hand. 
For this. different types of soldering 
coppers are in use and the copper tips 
are heated in soldering stoves or pots. 
Some soldering coppers have hollow 
circular tips with a diameter equal to 
that of the cap used. The hollow tip ig. 45. A coavenient de- 
is telescoped by a rod which holds the — Vice for soldering by hand 
cap in place and the periphery of the tip fits into the groove 
of the opening of the can, where it melts the solder. A rapid, 
neat and leakless seal can be made with this instrument. 
Ordinary soldering coppers with a blunt point, such as are in 
