For many Americans, their favorite hobby is watching television. This may not sound like a hobby to some people, but it is. The definition of a hobby is to do some leisure or recreational activity outside of one’s career. Watching television is probably the most common hobby there is. With the amount of hours that people spend watching television each day, and it is climbing, television watching easily becomes one of the most popular activities for among Americans. I would not say that it is a constructive one, but it is a popular one. What else do people spend their time doing more? They work for eight hours a day, and then the average person watches TV for five to eight hours a day. Nobody spends that much time doing one other particular activity.

The lesson we learn from this is that not all hobbies are created equal. Some hobbies can be more constructive and enhance your lifestyle or quality of life more than others. There are an infinite number of things that you could do, which would be more constructive than watching television. Read a book, go out and do something with some friends, go do some sort of physical exercise. Find a hobby at the nearest hobby shop, that is constructive, that helps you in some way and improves your life in some way. Find something that gives you a sense of satisfaction and fulfillment, something that can give you the sense of feeling like you have accomplished something.

Most people I have talked to, who watch an enormous amount of television, admit themselves that television is boring and a waste of time. So why do they spend so much time doing it? Some people, I think, are just unaware of how much time they are actually spending. If you sit down and show them how much of their life is being spend in front of the TV, they would be surprised. Others watch television for lack of something better to do. They cannot think of things to do, or do not want to take the effort to think of better things to do. The TV has already warped their minds of creativity. They have become slaves to it, unable to act any longer on their own or think of their own things to do. Others might watch it from laziness. They just want to sit around, so why not turn on the TV while they are just sitting there. Others might watch just for a break from anything. It is kind of nice sometimes to relax your brain after using it at work or school all day. Watching TV is very relaxing to the brain. You do not even have to think; you can just sit there and stare blankly at the screen. It is great! Well, these are just things I have thought of for people spending so much time watching TV. There are probably numerous other excuses, but none of them justify the time and talent wasted on such an endeavor, talents that could be developed in other areas.

One of my favorite quotes is “money is only as good as the good that you can do with it.” I think we could say the same thing about our time. “Time is only as good as the good that we can do with,” so lets make our time useful and do something good, something constructive. Plan out your days and your weeks; plan good uplifting activities; plan something that will help you and others. TV is often just a fallback for people who do not plan other, more constructive things.

Building model airplanes or flying radio control airplanes is a popular hobby. It is something educational, and can give you a feeling of intelligence and accomplishment. There are also people who are just avid airplane fans and like to collect handcrafted mahogany airplanes, which are a little more expensive, but worth it to those are really interested in Model Airplanes. Mahogany is a fine type of wood that the planes are designed from. Many types of nice furniture are designed from mahogany. According to Webster’s Dictionary, Mahogany is wood “of any of various chiefly tropical trees (family Meliaceae, the mahogany family). When people are discussing mahogany crafts, they are most likely discussing Webster’s second definition “the durable yellowish brown to reddish brown usually moderately hard and heavy wood of a West Indian tree (Swietenia mahagoni) that is widely used for cabinetwork and fine finish work.” At any rate, mahogany is a nice type of wood to build furniture or model airplanes.

Mahogany model airplanes are hand crafted. Each plane is carved individually from mahogany wood. An is nice models for display. You can keep them on your desk in your office, your bedroom, or in the living room of your home. They are excellent for decoration. Anyone who loves airplanes or model airplanes will love mahogany model airplanes. Mahogany airplanes can be used for toys for kids, as well, albeit expensive toys. They could be a nice decoration to your child’s room or dresser though, if they love model airplanes. Mahogany model airplanes are a luxury brand of model airplane designs.

Mahogany airplanes can come in many sizes. I have seen many people with a miniature on their desks in their offices. A miniature mahogany model airplane can add to the personality of one’s office. It can add a sense of excitement to the office or work space, rather than just surrounding yourself with work related material. You can have that little plane sitting there, reminding you of better things. It can keep up your moral, and get you excited.

At Variety Access, an online hobby store, you can find a variety of mahogany model airplanes. Variety Access sells airplanes manufactured by Aircraft Models Corp. Aircraft Models Corp. does all of the hand craft designs and paint for all of its planes. At Variety Access, you can find hundreds of selections of model aircraft in categories including World War I era planes, World War II model airplanes, civilian aircraft throughout the twentieth century and current civilian aircraft, commercial aircraft, and world record aircraft. They also have miniature mahogany aircraft that accentuate a home or office. You could even hang them in your car if you like. There are aircraft models and sizes to satisfy any interest or personality.

Collecting model aircraft, especially high quality, hand crafted mahogany model airplanes, can be a fun, interesting and constructive hobby that anyone can enjoy. Whether you are interested in just hand craft wood objects, airplanes in general, or history, model airplanes may be the hobby for you. Model airplanes can show the history of our world with planes from every era of the twentieth century; planes that fought in every war; planes that someone you know fly in or have flown in. I personally like the big civilian aircrafts the most; the large commercial Boeing model airplanes. I would also be interested in collecting world record aircraft models, from the first flight, to the first flight across the Atlantic, to the fastest flight and finally, the space shuttle flights into space.

Perennial landscaping benefits greatly from easy to grow plants. Here we will look at some of those which can be used with great effect, for landscaping, with details such as their height and flowering season, which is essential for really effective perennial landscaping. Landscaping relies on plants being situated in their ideal growing position, as well as ensuring that the plants are allowed to spread. Colour co-ordination in your landscaping plan is important too. Just a hint of discord will really put out the balance of your planting scheme.

The following Perennial plants are ideal for the back of the border, or for individual or group planting and these lovely tall plants can really bring height and structure to your perennial landscaping:

Asters- Some varieties grow to around 36" tall, spread 24".

Flowers- September to October.

Colours- red, pink, purple, white, lavender,blue.

Achillea- Yarrow " Coronation Gold" 30-36" tall, spread 18-24".

Flowers- June to July.

Colour- golden yellow.

Babtisia australis- 30-36" tall, spread 36-48".

Flowers- early to late June.

Colour- light purple, with large seed pods.

Boltonia asteroides- "Snow Bank" 36-60" tall, spread 24-36".

Flowers- September to October.

Colour- light purple.

Campanula - "Blue and White Clips" 72- 96" tall, spread 12-18".

Flowers- from June to July.

Colour- blue or white.

Campanula persicifolia- "Peach Leaf Bell Flower" 30-40" tall, spread 12-18".

Flowers- early June.

Colour- White or blue.

Dicentra spectablis- "Bleeding Heart"- 30-36" tall, spread 18-24".

Flowers- May.

Colours- red, white.

Echinacea purpurea- "Purple Cone Flower Bright Star" 36-48" tall, spread 18-24".

Flowers- July.

Colour- purple.

Eupatorium maculatum- "Gateway" 36-60" tall, spread 24-30".

Flowers- end of summer to early fall.

Colours- mauve, rose.

Filipendula rubra venusta- "Queen of the Prairie" 36-60" tall, spread 24".

Flowers- early to mid summer.

Colour- Rosy pink.

Heliopsis scabra- "False Sunflower Summer Sun" 36-60" tall, spread 24-30".

Flowers- July to September.

Colour- yellow.

Hemerocallis hybrids- "Day lily" 12-40" tall, spread 18-24".

Flowers- June to August.

Colours- red, yellow, orange, cream.

Iris siberica- "Siberian Iris" 36" tall, spread 18-24".

Flowers- May to June.

Colours- blue, white, purple.

Lilium hybrid- "Asiatic Lily" 30-40" tall, spread 12".

Flowers- June-July.

Colours- red, white, pink, orange, yellow.

Malva fastigiata- "Malva" 36" tall, spread 24"

Flowers- June to end of summer

Colour- pink.

Perovaskia atriplicifolia- "Russian Sage" 36-48" tall, spread 24-36".

Flowers- July to October.

Colour- lavender blue.

Rudbeckia nitida- "Herbstonne"- 72"+ tall, spread 36-48".

Flowers- August.

Colour- yellow.

Rudbeckia subtomentosa- "Sweet Cone Flower"- 36-48" tall, spread 24-36".

Flowers- August to September.

Colour- yellow.

There are of course many other perennial plants which can be used for landscaping, including many different varieties of grasses. However these are so varied, that they really merit an article all to themselves. If you plant only a few of the plants mentioned here, you will be well on the way to having achieved some really stunning perennial landscaping.

Perennial landscaping benefits greatly from easy to grow plants. Here we will look at some of those which can be used with great effect, for landscaping, with details such as their height and flowering season, which is essential for really effective perennial landscaping. Landscaping relies on plants being situated in their ideal growing position, as well as ensuring that the plants are allowed to spread. Colour co-ordination in your landscaping plan is important too. Just a hint of discord will really put out the balance of your planting scheme.

The following Perennial plants are ideal for the back of the border, or for individual or group planting and these lovely tall plants can really bring height and structure to your perennial landscaping:

Asters- Some varieties grow to around 36" tall, spread 24".

Flowers- September to October.

Colours- red, pink, purple, white, lavender,blue.

Achillea- Yarrow " Coronation Gold" 30-36" tall, spread 18-24".

Flowers- June to July.

Colour- golden yellow.

Babtisia australis- 30-36" tall, spread 36-48".

Flowers- early to late June.

Colour- light purple, with large seed pods.

Boltonia asteroides- "Snow Bank" 36-60" tall, spread 24-36".

Flowers- September to October.

Colour- light purple.

Campanula - "Blue and White Clips" 72- 96" tall, spread 12-18".

Flowers- from June to July.

Colour- blue or white.

Campanula persicifolia- "Peach Leaf Bell Flower" 30-40" tall, spread 12-18".

Flowers- early June.

Colour- White or blue.

Dicentra spectablis- "Bleeding Heart"- 30-36" tall, spread 18-24".

Flowers- May.

Colours- red, white.

Echinacea purpurea- "Purple Cone Flower Bright Star" 36-48" tall, spread 18-24".

Flowers- July.

Colour- purple.

Eupatorium maculatum- "Gateway" 36-60" tall, spread 24-30".

Flowers- end of summer to early fall.

Colours- mauve, rose.

Filipendula rubra venusta- "Queen of the Prairie" 36-60" tall, spread 24".

Flowers- early to mid summer.

Colour- Rosy pink.

Heliopsis scabra- "False Sunflower Summer Sun" 36-60" tall, spread 24-30".

Flowers- July to September.

Colour- yellow.

Hemerocallis hybrids- "Day lily" 12-40" tall, spread 18-24".

Flowers- June to August.

Colours- red, yellow, orange, cream.

Iris siberica- "Siberian Iris" 36" tall, spread 18-24".

Flowers- May to June.

Colours- blue, white, purple.

Lilium hybrid- "Asiatic Lily" 30-40" tall, spread 12".

Flowers- June-July.

Colours- red, white, pink, orange, yellow.

Malva fastigiata- "Malva" 36" tall, spread 24"

Flowers- June to end of summer

Colour- pink.

Perovaskia atriplicifolia- "Russian Sage" 36-48" tall, spread 24-36".

Flowers- July to October.

Colour- lavender blue.

Rudbeckia nitida- "Herbstonne"- 72"+ tall, spread 36-48".

Flowers- August.

Colour- yellow.

Rudbeckia subtomentosa- "Sweet Cone Flower"- 36-48" tall, spread 24-36".

Flowers- August to September.

Colour- yellow.

There are of course many other perennial plants which can be used for landscaping, including many different varieties of grasses. However these are so varied, that they really merit an article all to themselves. If you plant only a few of the plants mentioned here, you will be well on the way to having achieved some really stunning perennial landscaping.

Perennial landscaping benefits greatly from easy to grow plants. Here we will look at some of those which can be used with great effect, for landscaping, with details such as their height and flowering season, which is essential for really effective perennial landscaping. Landscaping relies on plants being situated in their ideal growing position, as well as ensuring that the plants are allowed to spread. Colour co-ordination in your landscaping plan is important too. Just a hint of discord will really put out the balance of your planting scheme.

The following Perennial plants are ideal for the back of the border, or for individual or group planting and these lovely tall plants can really bring height and structure to your perennial landscaping:

Asters- Some varieties grow to around 36" tall, spread 24".

Flowers- September to October.

Colours- red, pink, purple, white, lavender,blue.

Achillea- Yarrow " Coronation Gold" 30-36" tall, spread 18-24".

Flowers- June to July.

Colour- golden yellow.

Babtisia australis- 30-36" tall, spread 36-48".

Flowers- early to late June.

Colour- light purple, with large seed pods.

Boltonia asteroides- "Snow Bank" 36-60" tall, spread 24-36".

Flowers- September to October.

Colour- light purple.

Campanula - "Blue and White Clips" 72- 96" tall, spread 12-18".

Flowers- from June to July.

Colour- blue or white.

Campanula persicifolia- "Peach Leaf Bell Flower" 30-40" tall, spread 12-18".

Flowers- early June.

Colour- White or blue.

Dicentra spectablis- "Bleeding Heart"- 30-36" tall, spread 18-24".

Flowers- May.

Colours- red, white.

Echinacea purpurea- "Purple Cone Flower Bright Star" 36-48" tall, spread 18-24".

Flowers- July.

Colour- purple.

Eupatorium maculatum- "Gateway" 36-60" tall, spread 24-30".

Flowers- end of summer to early fall.

Colours- mauve, rose.

Filipendula rubra venusta- "Queen of the Prairie" 36-60" tall, spread 24".

Flowers- early to mid summer.

Colour- Rosy pink.

Heliopsis scabra- "False Sunflower Summer Sun" 36-60" tall, spread 24-30".

Flowers- July to September.

Colour- yellow.

Hemerocallis hybrids- "Day lily" 12-40" tall, spread 18-24".

Flowers- June to August.

Colours- red, yellow, orange, cream.

Iris siberica- "Siberian Iris" 36" tall, spread 18-24".

Flowers- May to June.

Colours- blue, white, purple.

Lilium hybrid- "Asiatic Lily" 30-40" tall, spread 12".

Flowers- June-July.

Colours- red, white, pink, orange, yellow.

Malva fastigiata- "Malva" 36" tall, spread 24"

Flowers- June to end of summer

Colour- pink.

Perovaskia atriplicifolia- "Russian Sage" 36-48" tall, spread 24-36".

Flowers- July to October.

Colour- lavender blue.

Rudbeckia nitida- "Herbstonne"- 72"+ tall, spread 36-48".

Flowers- August.

Colour- yellow.

Rudbeckia subtomentosa- "Sweet Cone Flower"- 36-48" tall, spread 24-36".

Flowers- August to September.

Colour- yellow.

There are of course many other perennial plants which can be used for landscaping, including many different varieties of grasses. However these are so varied, that they really merit an article all to themselves. If you plant only a few of the plants mentioned here, you will be well on the way to having achieved some really stunning perennial landscaping.

Perennial plants are very important when planning a garden which stays beautiful year after year, with the minimum amount of effort. However there are a few points which need to be taken into consideration.

Firstly, you need to take into consideration, the area in which you live. Perennial plants which flourish in Florida, may not be able to survive in New York, where the winters are so much harder. It is vital, if you are planting perennial plants, that you find out your plant zone, and choose your plants accordingly.

Decide on the type of garden you want, this is essential for low maintenance. This will enable you to build your ultimate garden, right from the beginning. Perhaps you want your garden to have a particular colour or theme, by deciding at the start, you will be able to choose exactly the right perennial plants, without costly mistakes.

Make sure the plants you choose are low maintenance, although perennial plants return year after year, some need far more maintenance than others. Choose perennial plants which need little pruning and are drought resistant. Always remember however, that you should choose your plants for their beauty, not just their hardiness. A low maintenance garden doesn't have to be boring, it should be stunning.

Once you have decided on the type of garden you want and which perennial plants you would like, there are a few more thing to consider for your low maintenance garden. For example, what is the height of the plants you have chosen. Always make sure that the highest plants are behind the lowest perennial plants. This will ensure that all your perennial plants get good light and you won't need to prune plants which have outgrown their neighbours.

It is important too that you plant perennial plants which require lots of water together, then you will only need to water a small area, rather than the whole garden. Be sure to add plenty of organic matter to the soil before you plant your perennials, this will not only give your perennial plants a good start, but will mean that you don't have to add further fertilizer.

Water your newly planted perennial plants in well, and then sit back and wait for your beautiful low maintenance garden, full of perennial plants to become more beautiful as time moves on.

If you have been thinking about making a start in hobby foundry work in your home workshop, you may be forgiven for thinking that the tools and equipment are going to cost you an arm and a leg, this need not be. Sure, you could trot off to the downtown industrial tools supplier and take home an arm full of expensive tools.

But if you take a good look at some of the tools, you'll discover that the design principles and fabrication could well be undertaken in the home workshop if you have metal fabrication skills and a reasonable amount of basic metal working equipment.

Take for instance "crucible lifting tongs", once you understand how these tools operate; you could quite easily make a set or two over a weekend. The basic design action operates on the "scissor principle" but they don't cut anything, they are designed to "clamp securely" onto the crucible to lift it out of the furnace when the metal has melted. Great caution needs to be taken while carrying out this operation, as one slip due to faulty or badly designed tongs, and you could have a disaster on your hands.

The best way to design and build a set of tongs is to copy a well made set, or to follow directions set out in a textbook or ebook downloaded from the net, we'll give you some links a little further on in this article.

Some of the most frequently used basic tools you'll need in the hobby foundry are; Bench ramming moulders tool - Tube sprue cutter - turned wood sprues - slick & oval spoon - hand riddle or sand sieve - draw pins, screws & hooks - rapping bar and spike - gate cutter - strike off bar - sand carving tools (made from old hacksaw blades). The tools mentioned above seem to be the ones that will be most used in your hobby foundry... and all of them can be home made if you have metal & wood working skills, it will take time and effort to make the tools required but they wont cost you a red cent if you make them from scrap materials, and if you are like most hobbyists you will know where to "scrounge stuff".

You may have to experiment with different ideas before you arrive at the most satisfactory design, but you will learn a great deal about why things have to be made in certain ways.

Do you own a wood lathe? Even a most basic machine will suffice in the home workshop, you could even make your own if you were keen enough,I guarrantee there are tens of thousands of home made wood lathes sitting in hobby workshops the world over. A wood lathe will repay itself many times over when you start to make patterns for your hobby foundry.

Your bench-ramming tool can be quickly turned to shape on your wood lathe, in fact, while you're at it, make two or three of them in different shapes & sizes, they will all come in handy when ramming and moulding patterns of differing sizes, you could get away with a single tool, but you wont regret making extra tools.

After a pattern has been completely rammed in a sand mould, and before the metal is poured, the pattern has to be removed without disturbing any of the surrounding sand. Draw pins and spikes are used to remove timber patterns from sand moulds.

Simple draw pins can easily be fabricated from long slender wood screws, particleboard screws are ideal. The easiest way to convert woodscrews into draw pins is to braze-weld a short length of 1/4" dia mild steel rod onto the head of the screw...that is all you need to do... make a set of them with different gauge screws as well long and short ones and you should have the field covered as far as lifting pins or draw spikes go... simple isn't it.

Blunt hacksaw blades are usually thrown in the bin, from now on you should save them, as many useful little hobby foundry tools can be made from old saw blades, quite often small sand carving tools can be quickly made by grinding and shaping using a normal bench grinder.

By being resourceful and thinking how you can use scrap materials, you should see now that there is absolutely no need to spend large amounts of money to get the tools and things you need for your hobby. If you are not sure about your own building & fabricating abilities then you should always ask advice.

To produce cavities within a metal casting; as required for liquid cooling in engine blocks and cylinder heads. Special negative forms (core boxes) are used to produce sand cores. Cores can be made up from oil bonded sand, often a basic oil such as linseed oil can be used to make effective sand cores. Once made in the negative shaped core box the sand core is baked in an oven until it is cured.

Cores are inserted into the mould box after removal of the pattern from the sand. Whenever possible, foundry pattern are designed and made to avoid the use of cores, reducing the use of cores will reduce the mould set-up time and thus help to reduce labour costs in the foundry.

With a completed sand mould at the appropriate moisture content, the box containing the sand mould is then positioned ready to fill with molten metal; i.e. ferrous iron (cast iron) steel, or none ferrous bronze, brass, or aluminium alloy.

After filling with molten metal the box is set aside until the metal is sufficiently cool to enable the removal of the hot casting from the sand mould. A rough casting is produced that, in the case of iron or steel, may still be glowing red.

When casting with metals like cast iron or lead, which are significantly heavier than the moulding sand, the flasks, called the cope & drag is covered with a heavy plate to prevent a problem known as mould floatation. Floating the mould occurs when the pressure of the metal pushes the sand above the mould cavity out of shape, causing the casting to fail. Sometimes mould box clips or flip locks are used to lock the boxes together to prevent loss of metal due to the drag mould loating.

After casting, the inner cores are broken up by rods or shot and removed from the casting. The metal from the sprue and risers is removed from the rough casting.Various heat treatments may be applied to relieve stresses from the initial cooling and to add hardness; in the case of steel or cast iron, by quenching in water or oil.

The casting may be further strengthened by surface compression treatment such as shot peening, which adds resistance to tensile cracking and smoothes the rough surface, cast iron engine conrods are treated in this manner.

The above methods and techniques can be applied to the hobby foundry, as well as the commercial set up, you have to think about what you are doing and the application of internal sand cores to your project.

Green sand is one of the oldest foundry moulding mediums known to the industry, its use in the foundry can be traced back to the early times. But do you know how to get the best from it.

While it's use in commercial foundry operations has diminished somewhat, green sand still has its place in the hobby foundry. Green sand can be made up using quite basic materials, and is still being used to produce sound quality aluminium, bronze, and grey iron castings in many hobby foundries scattered across the globe.

Green sand is also ecologically friendly in that it can be recycled & reused almost indefinitely, before being discarded in favour of a newly mulled batch.

When green sand was the preferred commercial moulding material, special machines were used to reprocess the sand to remove foreign objects and to break down the dry sand lumps and recondition the sand again for the moulding shop.

Because green sand is reconditioned or re-tempered by the addition of water, it requires quite a bit of processing work to make it suitable again for moulding work.

Unfortunately, the hobby foundry worker does not have the luxury of automatic processing machines, so the reconditioning task for the hobby foundry worker is reduced to a laborious manual process, which can soon become tiresome if a large quantity of sand has to be processed.

When we speak about reprocessing green sand, we are not talking about the mulling or milling of a new batch of green sand, which is quite a different issue.

To recondition green sand it is normally fed into a sand slinger to break the lumps and clods, which form naturally in the green sand mould during solidification of the metal castings, much of the moisture content of the sand is also driven off during this stage.

One option for the hobby worker to recondition and retemper green sand is to use the slow manual hand sieving method whereby the operator manually processes the sand through a wire riddle in order to break up the lumpy sand, then the retempering can be done by slowly adding water and cutting, turning and dumping the sand with a shovel.

Yes, it is hard work and a slow process, and one in which most hobby workers will rapidly lose interest.

If you want to use green sand in the hobby foundry, but don't want to retemper the sand by this hard labour manual system, then, there is another way. The quickest, easiest way to retemper small batches of green sand such as the hobby worker would require, is to use a motorised gyratory riddle.

The riddle is capable of processing a large quantity of sand in 10 to 15 minutes, which includes the fluffing and the retempering process, it is virtually a simultaneous three way process.

The quality of green sand produced through this method is second to none, and the motorised gyratory riddle greatly reduces the back breaking labour to virtually zero. Anyone with general metal fabricating skills could easily build a riddle, the material costs are not expensive and are readily available.

The main requirements are: A small electric motor, a wire sieve, some square tubing to build the frame, plus the instructions to build an efficient machine.

Solid plaster and cement rendering workers in the building trade could also use this type of machine to prepare mortars and wall-finishing materials applied by the baggin

Minerals containing aluminium are very difficult to decompose. In 1825, a Danish scientist H.C.Oersted discovered that metallic potassium could be used to chemically reduce aluminium from one of its compounds. The cost of aluminium in the very early days was around 250.00 English pounds per kilo to produce, much more than gold.

Even Napoleon was reported to have been privileged to use Aluminium knives and forks when eating. French nobility had to be content with silver or gold tableware?

Metallurgists, Hall (America) & Heroult, (France) discovered the process for extracting aluminium from the ore of bauxite in the year of 1886, but the metal remained an expensive commodity until the beginning of the 1900s.

The first & second world wars, saw a huge demand for this strong, light & versatile metal, particularly in the manufacture of aircraft. Modern technology has pushed the annual production of Al second only to iron in world production terms.

The ore of aluminium is called bauxite, it contains aluminium oxide Al203. Bauxite ore itself cannot be reduced to metal by heating it with coke as with cast iron, for the simple reason that Al atoms are too firmly combined with oxygen atoms to be detached by carbon.

An electrolytic process is used to decompose the bauxite and release the Aluminium, which consumes about 91 mega joules of electricity to produce I. Kg of Al metal, so large amounts of cheap electrical power must be available to the smelters.

Most of the world's aluminium was produced in the USA, Canada, & Norway. However, Australia also has vast deposits of bauxite, and has large Smelters situated near the major power producers in the country.

This abundance of aluminium supply has had the effect of producing a readily available stockpile of scrap aluminium, where it is not difficult for the hobby foundry worker to easily break the metal down to manageable sizes, which can then be melted in small hobby gas or electric furnaces.

Crude pig iron is purified or converted to steel by blowing oxygen through it, Which burns out the impurities, this is not possible with aluminium as the metal would simply burn away, and leave you with useless impurities.

A chemical process is first used to purify the bauxite, then the pure aluminium oxide is decomposed by electrolysis. Aluminium oxide has a very high melting point, it is mixed with another aluminium mineral called cryolite, to form an electrolyte, which will melt at a low temperature.

Next time you are breaking down a piece of scrap aluminium to place into your crucible to melt, spare a thought for the journey it has travelled before you acquired it!

Today's technology enables the semi skilled home hobby foundry worker to produce low cost Aluminium castings for all kinds of purposes, but there are things that you must learn about, and equipment you must acquire or build before the metal casting journey can begin. To begin to explore and understand what this intriguing metal craft is all about, you are invited to visit our hobby foundry web site.

Green sand is one of the oldest foundry moulding mediums known to the industry, its use in the foundry can be traced back to the early times. But do you know how to get the best from it.

While it's use in commercial foundry operations has diminished somewhat, green sand still has its place in the hobby foundry. Green sand can be made up using quite basic materials, and is still being used to produce sound quality aluminium, bronze, and grey iron castings in many hobby foundries scattered across the globe.

Green sand is also ecologically friendly in that it can be recycled & reused almost indefinitely, before being discarded in favour of a newly mulled batch.

When green sand was the preferred commercial moulding material, special machines were used to reprocess the sand to remove foreign objects and to break down the dry sand lumps and recondition the sand again for the moulding shop.

Because green sand is reconditioned or re-tempered by the addition of water, it requires quite a bit of processing work to make it suitable again for moulding work.

Unfortunately, the hobby foundry worker does not have the luxury of automatic processing machines, so the reconditioning task for the hobby foundry worker is reduced to a laborious manual process, which can soon become tiresome if a large quantity of sand has to be processed.

When we speak about reprocessing green sand, we are not talking about the mulling or milling of a new batch of green sand, which is quite a different issue.

To recondition green sand it is normally fed into a sand slinger to break the lumps and clods, which form naturally in the green sand mould during solidification of the metal castings, much of the moisture content of the sand is also driven off during this stage.

One option for the hobby worker to recondition and retemper green sand is to use the slow manual hand sieving method whereby the operator manually processes the sand through a wire riddle in order to break up the lumpy sand, then the retempering can be done by slowly adding water and cutting, turning and dumping the sand with a shovel.

Yes, it is hard work and a slow process, and one in which most hobby workers will rapidly lose interest.

If you want to use green sand in the hobby foundry, but don't want to retemper the sand by this hard labour manual system, then, there is another way. The quickest, easiest way to retemper small batches of green sand such as the hobby worker would require, is to use a motorised gyratory riddle.

The riddle is capable of processing a large quantity of sand in 10 to 15 minutes, which includes the fluffing and the retempering process, it is virtually a simultaneous three way process.

The quality of green sand produced through this method is second to none, and the motorised gyratory riddle greatly reduces the back breaking labour to virtually zero. Anyone with general metal fabricating skills could easily build a riddle, the material costs are not expensive and are readily available.

The main requirements are: A small electric motor, a wire sieve, some square tubing to build the frame, plus the instructions to build an efficient machine.

Solid plaster and cement rendering workers in the building trade could also use this type of machine to prepare mortars and wall-finishing materials applied by the baggin

Furnace burners potentially create more than enough problems for the hobby metal casting worker, it is not unusual to read about people who are attempting to build a furnace, only to be confronted with problems and frustration with a complex burner? It is quite simple to construct a crucible furnace, but the stumbling block seems to be: "The burner". Why?

Problems seem to manifest themselves because:

For some reason, people choose to fabricate complex burners from detailed drawings without the skills, tooling and machining facilities in which the original designer employed during the design & building process.

With the necessary workshop skills coupled with a reasonable selection of equipment & tools, will have a marked effect on how well you, as a hobby foundry worker, will be able to construct the equipment required for the successful melting of metal.

There are no short cuts when it comes to building equipment for your hobby foundry, to cobble something together in a rough fashion is only asking for trouble in the future, it is well to heed the old trade school teacher quote: "If a job is worth doing, you might as well do it properly in the first place" He is right, you know.

You can learn how to build an effective simple furnace burner, which is well documented in the hobby foundry ebook "Metal Casting Made Easy" available at our web site. But to explain everything in detail here would take up far too much time & space.

Following is a simplified description:

The burner consists of a long plain black mild steel pipe. The burner end nozzle consists of an inverted cone. There is a mid section where a venturi is installed; the gas jet is located near the venturi.

The simple brass jet protrudes into the forced air stream, which travels through the burner tube. The gas jet orifice is quite large and operates under low pressure; the air delivered by the blower to the burner tube is low pressure, but moves at a high volume.

The burner design is simple, yet effective, but there are some components incorporated in the design that only require basic lathe turning skills. But general workshop knowledge is sufficient to build this item. There's no rocket science involved.

The blower consists of a second hand household vacuum cleaner (the type that has a second outlet for the hose connection that blows). The vac also has an electronic vari motor speed control, which enables a regulated low-volume airflow to be delivered during the burner start up phase.

This feature is MOST important during the furnace start up.

Does this burner work? You bet it does, the burner is capable of melting a 5 Kg (11lbs) charge of Aluminium from a cold start in less than 40 minutes.

The gas supply is provided from a Liquid Petroleum (LP) cylinder (Propane in the states) It is essential that the gas supply be controlled by an adjustable industrial diaphragm gas regulator gauge suitable for LP gas, there is no other SAFE way to regulate & deliver fuel gas to a furnace burner. A ball valve should be installed in line as an emergency shut off valve.

There's no reason to build & operate complex burners that require special size jets, and shrouds, which must be operated at a certain gas/air pressure? There is nothing more frustrating than an apparatus that won't operate as it should; why spend half the day mucking around with something that is an absolute pain to use, when you should be enjoying your metal casting experience!