Metal Processing Applications

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Applications & Methods:

Product Link: R-Series



Prior to all manufacturing of products, the metal must be cleaned and processed prior to the finishing.

Metals are classified into three groups:

  1. Ferrous (iron, steel)
  2. Non-ferrous (aluminum, tin, zinc, copper)
  3. Exotic (platinum, monel)

Processing consists of altering the surfaces of the metal to:

  1. Resist corrosion, and
  2. Increase adhesion of paint

Corrosion resistance is accomplished by anodising aluminum or plating ferrous metal with a nonferrous plate. Some non-ferrous metals are milled chemically. (Actual removal of metal by chemical attack.)

Non-ferrous: mostly aluminium

  1. Anolding
Images,Metal Cleaning


Iron Phosphatising
This is done by a chemical specialty with a phosphoric acid base product. A uniform iron phosphate coating is imparted on the metal. A typical iron phosphatising processing line is: (spray or immersion)

  1. Clean
  2. Rinse
  3. Phosphatise
  4. Rinse
  5. Dry
  6. Paint

This, of course, has exceptions in that extra steps can be added. Sometimes the cleaning and phosphatising is one step. Zinc phosphatising is exactly the same except that the coating is zinc.

The coating is also known as a "substrate". It is important to realise that an acid pre-clean is required because if an alkaline cleaner is used, it will carry through to the phosphatising bath and neutralise it, and precipitate the phosphates to the bottom of the tank. Caution must be used if an alkaline pre clean is used. We do not have an acid based cleaner for phosphatising at present.

Again, this is primarily a surface coating for corrosion resistance on a non-ferrous metal with a nonferrous plate. Plastic is plated only for appearance.

Non-ferrous metals are also plated for corrosion resistance and wear. (abrasion resistance)

Prior to plating (chrome, copper, gold, etc.) the metal is cleaned with HYDROC or an acid cleaner almost always by an immersion bath. Typical process is:

  1. Clean
  2. Rinse
  3. Clean
  4. Rinse
  5. Plate (acid bath) Chromic sulfuric, hydrochloric
  6. Rinse
  7. Dry

The time involved is not very long, 10-40 minutes in each bath. (varies)


Usually done to ferrous metals prior to application of drawing oils or talc. Acid (heavy) bath that eats the surface of the metal so that the compound will stick.

Usually an interim step to further processing.


All aluminum products are either cast, stamped or extruded. To erase metal forming marks the surface is:

  1. Cleaned - alkaline (buffered) or alkaline (etch)
  2. Rinse
  3. Etched (caustic)
  4. Rinse
  5. De smutted (chromic acid)
  6. Rinse
  7. Anodised (hard coat - duranodic)

Aluminium is given a uniform oxide coating in the anodise bath (sulfuric acid) with electric current running to the metal, much the same as plating on a coating. Most non-ferrous metals particularly aluminium, are extremely sensitive to alkaline attack. Acid is used on the aluminium as a processor mostly as a "high speed buff' or brightener.

It is important to realise that we are selling a clean metal surface to be processed further.

If the surface is not clean "water-break" free, the substrate - phosphatise will not adhere, the plate will not stick and the aluminium etch will be uneven. Appearance and uniformity is critical.

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