ZERO Halliburton Aluminum Cases – How It’s Manufactured – Part 2
Anodic Finish – AnodizingThe anodizing operation is a laboratory controlled electro-chemical process that applies a hard, protective coating of aluminum oxide to the surface of the aluminum shell.
The shells are first fastened to a unique holding rack which retains the shells in a particular position allowing for complete exposure and proper draining of the various solutions through which they pass in the anodic process.
Proper drainage is very important, because contamination from tank to tank would neutralize the chemicals and necessitate drainage of the neutralized tank and subsequent re-charging. Each of more than a dozen tanks contains an average of 2,000 gallons of fluid, including certain chemicals such as acid, caustic etch and deoxidizers, which cannot be dumped into sewer systems but must be tank trucked to disposal areas at substantial cost.
The actual process of the racked shells through the anodizing system necessitates transfer, by overhead crane, through 14 separate tanks. Ten of these are hot and cold water rinses ranging in temperatures from 70°F. to 200°F., primarily for chemical neutralization. Each tank also contains aereation equipment that agitates the rinse for complete decontamination of the shell.
There are four major chemical solutions through which the shells must pass in the application of the anodic finish.
They are first emerged in caustic etch solution, maintained at 110°F. by internal heating units. This solution, under time-controlled conditions, actually removes a portion of the shell surface to assure absolutely uniformly finished cosmetic appearance. The cases emerge from the tanks completely black in color, the result of the caustic action on the aluminum.
After the black oxide coated shells are thoroughly rinsed and the etch neutralized, they are submerged in deoxidizing tanks which restore the color of the units to that of buffed aluminum.
After two additional rinses, the shells are placed in the anodizing tanks, which contain a 70% sulfuric acid solution maintained at exactly 68°F. by a submerged re-refrigeration system.
As the rack is fully submerged, contact points at both ends engage electrical contacts mounted on the tank which will charge the entire rack. With a flick of a switch on pre-determined settings, the electronically controlled system activates the sulfuric acid solution with a constant 16-volt electrical charge for a period of 25 minutes. This electro-chemical process builds an aluminum oxide coating on the case shells which is impervious to dirt, stains and atmospheric conditions.
After three more rinses, the shells enter the sealing tank, where a hot (210°F.) nickel solution seals the anodic coating from the atmosphere.
One more cold rinse and final hot (200°F.) rinse , and the shells are ready for drying and transfer to the inspection area.
It is important to note that the anodizing process is so critical – both in uniformity of finish and color – that Zero installed its own specially-designed system to assure compliance with its critical quality standards.
This same process occurs on every other aluminum component which is used in an aluminum case.
From inspection, the cases then begin to take shape on final assembly lines, where all components - including the hand-sewn sailcloth linings – are hand-constructed under a multi-stage quality control and inspection system.
Final inspection includes all normal quality testing for fit, construction, etc., plus a complete 100% examination on light boards to insure that every case shell is evenly matched in color. The end result is a durable product with a contemporary style.