[sswee]

The point I was trying to make (and get someone to confirm my theory on) is that the current does not have to be fixed, and you can, for example, double the current and half the time required because the 720 rule is a FORMULA based on amp-minutes per square foot. Sage

No the current density does not have to be fixed to get good results. The 720 rule works and is a useful tool due to the ability to change current densities. Cutting run times are not the only reason for changing current densities. If the part is too large to do at 6 ASF with the power supply available, a drop to any current density down to 3 ASF would render equal results. Some may need to reduce CD due to running a small tank and the part being on the verge of too large for the tank. This sometimes creates to much heat for the tank to dissipate. Dropping to a lower CD will lower the heat being generated and usually make the run possible. The only reasons to go to a higher CD are shorter run times and smaller pore sizes(more to smaller pore size than just a higher CD). There are many more reasons to drop to a lower CD. Whichever is the case, the 720 rule will work. The old saying of, you can have cheap or you can have fast but you cannot have cheap and fast, comes into play. Anodizing is like many other things in that a good job can be done and great results can be had for a reasonable amount of money at the expense of time. If time is a more valuable, you are going to have to pay for it by spending more money on equipment.
SS