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Although cast aluminum is mostly maintenance free there are a few things to keep in mind that can greatly extend the life of any aluminum pieces. There are very few things that will degrade the quality or finish of your aluminum pieces; however, there are chemicals and pollutant that can cause damage. Depending on if your aluminum is painted or unfinished will determine which if any of these problems can affect you.

Painted aluminum is very durable and mostly only needs to be rinsed or wash periodically to maintain a nice clean finish. The same holds true for unfinished aluminum, with the exception of care that needs to be taken. Painted aluminum is easily scratched and can fade over time which may require the item to be painted again. Do not use a stiff bristle brush to clean painted aluminum, instead use a soft bristle tooth brush to get in smaller cracks or details of the piece and a larger soft brush for more open or flat areas. Brushes will come in handy when trying to get pollen stains off of the item. Sometimes unfinished aluminum will be coated with a clear coat and over time this clear will start to haze over and possibly crack or peel. At this point it is best to LIGHTLY sand with a fine grit paper (120 grit) or above the surface until the flaking or hazing areas are gone, it is then best to reapply a layer of clear coat following the directions on whichever product you buy. Completely unfinished aluminum usually only needs a good soap rinse every once and a while, unless you want the item to acquire the natural patine finish that will occur over time.

For aluminum furniture there are a few more things that can generally affect the appearance of your items. Soft drink stains on tables, depending on the drink can contain highly acid combinations that can eat through the aluminum. Also, some suntan lotion and oils can contain chemicals that can degrade the integrity of the aluminum surface. If the furniture is painted with a high quality and durable paint the effects of these chemicals may be less damaging than with unfinished furniture. Aluminum is hard and can after a period of time become uncomfortable to sit or lounge on, this is why many people buy or have cushions made. The other hidden aspect of cushions is that they will keep you from direct contact with the aluminum surface, so suntan lotion will not get on the aluminum and therefore not affect the item as easily.

Beyond the above mentioned items, most other problems that affect other types of materials will not come into play with cast aluminum patio furniture or aluminum statues. Common sense and a little care will ensure that you get many useful years from your product. For some more information about cast aluminum you can read this article -
Cast aluminum Information