Aluminum=No Good for landscape lighting

Discussion in 'Landscape Lighting' started by pete scalia, Nov 7, 2007.

  1. pete scalia

    pete scalia LawnSite Senior Member
    Messages: 960

    Picture speaks for itself

  2. ccfree

    ccfree LawnSite Member
    Messages: 100

    Nothing wrong with aluminum fixtures as long it is rust proof and the powder coat system is top notch. I have aluminum fixtures in the ground for 10 years and still look great.
  3. irrig8r

    irrig8r LawnSite Platinum Member
    Messages: 4,553

    You paint with a broad brush there Pete. I agree with you about aluminum spikes.

    When it comes to fixtures though, you should take a look at an aluminum alloy called 6061-T6. I'm not sure who is using it besides FX, but I've never had one of their aluminum alloy fixtures corrode (unlike NS, Hadco and Vista).

    This Aluminum / Silicon / Magnesium alloy has been solution heat treated and artificially aged. Machines well with excellent welding qualities. Resists stress cracking. Good formability with medium strength and high corrosion resistance. Used in many heavy–duty structures, particularly for transportation and marine applications.
  4. pete scalia

    pete scalia LawnSite Senior Member
    Messages: 960

    Maybe in california and texas but they don't survive on Long Island which is surrounded by salt water ocean.
  5. Lite4

    Lite4 LawnSite Gold Member
    Messages: 3,187

    Geez Pete, the pic looks like you dug an old cow bell out of the ground. I am sure there has got to be better grades of aluminum like Gregg is talking about. I believe Chris J. brought up one time about all the aluminum stairs, railings etc.. on boats that seem to stand up to direct salt water spray.
  6. Eden Lights

    Eden Lights LawnSite Senior Member
    Messages: 805

    FX has never had a corrosion return according to there slicks.
  7. sprinkler guy

    sprinkler guy LawnSite Member
    Messages: 223

    I don't consider myself the smartest guy in the world, but last time I checked California is on the coast. I do alot of work right on the beach, and I've serviced plenty of 7-10 year old jobs with FX aluminum fixtures that don't show any signs of corrosion.
  8. Lawn Designers

    Lawn Designers LawnSite Member
    from NY
    Messages: 11

    Companies in china applying rust proof coatings to aluminum fixtures = corrosion. I have no faith that these imports use proper rust proofing methods. Maybe they can buy paint from Matel, I hear lead doesn't corrode for decades.
  9. ChampionLS

    ChampionLS LawnSite Bronze Member
    Messages: 1,066

    Ok boys and girls.. This is a deep issue. There are MANY grades of Aluminum... not just the 'silver stuff' or the kind you wrap your lunch in. Some Aluminum will turn to dust in a very short time, such as the pic above., while others will do nothing. Then comes the issue of painting or Powder Coating. Most fixtures are Powder Coated then baked at 400*, which will protect them indefinitely. Most of the jobs you see that are corroded are OLD style fixtures. Just like with boats, the older the boat, the more corrosion on the outdrive. Anyway, I'll post what I have on Aluminum and this will help shed some light. (haha)
    Aluminum - The Most Common Grades

    1100 This grade is commercially pure aluminum. It is soft and ductile and has excellent workability. It is ideal for applications involving intricate forming because it work hardens more slowly than other alloys. It is the most weldable of aluminum alloys, by any method. It is non heat-treatable. It has excellent resistance to corrosion and is widely used in the chemical and food processing industries. It responds well to decorative finishes which make it suitable for giftware.

    2011 This is the most free-machining of the common aluminum alloys. It also has excellent mechanical properties. Thus, it is widely used for automatic screw machine products in parts requiring extensive machining.

    2014 & 2017 The 2017 alloy combines excellent machinability and high strength with the result that it is one of the most widely used alloys for automatic screw machine work. It is a tough, ductile alloy suitable for heavy-duty structural parts. Its strength is slightly less than that of 2014.

    2024 This is one of the best known of the high strength aluminum alloys. With its high strength and excellent fatigue resistance, it is used to advantage on structures and parts where good strength-to-weight ratio is desired. It is readily machined to a high finish. It is readily formed in the annealed condition and may be subsequently heat treated. Arc or gas welding is generally not recommended, although this alloy may be spot, seam or flash welded. Since corrosion resistance is relatively low, 2024 is commonly used with an anodized finish or in clad form ("Alclad") with a thin surface layer of high purity aluminum. Applications: aircraft structural components, aircraft fittings, hardware, truck wheels and parts for the transportation industry.

    3003 This is the most widely used of all aluminum alloys. It is essentially commercially pure aluminum with the addition of manganese which increases the strength some 20% over the 1100 grade. Thus, it has all the excellent characteristics of 1100 with higher strength. It has excellent corrosion resistance. It has excellent workability and it may be deep drawn or spun, welded or brazed. It is non heat treatable. Applications: cooking utensils. decorative trim, awnings, siding, storage tanks, chemical equipment.

    5005 This alloy is generally considered to be an improved version of 3003. It has the same general mechanical properties as 3003 but appears to stand up better in actual service. It is readily workable. It can be deep drawn or spun, welded or brazed. It has excellent corrosion resistance. It is non heat-treatable. It is well suited for anodizing and has less tendency to streak or discolor. Applications same as 3003.

    5052 This is the highest strength alloy of the more common non heat-treatable grades. Fatigue strength is higher than most aluminum alloys. In addition, this grade has particularly good resistance to marine atmosphere and salt water corrosion. It has excellent workability. It may be drawn or formed into intricate shapes and its slightly greater strength in the annealed condition minimizes tearing that occurs in 1100 and 3003. Applications: Used in a wide variety of applications from aircraft components to home appliances, marine and transportation industry parts, heavy duty cooking utensils and equipment for bulk processing of food.

    5083 & 5086 For many years there has been a need for aluminum sheet and plate alloys that would offer, for high strength welded applications, several distinct benefits over such alloys as 5052 and 6061. Some of the benefits fabricators have been seeking are greater design efficiency, better welding characteristics, good forming properties, excellent resistance to corrosion and the same economy as in other non heat-treatable alloys. Metallurgical research has developed 5083 and 5086 as superior weldable alloys which fill these needs. Both alloys have virtually the same characteristics with 5083 having slightly higher mechanical properties due to the increased manganese content over 5086. Applications: unfired pressure vessels, missile containers, heavyduty truck and trailer assemblies, boat hulls and superstructures.

    6061 This is the least expensive and most versatile of the heat-treatable aluminum alloys. It has most of the good qualities of aluminum. It offers a range of good mechanical properties and good corrosion resistance. It can be fabricated by most of the commonly used techniques. In the annealed condition it has good workability. In the T4 condition fairly severe forming operations may be accomplished. The full T6 properties may be obtained by artificial aging. It is welded by all methods and can be furnace brazed. It is available in the clad form ('Alclad") with a thin surface layer of high purity aluminum to improve both appearance and corrosion resistance. Applications: This grade is used for a wide variety of products and applications from truck bodies and frames to screw machine parts and structural components. 6061 is used where appearance and better corrosion resistance with good strength are required.

    6063 This grade is commonly referred to as the architectural alloy. It was developed as an extrusion alloy with relatively high tensile properties, excellent finishing characteristics and a high degree of resistance to corrosion. This alloy is most often found in various interior and exterior architectural applications, such as windows, doors, store fronts and assorted trim items. It is the alloy best suited for anodizing applications - either plain or in a variety of colors.

    7075 This is one of the highest strength aluminum alloys available Its strength-to weight ratio is excellent and it is ideally used for highly stressed parts. It may be formed in the annealed condition and subsequently heat treated. Spot or flash welding can be used, although arc and gas welding are not recommended. It is available in the clad ('Alclad") form to improve the corrosion resistance with the over-all high strength being only moderately affected. Applications: Used where highest strength is needed.

    The aluminum industry uses a four-digit index system for the designation of its wrought aluminum alloys.
    As outlined below, the first digit indicates the alloy group according tothe major alloying elements.

    1xxx Series
    In this group. minimum aluminum content is 99%. and there is no major alloying element. The second digit indicates modifications in impurity limits. If the second digit is zero, there is no special control on individual impurities. Digits 1 through 9, which are assigned consecutively as needed, indicate special control of one or more individual impurities. The last two digits indicate specific minimum aluminum content. Although the absolute minimum aluminum content in this group is 99%, the minimum for certain grades is higher than 99%, and the last two digits represent the hundredths of a per cent over 99. Thus, 1030 would indicate 99.30% minimum aluminum. without special control on individual impurities. The designations 1130, 1230, 1330, etc.. indicate the same purity with special control on one or more impurities. Likewise. 1100 indicates minimum aluminum content of 99.00% with individual impurity control.

    2xxx through 9xxx Series
    The major alloying elements are indicated by the first digit, as follows:

    2xxx Copper
    3xxx Manganese
    4xxx Silicon
    5xxx Magnesium
    6xxx Magnesium and silicon
    7xxx Zinc
    8xxx Other element
    9xxx Unused series

    The second digit indicates alloy modification. If the second digit is zero. it indicates the original alloy: digits 1 through 9, which are assigned consecutively, indicate alloy modifications. The last two digits have no special significance, serving only to identify the different alloys in the group.

    Experimental Alloys
    Experimental alloys are designated according to the four digit system, but they are prefixed by the letter X. The prefix is dropped when the alloy becomes standard. During development, and before they are designated as experimental, new alloys are identified by serial numbers assigned by their originators. Use of the serial number is discontinued when the X number is assigned.


    Temper designations of wrought aluminum alloys consist of suff ixes to the numeric alloy designations. For example, in 3003-Hl4, 3003 denotes the alloy and "Hl 4" denotes the temper, or degree of hardness. The temper designation also reveals the method by which the hardness was obtained. Temper designations differ between non heat-treatable alloys and heat-treatable alloys. and their meanings are given below:

    Non Heat-Treatable Alloys
    The letter "H" is always followed by 2 or 3 digits. The first digit indicates the particular method used to obtain the temper. as follows:
    - H1 means strain hardened only.
    - H2 means strain hardened, then partially annealed.
    - H3 means strain hardened, then stabilized.
    The temper is indicated by the second digit as follows:

    2 1/4 hard
    4 1/2 hard
    6 3/4 hard
    8 full hard
    9 extra hard
    Added digits indicate modification of standard practice.

    Heat-Treatable Alloys
    -F As fabricated
    -O Annealed
    -T Heat treated

    The letter "T' is always followed oy one or more digits. These digits indicate the method used to produce the stable tempers, as follows:
    -T3 Solution heat treated, then cold worked.
    -T351 Solution heat treated, stress-relieved stretched, then cold worked.
    -T36 Solution heat treated, then cold worked (controlled).
    -T4 Solution heat treated, then naturally aged.
    -T451 Solution heat treated, then stress relieved stretched.
    -T5 Artificially aged only,
    -T6 Solution heat treated, then artificially aged.
    -T61 Solution heat treated (boiling water quench), then artificially aged.
    -T651 Solution heat treated, stress-relieved stretched, then artificially aged (precipitation heat treatment).
    -T652 Solution heat treated, stress relieved by compression. then artificially aged.
    -T7 Solution heat treated, then stabilized.
    -T8 Solution heat treated, cold worked, then artificially aged.
    -T81 Solution heat treated, cold worked (controlled), then artificially aged.
    -T851 Solution heat treated, cold worked, stress-relieved stretched, then artificially aged.
    -T9 Solution heat treated, artificially aged, then cold worked.
    -TlO Artificially aged, then cold worked.
    Added digits indicate modification of standard practice.
  10. irrig8r

    irrig8r LawnSite Platinum Member
    Messages: 4,553

    Evening Star, I think I have a copy of that same article.
    Here's something more specific about 6061 from Alcoa:

    Alcoa Alloy 6061, a cold finished aluminum wrought product, is offered for use in applications requiring excellent corrosion resistance and anodizing response, good workability, excellent joining characteristics, good acceptance of applied coatings, and adequate machinability. Some applications include impact stock for low pressure ammunition and aerospace connectors.

    General Characteristics of Alcoa Alloy 6061

    Excellent joining characteristics
    Good acceptance of applied coatings
    Combines relatively high strength, good workability and high resistance to corrosion

    The T8 and T9 tempers offer better chipping characteristics over the T6 temper.

    Typical Uses for Alcoa Alloy 6061

    Aircraft fittings
    camera lens mounts
    marine fittings and hardware
    electrical fittings and connectors
    decorative or misc. hardware
    hinge pins
    magneto parts
    brake pistons
    hydraulic pistons
    appliance fittings
    valves and valve part

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