Saturday, January 12, 2013

Background

Physically, chemically and mechanically aluminium is a metal like steel, brass, copper, zinc, lead or titanium. It can be melted, cast, formed and machined much like these metals and it conducts electric current. In fact often the same equipment and fabrication methods are used as for steel.

Light Weight

Aluminium is a very light metal with a specific weight of 2.7 g/cm³, about a third that of steel. For example, the use of aluminium in vehicles reduces dead-weight and energy consumption while increasing load capacity. Its strength can be adapted to the application required by modifying the composition of its alloys.

Corrosion Resistance

Aluminium naturally generates a protective oxide coating and is highly corrosion resistant. Different types of surface treatment such as anodising, painting or lacquering can further improve this property. It is particularly useful for applications where protection and conservation are required.

Electrical and Thermal Conductivity

Aluminium is an excellent heat and electricity conductor and in relation to its weight is almost twice as good a conductor as copper. This has made aluminium the most commonly used material in major power transmission lines.

Reflectivity

Aluminium is a good reflector of visible light as well as heat, and that together with its low weight, makes it an ideal material for reflectors in, for example, light fittings or rescue blankets.

Ductility

Aluminium is ductile and has a low melting point and density. In a molten condition it can be processed in a number of ways. Its ductility allows products of aluminium to be basically formed close to the end of the product’s design.

Impermeable and Odourless

Aluminium foil, even when it is rolled to only 0.007 mm thickness, is still completely impermeable and lets neither light aroma nor taste substances out. Moreover, the metal itself is non-toxic and releases no aroma or taste substances which makes it ideal for packaging sensitive products such as food or pharmaceuticals.

Recyclability

Aluminium is 100 percent recyclable with no downgrading of its qualities. The re-melting of aluminium requires little energy: only about 5 percent of the energy required to produce the primary metal initially is needed in the recycling process.

Source: European Aluminium Association

How long does it last

Cedar fences are made with cedar, that Sterling Fence Ic, Eden Prairie, Mn uses which is a wood that is very strong and resistant to rot, moisture and damage from insects. Cedar can withstand weather elements and doesn't shrink and swell like many other types of wood. All these qualities help cedar fences last for up to 20 years. Does this Spark an idea?

Why Wood??

THE LIFE CYCLE OF WOOD Sterling Fence Inc

Stage 1 - Resource Extraction
Harvesting and removing the resources and transportation of the material. This includes the logging or mining required to retrieve the materials, the equipment used, the building of roads to transport the materials and reforestation efforts. Why Wood?
Harvesting wood has been shown to be much less intrusive than the mining of raw materials for steel and concrete such as iron ore, coal and limestone. And advancements in technology have even improved the process.
Stage 2 - Manufacturing
Preparing the material for use and measuring the amount of energy needed for raw materials to be manufactured into building materials. This includes the cutting of the trees into the different sizes (2x4, 4x6, etc.), and manufacturing steel and concrete from ore and minerals.
Why Wood?
Compared to a wood 2x4, a steel stud requires 21 times more energy to produce and releases more than 15 times the sulfur dioxide. Producing concrete emits up to three times more carbon dioxide, carbon monoxide and hydrocarbons than manufacturing lumber.

Stage 3 - On-Site Construction
Building with the selected materials, including delivering of the materials to the distribution centers, home centers, or building sites and the actual construction of the home.
Why Wood?
Wood requires very little on-site energy or special machinery to construct.

Stage 4 - Occupancy/Maintenance
Living in the home continues to impact the environment, including the energy needed to heat and cool your home throughout the year.
Why Wood?
Wood is a 400 times better insulator than steel and eight times better than concrete. Using wood framing will insure that your house stays cooler in the summer and warmer in the winter.
Stage 5 - Demolition
This stage assesses future impacts that are possible long after a home is lived in, including bio-degradability or reusability of materials during renovations or possible razing.
Why Wood?
Wood is a completely natural building material that's 100% biodegradable. Some wood is even recycled for use in engineered wood products.

Stage 6 - Recycling/Reuse/Disposal
Today's sustainable forestry practices ensure a perpetual abundance of cedar from North America's forests.
Why Wood?
Cedar siding substitutes like concrete, vinyl and aluminum are manufactured from materials extracted from the earth - once removed, they can never be replaced. When substitute sidings age beyond their useful life, they become part of landfills. As a natural product, cedar is fully biodegradable.

Watch the BC Sustainability Video

Members of the Western Red Cedar Export Association provide western red cedar to Belgium, France, The Netherlands, United Kingdom, Australia, New Zealand, China, Japan and other markets around the world.

Web site design by Graphically Speaking in Vancouver

Beauty of Cedar

For centuries builders and artisans have valued Western Red Cedar for its natural beauty and durability.

Cedar - Beautiful and versatile

Wonderful spectrum of natural colours.
Versatile uses.
Easy finishing.
Natural preservative.
Distinctive aroma.
Acoustic insulation.
Architectural design.

Colours - Unfinished cedar has richly textured grain with colours ranging from mellow ambers, reddish cinnamons and rich sienna browns. Its warm coloring is complimented by a uniform, fine-grained texture with a satin luster.

Usages - Cedar is ideal for siding, decking, moulding, windows, doors, posts, beams, paneling outdoor projects, cladding, interiors and saunas.

Easy finishing - Because cedar is virtually pitch and resin free, the wood easily accepts a range of finishes, from fine oils and stains, to solid coatings and paint.

Natural preservative - Cedar contains natural preservatives that resist moisture, decay and insect damage.

Aroma - Cedar's unique aroma comes from naturally occurring thujaplicins in its heartwood. These compounds are toxic to decay-causing fungi and preserve the wood to give it long lasting appeal.

Acoustic insulation - Acoustic properties of cedar walls and ceilings provide sound insulation necessary to quieten rooms.

Architectural design - Cedar compliments any architectural design - from turn-of-the-century to contemporary.

Addtional properties of Cedar

Durability
Historically, native peoples of the Pacific coast prized cedar for its long lasting qualities and used wood and bark from cedar trees for most of their building needs. Evidence of cedar's durability are the many cedar artifacts still in good condition today.

Properly finished and maintained, cedar will deliver decades of trouble-free service. If exposed for prolonged periods to conditions where decay could be a factor, such as where the wood is in contact with the ground, cedar should be treated with suitable wood preservatives.

Fastening
Western Red Cedar has good fastening properties but its natural preservatives have a corrosive effect on some unprotected metals in close contact, causing a black stain on the wood. Fasteners should be corrosive resistant such as aluminum, brass, silicon bronze, hot-dipped galvanized or stainless steel.

Nails and screws used to fasten Western Red Cedar should be about one-third longer than those used to fasten hardwood species.

Because it is free of pitch and resin, Western Red Cedar has excellent gluing properties, comparable to those, for example, of old growth Redwood and American Chestnut. It works well with a wide range of adhesives.
Finishing
Although cedar is a naturally durable species, leaving it untreated is not recommended because a finish or protective coating will greatly increase its service life. Cedar is free of pitch and with its high degree of dimensional stability, it is the best of the softwoods for accepting paints, stains, oils and other coatings. For a detailed discussion, see Finishing Western Red Cedar published by the Western Red Cedar Lumber Association.
Workability
With its straight grain and uniform texture, Western Red Cedar is among the easiest and most rewarding woods to work with. It takes a fine finish in all hand and machine operations, takes fasteners without splitting and is easily sawn and nailed. When working with Western Red Cedar, sharp cutters are recommended.
Products, Grades and Sizes
There are few more versatile building materials than Western Red Cedar which is ideal both for indoor and outdoor uses. Western Red Cedar lumber is available in visual stress grades for construction and finishing uses in a range of lengths, widths and thicknesses. It is available in clear or knotty grades with smooth surfaced, combed or rough sawn finishes; kiln dried or unseasoned (green); flat grain and vertical grain.

Western Red Cedar is used to manufacture a range of specialty products such as siding, paneling, structural decking and outdoor decking. Detailed product information is available from the Western Red Cedar Export Association.

Cedar produced by the Western Red Cedar Export Association includes specialty end use grades as well as products graded to National Lumber Grading Authority (NLGA) rules. NLGA grades are approved by the American Lumber Standards Board of Review and are accepted under all US building codes.

Western Red Cedar (Thuja plicata) is one of North America's great renewable resources. Slow growing and naturally durable, Western Red Cedar has one of the longest life spans of any North American softwood. It produces long lengths of timber with true, straight grain. It is free from pitch and its heartwood has natural decay resistance. Its low density gives it an insulation value superior to most other species. Light weight, easy to work, easy to finish, possessing outstanding dimensional stability, Western Red Cedar is a preferred wood for nearly all purposes where attractive appearance or resistance to weather is important.

Features of Western Red Cedar

Acoustic properties:	Cedar tends to dampen sound transmission
Density (oven-dry):	22 lb/ft3
Specific Gravity (oven dry):	0.35
Durability:	Durable species
Fasteners:	Corrosion resistant only (aluminum, hot-dipped galvanized, brass, etc.)
Finishing:	Paints, stains, varnishes, oils and waxes all work well
Flame spread rating:	69 (class II)
Smoke developed classification:	98
k value(12% mc):	0.74 BTU inch/square ft.h degrees F
R value:	1.35 in. of thickness
Stability:	Cedar is the most stable softwood species
Workability:	Easy to cut, saw, nail and glue

Comparative Softwood Densities (pcf)

Species	Oven-Dry Density
Western Red Cedar	22
Douglas Fir	31
Ponderosa Pine	27
Southern Pine	34

Shrinkage of Western Red Cedar

Direction of Shrinkage	Shrinkage in Percentage
	From green (25% or greater moisture content) to:			From kiln dried (15% average moisture content) to:
	15%	12%	6%	15%	12%	6%
Radial	0.96	1.2	1.8	0	0.3	1.0
Tangential	2.0	2.6	3.8	0	0.7	2.1

Notes:

Radial shrinkage applies to the width of vertical grain lumber: tangential to the width of flat grain lumber.
Shrinkage does not begin until the fiber saturation point is reached.
15% is the average equilibrium moisture content of wood during the summer in the Pacific Northwest.
12% is the summer average equilibrium moisture content in dry areas of the Pacific Northwest.
6% is the average equilibrium moisture content for interiors of heated buildings.

Web site design by Graphically Speaking in Vancouver

Properties of Cedar

Density
One of the lightest commercial softwoods, the density of Western Red Cedar at oven-dry conditions is approximately 22 pounds per cubic foot with a relative density (specific gravity) of 0.35. Comparative oven-dry densities of cedar and some other softwood species are given in the table below. Cedar's low density enhances its insulation value and makes it an easy wood to transport and handle.

Dimensional Stability
Like all woods, Western Red Cedar is hygroscopic and will absorb or discharge moisture to attain equilibrium with the surrounding atmosphere. However, it has a very low shrinkage factor and is superior to all other coniferous woods in its resistance to warping, twisting and checking. The size differential between dry and unseasoned Western Red Cedar is given in the table below. Shrinkage in both the radial and tangential directions is given in the table below.
Thermal Conductivity
Wood is an excellent thermal insulator. This is an important characteristic since good thermal insulators help keep buildings cool in the summer and reduce heating costs in the winter.

The conduction of heat in wood is directly related to its density. Woods with low density have the highest thermal insulating value because such woods contain a high proportion of cell cavities. In dry wood, these cavities are filled with air which is one of the best known thermal insulators.

With its low density and high proportion of air spaces, Western Red Cedar is the best thermal insulator among the commonly available softwood species and is far superior to brick, concrete and steel. It has a coefficient of thermal conductivity (k value) at 12% mc of 0.74 BTU in. per square ft.h degrees F. The R value (the reciprocal of k) for Western Red Cedar is 1.35" of thickness.
Accoustic Properties
An important accoustical property of wood is its ability to damp vibrations. Wood has a cellular network of minute interlocking pores which converts sound energy into heat by frictional and viscoelastic resistance.

Because of the high internal friction created by the cellular pore network, wood has more sound damping capacity than most structural materials. Floor, ceiling and wall assemblies of wood can provide effective economical sound insulation and absorption when properly utilized. Western Red Cedar is particularly effective in this regard and can be used to help reduce noise or to confine it to certain areas.
Flame Spreading Ratio
Flame spreading ratings describe the surface burning characteristics of interior finishes. They are used to regulate the use of interior finish materials to reduce the probability of rapid fire spread. Materials are burned in a test furnace for a relative assessment of flammability. The lower the flame spread rating, the more the material resists the spread of fire.

Building codes in North America generally define as interior finish any exposed material that forms part of the building interior. This usually includes interior wall and ceiling finishes, flooring, windows, doors and other wood products. US codes set the maximum flame spread rating for interior wall and ceiling finishes in most buildings at 200. The flame spread rating for Western Red Cedar is 69 (Class II rating).

Smoke developed classifications reflect the amount of smoke

Thursday, January 10, 2013

Metal protection

In current use, the term refers to the coating of steel or iron with zinc. This is done to prevent rusting of the ferrous item. The value of galvanizing stems from the corrosion resistance of zinc, which, under most service conditions, is considerably greater than that of iron and steel. The zinc serves as a sacrificial anode, so that it cathodically protects exposed steel. This means that even if the coating is scratched or abraded, the exposed steel will still be protected from corrosion by the remaining zinc - an advantage absent from paint, enamel, powder coating and other methods. Galvanizing is also favored as a means of protective coating because of its low cost, ease of application and comparatively long maintenance-free service life.

The term galvanizing, while technically referring specifically to the application of zinc coating by the use of a galvanic cell (also known as electroplating), is also generally understood to include hot-dip zinc coating. The practical difference is that hot-dip galvanization produces a thick, durable and matte gray coating - electroplated coatings tend to be thin and brightly reflective. Due to its thinness, the zinc of electroplated coatings is quickly depleted, making them unsuitable for outdoor applications (except in very dry climates). When combined with subsequent painting (which slows zinc consumption), electroplating is durable enough to be used in some premium auto body coatings.

Nonetheless, electroplating is used on its own for many outdoor applications because it is cheaper than hot dip zinc coating and looks good when new. Another reason not to use hot dip zinc coating is that for bolts and nuts size M10 (US 3/8") or smaller, the thick hot-dipped coating fills in too much of the threads, which reduces strength (because the dimension of the steel prior to coating must be reduced for the fasteners to fit together). This means that for cars, bicycles and many other 'light' mechanical products, the alternative to electroplating bolts and nuts is not hot dip zinc coating but making the bolts and nuts from stainless steel (known by the corrosion grades A4 and A2).

Electroplated steel is visually indistinguishable from stainless steel when new.^{[citation
needed]} To determine whether a part is electroplated or stainless steel, apply a magnet. The most common stainless steel alloys (including those used for bolts and nuts) are not magnetic or only very slightly attracted to a magnet.

[edit] History

Originally, "galvanization" was the administration of electric shocks (in the 19th century also termed Faradism, after Michael Faraday). It stemmed from Galvani's induction of twitches in severed frogs' legs, by his accidental generation of electricity. Its claims to health benefits have largely been disproved, except for some limited uses in psychiatry in the form of electroconvulsive therapy (ECT). This archaic sense is the origin of the meaning of galvanic when meaning "affected/affecting, as if by a shock of electricity; startled".^[1] and the metaphorical "galvanize into action" referring to suddenly stimulating a complacent person or group to take action. Later the word was used for processes of electrodeposition, which remains a useful and broadly applied technology. But the term "galvanization" has largely come to be associated with zinc coatings, to the exclusion of other metals.

Galvanic paint, a precursor to hot-dip galvanization, was patented by Stanislas Sorel, of Paris, France in December, 1837.^[2]

The earliest known example of galvanizing of iron was found on 17th century Indian armor in the Royal Armouries Museum collection.^[3]

[edit] Zinc coatings

Main articles: Hot-dip galvanizing and Sherardizing

Zinc coatings prevent corrosion of the protected metal by forming a physical barrier, and by acting as a sacrificial anode even if this barrier is damaged. When exposed to the atmosphere, zinc reacts with oxygen to form zinc oxide, which further reacts with water molecules in the air to form zinc hydroxide. In turn, zinc hydroxide reacts with carbon dioxide in the atmosphere to yield a thin, impermeable, tenacious and quite insoluble dull gray layer of zinc carbonate which adheres extremely well to the underlying zinc, so protecting it from further corrosion. This is similar to the protection afforded to aluminium and stainless steels by their oxide layers.

Hot-dip galvanizing deposits a thick robust layer that may be more than is necessary for the protection of the underlying metal in some applications. This is the case in automobile bodies, where additional rust proofing paint will be applied. Here, a thinner form of galvanizing is applied by electroplating, called "electrogalvanization". The hot-dip process slightly reduces the strength of the base metal, which is a consideration for the manufacture of wire rope and other highly-stressed products. The protection provided by this process is insufficient for products that will be constantly exposed to corrosive materials such as salt water. For these applications, more expensive stainless steel is preferred. Some nails made today are electro-galvanized.

As noted previously, both mechanisms are often at work in practical applications. For example, the traditional measure of a coating's effectiveness is resistance to a salt spray. Thin coatings cannot remain intact indefinitely when subject to surface abrasion, and the galvanic protection offered by zinc can be sharply contrasted to more noble metals. As an example, a scratched or incomplete coating of chromium actually exacerbates corrosion of the underlying steel, since it is less electrochemically active than the substrate.

Galvanized surface with visible spangle

The size of crystallites in galvanized coatings is a visible and aesthetic feature, known as spangle. By varying the number of particles added for heterogeneous nucleation and the rate of cooling in a hot-dip process, the spangle can be adjusted from an apparently uniform surface (crystallites too small to see with the naked eye) to grains several centimetres wide. Visible crystallites are rare in other engineering materials.

Thermal diffusion galvanizing, a form of Sherardizing, provides a zinc coating on iron or copper based materials partially similar to hot dip galvanizing, but the final surface that results is different from that yielded with hot-dip galvanizing in that all of the zinc is alloyed.^[4] Zinc is applied in a powder form with "accelerator chemicals" (generally sand,^[5] but other chemicals are patented). The parts and the zinc powder are tumbled in a sealed drum while it is heated to slightly below zinc's melting temperature. The drum must be heated evenly, or complications will arise. Due to the chemicals added to the zinc powder, the zinc/iron makes an alloy at a lower temperature than hot dip galvanizing. This process requires generally fewer preparatory cleanings than other methods. The dull-grey crystal structure formed by the process bonds more strongly with paint, powder coating, and rubber overmolding processes than other methods. It is a preferred method for coating small, complex-shaped metals, and for smoothing in rough surfaces on items formed with powder metal.

[edit] Eventual corrosion

Rusted corrugated steel roof

Although galvanizing will inhibit attack of the underlying steel, rusting will be inevitable, especially if exposed to the natural acidity of rain. For example, corrugated iron sheet roofing will start to degrade within a few years despite the protective action of the zinc coating. Marine and salty environments also lower the lifetime of galvanized iron because the high electrical conductivity of sea water increases the rate of corrosion. Galvanized car frames exemplify this; they corrode much quicker in cold environments due to road salt. Galvanized steel can last for many years if other means are maintained, such as paint coatings and additional sacrificial anodes.

[edit] Galvanized piping

[edit] See also

Cathodic protection
Corrugated galvanized iron
Galvannealed - galvanization and annealing
Sendzimir process
Sherardizing

[edit] References

^ "Galvanic; Dictionary.com". http://dictionary.reference.com/search?r=10&q=galvanic. Retrieved 2006-11-30.
^ Process for protecting articles made of Iron or Steel from oxidation." Specification of patent granted to M. Sorel, of Paris, France, December, 1837. Journal of the Franklin Institute (Philadelphia, Pa.), Published by Pergamon Press, 1838, via Google Book Search.
^ [1] Summary of XRF analysis conducted on or about 30 September 1999 by the Royal Armouries Museum in Leeds and written up as part of a thesis by Helen Bowstead Stallybrass at the Department of Archaeological Sciences, Bradford University.
^ Presentation on Thermal Diffusion Galvanizing: http://www.armycorrosion.com/past_summits/summit2009/09Presentations%5CDay3%5CMosheMoked.pdf
^ Porter, Frank C. (1991). Zinc Handbook. CRC Press. ISBN 978-0-8247-8340-2. http://books.google.com/books?id=laACw9i0D_wC&q=sherardizing&cad=6#v=snippet&q=sherardizing&f=false.

[edit] External links

Look up galvanize in Wiktionary, the free dictionary.

Wikimedia Commons has media related to: Galvanization

American Galvanizers Association

Retrieved from "http://en.wikipedia.org/w/index.php?title=Galvanization&oldid=530540541"

Categories:

Hidden categories:

Chain Link Fence Installation

All posts (including line post) are set in concrete approximately 24” deep and a hole that is 6” in diameter.
Posts are spaced along the fence line not more than 10’ apart.
The wire is stretched to proper tension for maximum strength.
Setting of all posts is the first part of fence construction. The post will set in the concrete for several days before the rest of the fence is assembled, the fabric stretched, and the job completed.

Located in the Minneapolis and St. Paul area, Sterling Fence, Inc. offers a free chain link fencing quote.

Get Started Today!

Get a Free Quote

Call: 952.888.6843

Download Our Product List

Ornamental Fence Installation

All posts (including line post) are set in concrete approximately 24” deep and a hole that is 6”-8” in diameter.
Posts are spaced along the fence line not more than 6’-8’ apart.
Fences conform to the contour of the ground and posts.
Good fences must be straight and clearing obstacles in the way is important. We inspect the ground during bid quotation and modify the building of the fence if necessary. All types of dirt, clay, sand, black dirt, peat, and gravel are taken into consideration.

Located in the Minneapolis and St. Paul area, Sterling Fence, Inc. offers a free ornamental fencing quote.

Get Started Today!

Get a Free Quote

Call: 952.888.6843

Download Our Product List

Our framework is 16 gauge with the Ameristar PermaCoat powder coating system, and its double layer of protection. The base coat is a epoxy moisture barrier which is thermally fused to the galvanized substrate and is reknowned for its outstanding corrosion resistance. The finish coat is a thermo-setting TGIC no-mar polyester top coat with enhanced UV resistance to maintain a beautiful color finish for a lifetime of maintenance-free enjoyment. Ameristar offers a 15-year warranty against cracking, chipping, peeling, blistering and corroding.

Wednesday, January 9, 2013

Wood Fence Installation

Our installation crews take pride in their craftsmanship. We have many referrals and repeat customers. On privacy and picket fences, we set post approximately 3’ in the ground (8” diameter footing) and cement top 2/3’s so post do not rot prematurely.
Fences conform to the contour of the ground and posts. Gates are custom fabricated at the job site, with heavy decorative hardware being used. Good fences must be straight and clearing obstacles in the way is important.
We inspect the ground during bid quotation and modify the building of the fence if necessary. All types of dirt, clay, sand, black dirt, peat, and gravel are taken into consideration.
Located in the Minneapolis and St. Paul area, Sterling Fence, Inc. offers a free wood fencing quote.

Get Started Today!

Get a Free Quote

Call: 952.888.6843

Download Our Product List

Sterling Fence Inc.
13480 Pioneer Trail
Eden Prairie, MN 55347
952.941.2213 — Office
952.888.3316 — Fax
MN CONTRACTORS LICENSE #0005011
We are insured and licensed to operate in the state of Minnesota.