no not at all... quite the opposite actually
Anodising is (simplest explanation) an electrical coating of the alloy much the same as chrome plating is, in the case of alloy, the anodising process forms a layer of aluminium oxide - Al203 (corundum), which is very hard, relatively inert, electrically insulating (which is why its suitable for salt water use
), and can absorb dyes to colour the alloy.
there are 3 main types of anodising.....
Sulphuric Acid Anodising -> used mainly for hard working areas where heavy use and wear n tear would normally cut down the protective surface in a short period of time, EG outdoor furniture, window frames etc etc
Hard Anodising -> significantly harder, thicker, denser films with a higher resistance to wear, corrosion, temperature effects etc.... your cars engine-bay will have components treated at this level
Chromic Acid Anodising -> These coatings are thin, and relatively soft and generally only used in specialised applications, the name plate on the trophies in your cabinet are chromic acid anodised.... good for looks and not much else
for beams on a boat, then the SULPHURIC ACID ANODISING is the best, its also the most commonly used form of anodising https://www.youtube.com/watch?v=O0GQPHh3Szk