You might consider using a current limiter (an active device, not a resistor) and limit the current to 1 to 1.5 ma per square inch of electrode (anode) surface area. Larger surface areas would allow for faster brew times. Even if you want to brew at higher current densities, there comes a time when the current is excessive for any cell when you reach a high concentration, so you may want to limit the maximum current to some level.
Try using a pump or stirrer that moves only water rather than anything that using air. I believe that brew rates well above that 1.5 ma per square inch area are possible with faster stirring. I'm not sure what I think about the CS with H2O2 added *after* brewing compared to CS made well without adding any H2O2. I know there is some change, but is it more beneficial than just leaving it the way it was? I also feel that longer brew times waste silver since you can calculate the amount of silver put into the solution and compare the calculation to the uSiemens reading. Perhaps the residue goes into particles or is attached to the cathode. With polarity switching the particles would go into the solution. However, people that brew with very, very low current densities don't seem to have any losses on the cathodes to speak of, as far as I know. I never did any calculations to compare with a system such as this. You should take your current readings more often initially (for any cell with changed conditions) and graph the results. Use the Excel program Faraday Calculator to calculate your maximum concentration or at least the amount of liberated silver. How big is your cell (how much water volume)? 140 mm (5.5 inches approx) is pretty wide electrode spacing, many people use a closer spacing, but I don't think that a closer spacing will give better CS, just let the process start up faster. Dan -----Original Message----- From: Phil and Carol Conway [mailto:[email protected]] Sent: Monday, October 09, 2006 5:21 PM To: Silver List Subject: CS>How to make the best CS? I have made CS for some time. Power: I use old HP printer power supply giving 36 volts DC, regulated and a 1900 ohm series resistance to limit the power to the electrodes. I have tried an 18 volt DC un-regulated supply too, but had better results on 36 volts. I use a recycling timer to reverse the electrode polarity every 5 minutes (approximately) to reduce the need to clean the wires. Electrodes. I use 3 pairs of electrodes -140mm long, 1.8 mm gauge of 99.999 % pure silver. I get better results with the greater electrode area of silver wire in the distilled water ( It tests at 000 ppm). The spacing between the electrode assemblies is 140 mm. I use a small aquarium air supply, and valves and 3 mm tubing to feed air up by the electrodes. I get best results using about ten bubbles a second rising from two tubes positioned at the sides of each electrode group. I have tried more air, and small tubes of a plastic mesh to "contain" the rising air bubbles close by the electrodes - but with little benefit. I record time, mA, volts across the electrodes, and ppm of silver ions. I determine the amp/seconds over time. From the data I calculate the silver atoms liberated. (One ampere/second liberates 6.25E+18 atoms of silver.) I compare the total amp/secs with the silver ion test at 5.5 to 6 hours and between 10 and 12 ppm of silver ions. Such comparisons indicate clearly that higher series resistances waste silver. Lower resistances may give a further improvement, but I have not conducted the necessary experiments. I use a small red laser pointer to see the Tyndall Effect due to the presence of silver atom groups in the solution. This allows me to assess the amount of brightly reflecting particles and the effect of adding a few drops of hydrgen peroxide (27%)on them. I also assess the size of the great many smaller atom groups that are present ( I appreciate the smallest atom groups probably do not reflect sufficient light to be visible). I am looking for information to help me to produce a better colloidal silver product; ie one with a good quantity of ionic silver and small particle-groups of silver atoms. Thank you Phil -- The Silver List is a moderated forum for discussing Colloidal Silver. Instructions for unsubscribing are posted at: http://silverlist.org To post, address your message to: [email protected] Address Off-Topic messages to: [email protected] The Silver List and Off Topic List archives are currently down... List maintainer: Mike Devour <[email protected]>
