ETCH - 290

DESCRIPTION:

ETCH-290 is designed to produce a fine satin finish on all aluminum surfaces. It is highly alkaline etchant for aluminum. Product contains high percentage of caustic soda and chelator to provide effective results and long tank life. Also contains controlled foam level to regulate emission of gases produced during etching.

UNUSUAL FEATURES:

• ETCH-290 has a longer solution life than other etchants. This is due to the fact that it contains more caustic soda per pound (Sodium Hydroxide-Caustic soda is what does the etching) than conventional aluminum etchants.
• ETCH-290 provides an exceptionally uniform etch.
• This product drains rapidly and thoroughly compared to competitive etchants thus enabling high temperatures and, therefore faster etching without the danger of "dry-on" which produces selective etching.
• ETCH-290 eliminates all sludge and disposal problems.
• ETCH-290 has greater tolerance for temperature variations so that complete chelation is obtained even though temperatures of bath drops considerably as is the case many times on weekends.
• ETCH-290 prevents the formation of scale on heating coils and tank walls.

OPERATING CONDITIONS:

Typical cycle for Aluminum Etch Line:

• Pre clean in AL-2908.
• Cold water rinse.
• ETCH-290 4-6 oz. per gallon at 140º F.
• Cold water rinse.
• Desmutt, DX-232.
• Cold water rinse.
• Bright dip, anodize, conversion coating or Zincate-15.

Testing solution life by Hydrometer:

In the determination of when an ETCH-290 solution should be dumped a hydrometer may be used. As aluminum is processed, the specific gravity of the solution increases. At 6 oz. per gallon at room temperature (70 º F.) the critical specific gravity is 1.250. To continue to etch beyond this critical point is to run the danger of a sudden heavy precipitation of Aluminum Oxide. At this point the weight of the solved solids has increased to roughly 1 1/4 times the weight of the water itself!

TITRATION PROCEDURE:

• Accurately pipette 20 ml. of solution to be tested into a 250 ml. Erlenmeyer flask, add 30 ml. of water, (for most accurate analysis use distilled water.)
• Add: 3 drops of indicator (methyl orange) ; solution will turn pale orange.
• Titrate with N/1 HCL until solution changes from pale to deep orange.
• The number of mls. of N/1 HCL required is then recorded. This number multiplied, by product factor yield concentration in oz/gal., of product in solution.
• Product factor: 0.29
  Example; if 13/1 mls. of N/1 HCL are required and the product factor is 0.29, then the solution would have a concentration of 3.77 oz./gal. of product in solution.

SAFETY PROCEDURES:

• Personnel working with this product should wear protective clothing such as rubber gloves, apron, and safety goggles to prevent contact with skin or eyes.
• Avoid breathing dust or fumes.
• Should chemical contact skin, immediately flush with generous amount of water over a prolonged period of time, should skin irritation occur, contact physician.

The information stated herein is based on information and tests we believe to be reliable. The accuracy or completeness thereof is not guaranteed. Since conditions of use are outside our control, user shall, before using, determine the suitability of the product for his intended use and user assumes all risk and liability in connection therewith.