If using a battery charger, the charger must have a minimum continuous charge of 10 amps and a fast charge of at least 50 amps and must have an ammeter built in. The amperage will be regulated by exposing more or less of the graphite or steel rod.
If using a rectifier, the minimum recommended amperage rating is 50 amps. The amperage will be regulated by means of the variable transformer (the knob) built into the rectifier.
Because the amperage rating of the rectifier refers to the capacity of a rectifier a proper question would be, "how many rings can be stripped with a 50 ampere rectifier, or a 100 ampere rectifier or a 200 ampere rectifier?" Unfortunately, this is a question to which you cannot get a precise answer, because of several variables: (A) The specific stripping solution which you use (B) The specific voltage which you use (C) The total surface area of the jewelry to be stripped.
Two people each use 200 amperes (0-18 volt) rectifier with a two gallon stripping pot. Each person has turned the voltage regulator knob until the voltmeter shows 15 volts. They each have 20 identical ladies’ rings. Each hangs their rings on a heavy copper wire, dips and shakes the rings. Because each pot contains a different formula stripping solution, one rectifier shows an ammeter reading of 100 and the other rectifier shows an ammeter reading of 15.
Two people each use a 200 ampere (0 to 18 volt) rectifier with a 2-gallon stripping pot. Each pot contains the same formula stripping solution. You give each person 20 identical ladies rings. But one person had adjusted his rectifier to 10 volts and the other has adjusted his rectifier to 15 volts. The first rectifier will draw 100 amperes when the load of rings is put into the stripping pot. The second rectifier, with the same quantity of identical rings will draw 150 amperes.
Two people each use a 200 ampere (0 to 18 volt) rectifier, each adjusted to 15 volts, each with the identical formula stripping solution in a 2-gallon stripping pot. One person puts 20 ladies’ rings (weighing a total of 60 dwt.) into the stripping pot. The ammeter reading on his rectifier is 100 amperes. The other person puts 20 ladies’ rings (which are different from the other person's rings) weighing a total of 40 dwt.) into his stripping pot. Surprisingly, his rectifier does not show a lower ammeter reading than the first rectifier. It shows a higher ammeter reading. The reason for the higher reading is that his 20 rings are made of fine filigree work so that despite their lesser weight, these rings had 50% more surface than the heavier rings.
To clear up this apparent confusion and to put the matter into a logical sense, we recommend either (A) The purchase of a large rectifier or (B) Make the following test procedure if you have a rectifier available to you: Use a 2-gallon stainless pot with a stripping solution that we recommend or with a stripping solution which has been recommended to you. From a large bunch of identical ladies’ rings, take 4 rings and strip at 10 volts. Then, take 4 unstripped rings and strip these 4 rings at 11 volts. Then, take 4 unstripped rings and strip these 4 rings at 12 volts, etc. at 13 volts, at 14 volts, and at 15 volts. Determine by examining the rings, which voltage gave you the best results. Now with the voltage determined, try different quantities of different type of rings, taking careful note of how high the ammeter needle goes in each case. For example, if a group of 4 rings draws 20 amperes and it is your desire to strip 32 rings of similar dimension at one dip, then the total draw on the rectifier will be 160 amperes. Because the action of shaking the rings in the stripping solution (which is necessary) will cause the ammeter needle to surge upwards, the reading may go back and forth between 160 and 200 amperes. In this example, you need a 250 ampere rectifier. Otherwise the rectifier would be damaged.