Arguments For And Against Aluminum Anodizing and High Solids Acrylic Clear Coating. Anodizing: Anodizing is the process of electro-chemically enchancing an aluminum surface and making it harder. In a solution of electrolyte (5% H2SO4), a direct current is applied to the anode and crystals compriced of aluminum, oxygen, and sulphur form from the virgin metal on the surface subject to the current-flux. This new material formed is referred to as anodic oxide, which is a non-conductor or at least a hi-dieletric semiconductor. Anodic oxide is one form of aluminum oxide which is a popular abrasive material. It is quite hard. It is very thin. Anodic coatings vary from 0.1 mils(.0001") to 0.7 mils(.007") for most applications. Anodic oxides are good aluminum surface protectors for commodities like windows and storefront. Anodic oxides are extremely poor at resisting abrasion from silicas and sand found in riverbank mud. This sand being harder than the anodic oxide, will remove the anodic coatings in a single footprint. It is not economically feasable to repair the anodizing. It is impractable to weld to anodizing because it is a non-conductor.
High Solids Acrylic Clear Coating: This is a common automotive finish and is available in thicknesses up to 30 mil(.030"). Acrylic transmits the beauty of the substrate through the coating and can be furnished in satin or hi-gloss. This finish will prevent the silver gray oxides from occuring on inflatable tubes. Clear acrylic is available from thousands of vendors and can be applied with little expertise. Clear acrylic paint is easily repaired with Crystal Clear Krylon available in the sub $3.00 range. Acrylic paint can be removed with MEK allowing repair or weld modifications for little cost. Since the acrylic clear thansmits the beauty of the underlying aluminum, one should use a mild cleaner and wire brush to clean affected areas prior to painting. Questions about these processes or bulk cleaners & OS-PHO solutions can be sent to sales@cataraft.net
Acrylic clear coatings are applied at room temperature. Do not confuse this with clear powder coating. Powder coating pre-heating destroys the temper of the substrate aluminum and renders aluminum frames in an annealed state. This means a 20-40% reduction in strength.