Indigenius Aluminum Casting in Nigeria

introduction

general overview of the crafts in Nigeria

In a monolithic society as Nigeria, arts and crafts played an important social, economic, as well as utilitarian role which has helped in the developmental needs of the nation. The crafts industry was one of the major commercials ventures in Nigeria prior to the era of crude-oil. It is worthy of note that Nigerian crafts have continued to grow to perfection in techniques, finishing and packaging.

The indigenous metal casting for the production of household utensils such as metal pots, spoons and bowls of different sizes are increasingly becoming popular in Nigeria. The production method involves the use of a conventional sand casting procedure in which two-part flasks with a split drag are employed in the molding. This metal casting is operated at the cottage level and most of the people involved have qualifications below junior secondary school level with no metallurgical or any other engineering background. This small business has good prospects and can be a basis for the development of indigenous technological capability building in metal casting in Nigeria.

This paper therefore is intended to show the method and the processes of Aluminum pot casting in Saki, Oyo state. According to the geographical map of Nigeria, Saki is a small town located in the northern part of Oyo state. The neighboring town includes: ago-are, ighoho, ipapo, tede, etc. other crafts being practice by the people of Saki are pottery, cloth-weaving, etc.

Historical Background

Casting generally is a process of producing solid objects by pouring molten material into a shaped mold and allowing it to cool. It is used to shape the metals and alloys. The casting of metals has been practiced for more than 6,000 years, using first copper and bronze, then iron, and now alloys of zinc and other metals. The traditional method of casting metal is the sand casting. Using a model of the object to be produced, a hollow mold is made in a damp sand and clay mix. Molten metal is then poured into the mold, taking its shape when it cools and solidifies. The sand mold is broken to release the casting.

Casting aluminum pot (known as the ikoko irin by the Yoruba’s) from the book of history was an imported craft. It was said to have been started by one Mr. Tiyamiyu Aremu in 1968 that learnt the craft techniques from cote de voire. According to my source , it was said that he later went and settle in Oyo not until the people who have also learnt the same craft techniques in other places like Ghana where driven home by Busier, Saki now became the abode of this deportees, all this happened in Ghana in 1969. In 1970, a society of iron importers was launched officially and it flourished till date. I noticed this during my first visit to Saki that the houses owned by the indigenes of Saki are always used for this craft. And moreover almost all the children living in this community are into this craft alongside with their education

materials and tools

MATERIALS

Over the time, there have been developments of the materials and tools used for this craft. The major Materials used are the Aluminum scraps. Aluminum which is a lightweight, silvery metal. The atomic weight of aluminum is 26.9815; the element melts at 660°C (1220°F), boils at 2519°C (4566°F), and has a specific gravity of 2.7. Aluminum is a strongly electropositive metal and extremely reactive. In contact with air, aluminum rapidly becomes covered with a tough, transparent layer of aluminum oxide that resists further corrosive action. For this reason, materials made of aluminum do not tarnish or rust. The metal reduces many other metallic compounds to their base metals. For example, when thermite (a mixture of powdered iron oxide and aluminum) is heated, the aluminum rapidly removes the oxygen from the iron; the heat of the reaction is sufficient to melt the iron. Aluminum is said to be non-toxic and does not release any odour or taint products with which it is in contact. Aluminum which is also the most costly component and pieces of cast iron which are majorly gotten from local sources such as machine spare parts. Aluminum metal cannot be melted in isolation because the end product will be brittle and will withstand external pressure. Some cast iron is added as a flux to strengthen the body. Ababio(1990:p427) described aluminum as a good conductor of heat, it is very light and cheap; therefore it is prescribed as the best metal that can be used for cooking utensils.

Research shows that aluminum is the worlds' most abundant metal and the third most common element comprising eight percent of the earth's crust. And the versatility of aluminum makes it most widely used metal after steel. The recyclables of aluminum is unparalleled. There is no difference between virgin and recycled aluminum in terms of quality as when recycled there is no degradation in properties when compared to virgin one. And recycle aluminum only uses 5 percent of the input energy required to produce virgin material.

The basically make use of the used ones (aluminum scraps), condemned engines of vehicles. Images of these scraps are highlighted below

Another common material that is very important include the deposit of sand used in forming the mould. The preferred sand that is general used by this people is the loamy sand. Loamy sand is a mixture of sand and clay particles with high proportion of organic matter

fine ash used in mould finishing, this material is also commonly known as the soot which is a powdery form of carbon that is being derived from the burning of wood, coal, or oil, which rises up in fine particles with the flames and the smoke.

carbonated manganese oxide is derived from used dry cells which is used in the removal of impurities from the alloy.

charcoal which serves as the energy source for the melting of metals on the furnace and many other uses.

Another material that is needed is the patterns which could either be ( patterns of aliminium pot and the covers). A pattern comprises of a prototype that has been sliced into two halves.

Patterns of the Aluminium pot

• These pots are in sizes. We have sizes ranging from (1-60), i.e. 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 20, 30, 40, 50, and 60

Shown above is a pattern of a size 40 aluminium pot

• There are also the E-pot which can be classified into the E2, E3, E4, E5, E6, E8, E10, E12, E20
• Part of the pattern of pot use is the BASIA (which could either be the small or the big)
• There is also the flat 12 pot
• There is also the AGBADA GARI (which could either be the small or the big size)

Patterns of the covers

• Its process involved in the production is the same in the production of the pot itself.

TOOLS

The Production of this craft is mainly based on the use of simple tools, scraps and some crude implements.

The following are the common tools used in the production of various cast aluminum products:

Ø Wooden racks – this is a wooden framework usually rectangular in shape, used as supportive guides to the moulds. They exist in different sizes depending on the size of the pot that is intended for. This is a wooden piece that is constructed in a bench-like form to suit the piece that is meant to be produced depending on the size

Ø Club and Sticks – they are used in the preparation of the sand mould.

Ø Shovel and Hoe – they are used for sand filling, loosening lumps of sand after casting and packing loosed materials.

Ø Scale balance – it is used to measure the weight of the raw materials and most times, the finished products.

Ø Metal rings – the metal rings are long strip of metal used to hold the cast iron pot used as mould in sand filling. This is usually applicable to the rounded bottom pots.

Ø Crucible – this is a heating container used in the melting of the metals used in the casting.

Ø Tong – this tool which is about 1.5m in length is used for the molten metal transfer and pouring of the molten metal into the mould. In a nutshell, it is used to carry the molten metal.

Ø Iron wire – it is used for holding and tightening racks together for sand mould.

Ø Spoons – they are used for smoothening and finishing the internal and external walls of the sand model. It is also used in collecting various phases in mould making and casting.

Ø Small pipe – the small iron pipe is used in making a circular opening where the molten metal is poured into the mould.

Ø Air wheel/fan/blower– this is the air supplier or blower that supplies the furnace air of combustion.

Ø Hammer - one of their hand tool consisting of a shaft with a metal head at right angles to it, used for forging and beating metal. They commonly make use of the small hammer.

Ø BALL SPANNER - a wrench with a hook or pin at one or both ends of the engaging corresponding notches or holes on the object to be turned. This spanner varies in diameter of the notches.

Ø Tester - they use it to tests if their machines (fan/blower, generator) or any of their devices is working properly. It helps to no if there is a low or high voltage.

Ø Melting furnace – this is described as an enclosure place where smelting is being carried out. It is basically made of clay. It is known to the Yoruba’s as the ‘OJU-ARO’.

Ø Generator - this is used when there is no light to power on the blower during smelting.

Ø Labels and brands - are used for writing names and logos on their pots.

Ø Belt - are used to tighten the patterns (the two halved prototype) together to get a perfect molding.

Ø Flange - are used for creating a demarcation or boundary between the pattern to derive or yield a separate mode after demolding.

Ø Empty cans - Are basically used for the carrying the smelted aluminum to the place where they are being poured.

Other tools includes the finishing tools

Ø hacksaw

Ø CHISEL

Ø iron Brush

Ø Paint

Ø files

Ø Pliers

PROCESSES OR TECHNIQUES INVOLVED

The processes involved in the production of aluminium pot are: The molding and the casting

MOLDING

The following are the processes involved in MOLDING. This could be grouped into the interior and the exterior aspects.

INTERIOR ASPECTS

This interior processes helps the producer to create the mold of the interior part of the pot. The procedures to this process are highlighted below:

Make available the prototype of the pot to be used depending on the size of pot given to the producers to produce by the customer or at times the size of pot the producers’ wishes to produce for sale. As the one shown below

The next step is to lay the bed. This is done by spreading the sand on an available space on the ground that is convenient for the piece to be done. This step is made with the use of the hoe, the spade, planks to make the bed very smooth and rigid (i.e. well compressed). An image of this is shown below

Laying of the platform

At this stage, the method of using the belt comes in. the belt could be made of metal or leather, whichever suits the producer or manufacturer. The producer uses the belt to tie the two half patterns of pot. After which the sand must be poured inside and compressed in such a way that the sand inside would be as hard as a stone. An image of this procedure is displayed below

Shown above is a worker compressing and exerting pressure on the sand to make them coagulate and form together, after packing in little sand, he pour in another sand and then compresses them again. All this is done because he wants to derive a uniform thickness in mold he is producing. Image of these procedures are displayed below

A worker pouring in more sand a worker compressing the sand and myself

pouring in more Sand to assist him

When the pot is now full with sand and well compressed to make it hard, then the use of a flat wood is introduced to level the sand. An instance are displayed below

When the sand was full during the leveling of the sand to yield a flat surface/platform

The end result of the compressing procedure

After this stage, he then scoops the middle area a little bit for easy-demolding.

The next stage is to carry the piece and invert it (that is turned it upside down on the already prepared bed of sand which the Yoruba usually call the ADA). As displayed below

note:

All this due process that have been mentioned above are necessary/important for the purpose of creating a mold for the interior part of the pot

EXTERIOR ASPECT

This process is very technical, all it requires the technical expertise of the producer. The reason being that it helps the producer to create the exterior part without undergoing any sort of problem. It must also be noted that the outer mold requires two or more layers of the wooden rack depending on the nature of the cast or depending on the size of the pot to be made. The procedures are highlighted above

The first step that comes after the interior aspect is the use of a flange at the intersection between the patterns as shown below

After which the producer is required to place a whole wooden rack which must be proportionate to the size of the model pot around the piece. This will help to create the exterior part. After which they must be tightened firmly with a piece of a rope. An instance is displayed above

After the above mentioned step, sand is being introduced and poured to fill up the first layer of the wooden rack and must be compressed thoroughly to derive the specific shape (circular in shape). In this case, the first rack is for the lower section while the successive racks serve as the upper part. As the rack is filled with sand, it is also compressed with the club and leveled up with a flat stick.

The images are displayed below

After filling the rack, the second rack which exists as a whole piece is placed on top directly on the rim of the first. This layer is filled to cover up the mould. The compacted sand is usually mounted on it like a heap-like pattern. It must be noted that this is at the peak of the heap of the sand that is the part which link directly to the centre of the mould. A tunnel shaped opening is created with a small iron pipe and spoon is been used to create a hole for the pipe. This indicates the point where the molten metal is poured into the mould grains of dry sand usually added in between the layers to create partition.

After which another set of wooden rack is being placed on the first batch in order to create the circular top of the aluminum pot. After which it must be leveled and well compressed. Looking at the processes from the beginning, a novice would be wondering how everything would come out successful.

When the mould blocks are completed, the next thing to do is to withdraw the racks aside to expose the pot model and allow the pot model to be disengaged from the inner block of the sand (core). After the detachment, the inner mould is revealed. Then the inner walls of the mould block are then burnished and smoothen with a flat spoon after investing a layer of fine ash on them. Alongside, other necessary touches are added to get desired result. At this phase, labels and brands can be of an added impression on the internal walls. This will actually emerge as a relief on the body of the ware. The mould of the cover is done in the same way, but it is racked once.

When the mould is made to perfect, its component are restored back and set in the former positions. At this stage, casting can be carried out. It should also be noted that the thickness of the pot will be determined by the cast iron used as the pattern.

CASTING

While the sand mould is been prepared and ready or doing the processes involved, the metals that are meant to be used for casting are being heated in a crucible on the furnace. When the melting is being judged ready, impurities in the mixture of the molten metals are removed with a long and slim metal plate. The metal molten metal is an alloy of aluminum and draughts or scrap of metals. The molten metal is judged ready when the carbonated manganese oxide is being added and all the impurities in the molten alloy metal, there will be a change in the color of the metal to a yellowish-orange when viewed under no light influence.

The images shown above are part of the assistance that was rendered by me to the potters during those moments I spent with them

After all the moulds have been made and the molten metal is ready, it is then carried with the tong and poured through the hole created on the moulds and allowed to cool probably by adding or sprinkling of water heavily on them. The moulds are broken down to reveal the cast ware and the content is emptied by hitting against the ground gently while holding the protrusion at the bottom of pot with the tong. The same process is also repeated for the cover of the pot.

After the cleaning processes have been done correctly, the pots are been collected and taken to where it will be finished. All the protrusion on the body of the pot will be cut-off and are filed smoothly and all defects will be made detected and corrected. After which they are being taken/allocated to different market places for sale

The size 40 pot The cover

The end product of the craft after finishing

The collections of the finished products that are being kept in their store after production

THE FUTURE PROSPECTS

Presently, the practice of this craft is restricted to men nevertheless it creates room for new apprentices to be easily recruited thus ensuring its continuity.

The migration of craftsmen to other towns gives rise to the diffusion of this craft and culture in Nigeria.

With the trends of things, the craft if well promoted and developed through technological ideas, will proffer solution to our economic standard and consequently fit for foreign exchange. In recent times, the government policies made to guide against the use of foreign products, I believe this policy has highly favored the marketability of this local cast aluminum products for quite some times now (to some extent).

In summary, this small business has good prospects and can be a basis for the development of indigenous technological capability building in metal casting in Nigeria if given proper/adequate attention/approach.

CHALLENGES AND PROBLEMS FACED

The fundamental challenge that is being noticed is that after the melting of the aluminiums, the workshop is always hot

Another occurring challenge the producers do face is the problem of financial support. Financial support in the sense that at times, they are unable to buy/purchase the used aluminum materials or the used engines from the mechanics/the market.

sometimes these the raw materials (aluminum scraps) for the production becomes scarce in the market and as a result the producer have to look for an alternative as they sometimes travel to several places mostly long distance journey to purchase the aluminum waste (scraps) which attracts extra cost due to the transportation charges thus leading to an increase in both the production cost and prices of the pot.

Another challenge faced by the potters is when they make mistake(s) in the process of molding whereby the potters is left with no other option than to re-melt the pot for correction which later attracts additional quantity of aluminum to make such correction leading to extra or additional resources wasted. For example if one is to use I kilo for the production of one pot but due to the mistake made in the process of producing that pot, one may end up using 1 ¼ or 1 ½ kilo of the aluminum. And that attracts additional cost of production and at the end it would be sold at the normal price and they (the producer) will be at a loss, instead of making profit.

In summary, the problems faced by the industry are technical, operational, organizational and financial in nature. The strategies for ameliorating the problems are established. It was concluded that improved policies, carefully crafted projects and proper management of technology can drastically solve these problems

possible defects of the product

Fluxing capabilities is reduced when the only way of removing impurities is visual stirring and approval; there is no certainty that all the metals have melted and all the impurities have been removed. Likewise de-molding after the pouring, there is an unpredictable procedure and there might be some deficiencies like; laps, seams, cracks, inclusion and under fill. Visual scanning and inspection determines only the surface defects. Lifting the pot upside down towards the sky reveals the tiniest holes.

marketing and Patronage

Local crafts generally are appreciated in the present day market. Likewise the local cast aluminum pots making is a modern craft whose products are thriving in the markets. The products which include cooking wares and utensils of various sizes as well known and patronized by a good number of buyers especially in the western part of this country. In a nutshell, they are basically used in homes for cooking.

Even with the advent of modern machine made aluminum kitchen utensils that come in different sizes and in attractive designs, the patronage of the locally produced or molded pots are still very high due to it retentive qualities;

Ø These pots are very strong and can be used either on local or kerosene stove".

Ø No leakage

Ø Are cheaper than the modern machine made ones.

So when a customer buys these locally produced ones, one saves a lot of money that he\ she can use for other important purposes

At times several group of association mostly the women associations are always known for the habit of patronizing this people with the sole aim of using it as a present to a celebrity during a celebration or during anniversaries. At times they distribute them to the people who are present during that occasion.

adaptation in contemporary world

Talking on the quality of these pots, the pots can be used everywhere and it has one advantage because when these pots are old or damaged they can be sold as scraps to the producers for recycling or a user can give half of the amount with the old or damaged pot in an exchange for a brand new one (i.e. There is no room for waste of resources)

During my findings, I noticed that travelling to this place to seek for information, this people are usually biased with the little information they have for their product. Thus they prefer to give the information out to the white (Americans), because at least they would have at least some dollars/pounds and whatever at the end of their conversation. Meanwhile, it shouldn’t be done that way. Whereas, my going there is to seek for information on how this wonderful craft is being made is not to harm them. Also I search through the websites to seek for more references but to my surprise, there is no genuine information. The point am driving at is that if this craft is given the chance, at least they should be able to boost the country in terms of basic amenities, add more values to the countries economy and growth of the country. To me, this is a craft a country should be proud of. Only that the people producing this craft are illiterate.

RECCOMMENDATION AND CONCLUSION

Apparently, there is an abundance of easily identifiable enhancement opportunity at the foundry. But when the restraint of capital flow to acquire equipments and supplies from other parts of the nation is considered, the opportunities disappear. But the realities of the existing circumstances indicate that the implementation of these improvements can be of greater problems. To improve on the fluidity of the molten metal and more than double the temperature range between the liquids and solids, a good percentage of silicon can be added.

However, if all these procedures and measures could be implemented, consequently it will improve the quality of the cast aluminum products in this locality, thereby creating arena whereby the taste and the demand of the even high class consumers will be met.

REFERENCES

Ababio o.y, (1990) “General chemistry” Lagos: Longman press

Lewin, Seymour Z. "Aluminum." Microsoft® Encarta® 2009 [DVD].

Redmond, WA: Microsoft Corporation, 2008.

Malyn D.D.Newitt "Casting." Microsoft® Encarta® 2009 [DVD]. Redmond,

WA: Microsoft Corporation, 2008.

Murjanatu Mohammed A. Nigeria: Inside Kaduna's Aluminum Pot Market (9

September 2008).cited from www.Allafrica.com

S. A. Ibitoye and M. O. Ilori ‘Indigenous metal casting in Nigeria: its technology, attendant problems, business prospects and policy implications’ (Volume 18, Issue 11, November 1998, Pages 705-711)