Brazing Copper: A Comprehensive Guide and Overview

Brazing copper is a process where metal is joined by a filler metal. It is heated above a melting point and distributed between two or more parts. The filler metal is generally slightly above its melting temperature and is protected by a suitable atmosphere. It flows over the base metal—also known as a wetting—and is cooled in order to keep the pieces working together.

Brazing is very similar to soldering. Soldering is a process where two or more metal items are joined together by melting and flowing a filler metal—known as a solder—into the joint, with the filler metal having a lower melting point than the contiguous metal.

The one main difference between brazing copper and soldering is its temperature. When it comes to brazing, the filler metal temperature is higher.

What is important to know about brazing? 

Well, for one thing, obtaining high-quality brazed joints requires parts to be closely fitted. The base metals must be clean and oxide-free. One of the most important parts of brazing is the joint clearance.
What are the recommended joint clearances for brazing?

For brazing, the recommended joint clearances are 0.03 to 0.08 mm, or 0.0012 to 0.0031 in. This is for the best capillary action and joint strength.

What is capillary action?

Capillary action is the ability of a liquid to flow in narrow spaces, without the assistance or opposition of gravity.

What can cause faulty joints?

Faulty joints can be caused by a myriad of various reasons, including improper joint preparation prior to brazing, lack of proper support, improper heat control and distribution, inadequate amount of filler metal applied, and sudden shock cooling.

What are some common types of brazing?

When it comes to brazing copper, some companies specialize in furnace type and some by using the resistance method.  When brazing copper or any precious metals, the brazing of the copper or other metal to each other can be tricky and is a critical part of the process.  Depending on the method of brazing the copper, this will determine whether the copper and other metal are held in place by jigs or by pressure, at least until the brazing is complete. This is common for use when brazing copper to a more expensive metal such as silver alloy for use in making electrical contacts. This allows for electrical contacts to meet the important precious metal content requirement while brazing the copper to the contact material allows for the remaining part of the contact’s design to be formed as needed
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Which industries typically implement the use of copper brazing? 

Quite a few, but some of the most common include the plumbing industry, automotive industry, and the HVAC (heating ventilation and air conditioning) industry.

Brazing copper is one of the most common methods of joining copper tubes and fittings. When brazing copper, it is important to braze the assembly to at least 800° F. However, it is important to use a filler metal that will melt above 800° F, but will be below the melting point of the metals to be joined.

John Bowie works in the HVAC industry where he frequently works with metal joining processes. He is quite familiar with brazing copper as a part of his occupation. On the side, John Bowie enjoys writing about HVAC and technical-related topics to inform others.

Merseyside Maritime Museum School Day Trip

Merseyside’s maritime heritage can be explored with a day trip from Selwyn’s Tours. Students can see replicas from the tales of the Titanic, shanties, smuggling, and sea dogs at the museum. They can get a feel of the central role that was played by Liverpool in the Civil War in America or The Atlantic Battle. A tour of the Liverpool pilot cutter that is moored at the dock is another ship to visit. A trip to the adjacent Pier Master’s House where they can see how the pier master controlled traffic that is routed through the dock can edify their young minds. Selwyn’s Tours can transport your students on this educational trip.

If you are of the opinion that the high seas tales were from yesteryear, you will be totally amazed at the discovery that tax evasion, smuggling, war, and protests, as well as some of the ways and objects that were used in the smuggling of contraband items in those days are still being done today. This can be seen at “Seized! The Border and Customs Uncovered”.

This is a gallery at the museum that details the Custom Officer’s world. It tells of danger and intrigue and presents a key theme on anti-smuggling. It shows detectives at work, fighting crime, patrolling the frontiers and investigating crimes. The tactics that were employed in those days are quite similar to those used today by criminals of the sea and land.

They balance the view of the past with a contemporary story and look at issues of safety and fairness in the society that affects all today. The young visitors can download Matt’s Gallery Trail, or get to test their handling skills at cargo landing with the museum’s Cargo-a-go-go game, which is fairly new.

Educational, fun, and enlightening, a Merseyside Maritime Museum School Day Trip can be one of the most popular attractions in Liverpool. The entry for the museum and the Old Dock tour, which can be organized by the museum workers, is free. The booking should be done in advance. Opening hours are between 10 am and 5 pm on a daily basis. The quayside and ships are closed during winter season. They provide free lessons and the curriculum is linked by displays and collections.

Some sessions are done by members of the museum staff, while others are done by the individuals or group. Topics such as pirates, World War II, or the Titanic are included. Home office issues are discussed in approved sessions targeting drugs, weapons, and alcohol awareness.

Whatever type of trip you decide to plan for, Selwyns’ personalized, expert service can ensure you a safe and smooth trip.

Selwyn’s removes the worry from the planning process of your trip. Plan a trip for January 2014, contact them, and rest assured that everything will be taken care of. They provide coach and bus hire service for over forty years at an economical price. They have coach hire services based in Manchester, Liverpool, and Runcorn. They can get you to the destination comfortably and safely. Even though their location is in the North West, they can take you all over the UK.

History mystery: Interesting Discoveries of Sibudu Cave

At Sibudu Cave we find record of prehistoric human occupation which dates back 77,000 years ago or even much longer. It is a rock shelter in a sandstone cliff situated in northern KwaZulu-Natal in South Africa. It shows evidence of some of the earliest examples of modern human technology, the spears date back 400,000 years, the bone arrows around 61,000 years old, the use of heat treated mixed compound gluing to 72,000 years, an example of bedding around 77,000 years and the needle 61,000 years old. 

The complexity of creation and processing in glues and bedding is of great interest and has evidence of continuity between the early human cognition and the present humans. Besides the spears and arrows, they also have sophisticated stone tools as well as skillfully made bone implements, deep hearths, charred bones of big and small mammals, blocks of red ochre as well as sparkling ornamental beads made from shells of sea snails, bedding made of sedges and grass and other monocotyledons together with some aromatic leaves containing insecticidal and larvicidal chemicals while the leaves from Cryptocarya woodii Engi when crushed were aromatic and had traces of a-purones, cryptofolione and goniothalamin which are useful as insect repellant. 

Sibudu Cave being a rock shelter is located roughly 40 km north of the city of Durban and around 15 km inland near Tongaat town. Its steep forested cliff faces WSW which overlooks the Tongati River which presently is a sugar cane plantation. Due to erosion of the Tongati River, this shelter was formed and it now lies 10 m below the shelter and its floor is 55 m long and around 18 m wide. The shelter has a large collection of Middle Stone Age deposits which are well preserved organically and dated accurately using optically stimulated luminescence. The occupation at Sibudu is divided into pre Still Bay between 72,000 - 71,000 BP, Howieson Poort before 61,000 BP, post Howiesons Poort in 58,500 BP, and late 47,700 BP and finally the Middle Stone Age era in 38,600 BP with occupation gaps of almost 10,000 years between the post Howiesons Poort and the late Middle Stone Age era and the late and final Middle Stone Age period. 

The occupation during pre Still Bay had lithic flake based industry which made few tools and in addition to flakes, made bifacial tools and points where the tips of the points shows evidence of compound adhesives on their base when they were hafted and shafted. The Howiesons Poort occupation made blade tools which were shaped like the segment of an orange with sharp cutting edges on the straight lateral with a blunted and curved back. 

These were attached to handles with ochre and plant adhesive or fat mixed with plant material. The segments were made with a cutting edge all along the length which needed to be attached to their hafts without the need of twine and hence strong adhesive glue was essential. Discoveries show that there were dry phases and the shelter was occupied only during wet climate. The first excavation after its discovery was carried out by Aron Mazel of the Natal Museum in 1983 an unpublished work and Lyn Wadley of the University of the Witwatersrand began a renewed excavation in September 1998.

History mystery: Neolithic structure in Goseck Circle

A Neolithic structure in Goseck in the Burgenlandkrejs district in Saxony Anhalt, Germany named Goseck Circle is one of the oldest, best known Circular enclosures connected with the Central European Neolithic. It is an early Neolithic circular structure with entrances adapted to the rising and setting winter solstice sun. It comprises of a set of concentric ditches of 75 meters (around 246 ft approx.) across and two palisade rings with gates in places aligned with sunrise and sunset on solstice days. It lies on the same latitude as Stonehenge at 51° 10’ 42” N 1° 49.4’W) just over 1’ minute of longitude further north. It is known as the earliest solar observatory presently known. When archaeologist decided to excavate this 7000 year old circular enclosure, they did not expect to find any major discoveries which would be worth mentioning the history of Neolithic Europe. As they proceeded with the excavation, they soon discovered that the two southern gates of the henge marked the beginning of the summer and winter solstice which made the enclosure one of the world’s oldest solar observatories. 

It was one of the oldest known constructions with this type of astronomical alignment dating back to the 49th century BC which seemed to be in use till the 47th century and relates to the transitional phase of the Neolithic Linear Pottery and the Stroke ornamented ware cultures. This so called Circular Enclosures is one of the larger groups in the Elbe and Danube region, most of them having similar alignments. Hundred of similar wooden circular henges together with the Goseck enclosure were built throughout Austria, Germany and the Czech Republic around 4600 BC and while these sites vary in size, Goseck is around 220 feet in diameter and they all have the same features. They have a narrow ditch surrounding the circular wooden wall and a few larger gates which are equally placed around the outer edge. 

While scholars had known about the structure for centuries, they were debating as to their exact function within the Stroke Ornamented Pottery culture which dominated Central Europe during that time. The Goseck circle helped to provide an answer and as one of the researched enclosure which was well preserved, showed that the sites were used at least in parts to worship celestial objects and constellation. According to Biehl, the archaeologist, this was perhaps the first monumental architecture in the world from his observance that the sites served as ritual observatories 2000 years ago before the ancient Egyptian pyramid were erected along the Nile. After its initial research release on the Goseck structure in 2003, by the Halle team, interest mounted in the enclosure with thousand of tourist visiting that area which is located around 40 miles southwest of Leipzig and although the site predates monuments in southern England of more than two millennia, there is no evidence of any standing stones there. To satisfy the growing interest in this site, the German state of Saxon, Anhalt built a structure of the enclosure on the original site and to ensure authenticity, 2000 oak post were stripped by hand by workmen to give it the same appearance during the Neolithic times. This site was made public in August 2003 and opened for visitors in December 2005.

History mystery: Dholavira remains of a lost civilization

One of the most prominent and largest archaeological sites is Dholavira, an ancient metropolitan city in India, also locally known as Kotada Timba Prachin Mahanagar Dholavira which existed during the Indus Valley civilization. It was located on the Khadir Island in the Kutch district of Gujarat and is surrounded by water during monsoon season. The ancient site of Dholavira which was discovered in 1960 is separated by two storm water channels, the Manhar in the south and the Mansar in the north. It is the fifth largest Harappa site in the Indian subcontinent which has been continuously under excavation since 1990 by Archaeological Survey of India. The excavation revealed the sophisticated urban planning and the architecture has unearthed a huge collection of antiquities like seals, animal bones, beads, gold, silver, terracotta ornaments and vessels of Mesopotamia.

The archaeologists also believed that Dholavira was an important trading centre between settlements in South – Gujarat, Sindh and Punjab region and Western Asia. Being identified as one of the five largest Harappa sites it gives us details of a civilization which flourished across India, Afghanistan and Pakistan. Dholavira was a city or a metropolis and according to archaeologist, its estimated population was between 15000 to 20000 inhabitants. A good amount of evidence is available about the site which indicated that the geography of this site was a lot different 4000 years ago. In the museum, which is small but informative, large sized conch shells excavated from the site as well as piece of a rock used in the construction of a wall bearing fossilized marks on seashells are placed there, which indicates the presence of a sea coast not far from this site. Moreover the museum also displays a large number of broken pieces of bangles and beads made from shells. A fossilized rock formed by a cluster of sea shells is also displayed. These excavations clearly indicate that Dholavira was a port city located near the sea coast where ships often sailed. It also indicates that it was a trading center which also explains the large population of this city.

It was believed that Dholavira was a port and the Khadir Bet was located at a distance of more than 150 km from nearest port of Lakhpat in the Kori Creek area, towards the Arabian Sea, where no water body seems to be present between the two areas. The Rann of Kutch divided into two unequal halves, Greater and Little Rann, is a unique piece of landmass with its mean height roughly equal to the mean sea level. The south western wind during summer pushed the water of Arabian Sea through Kori creek, submerging the Rann for few months and during monsoon, the seasonal rivers like Luni surrounding it, emptied into the Rann where the water column height varied between 3 to 6 feet over the Rann though it is a seasonal phenomenon. At the end of the monsoon, the water recedes drying up the area leaving behind flat ground impregnated with salt. Taking these situations in mind, it is clear that there no port could exist near Dholavira and if so, the graphical situation could have been different then.

Filioque

The Filioque controversy probably has to do with the Latin phrase which when translated as `and the Son’, was added to the Nicene Creed by the Western churches and opposed by the Eastern churches. The Nicene Creed was then confirmed by the First Council of Constantinople in 381 and with the “filioque” was accepted by the Western churches after the Synod of Toledo in Spain in 589:- “We believe in the Holy Spirit, the Lord and the Giver of Life, who proceeds from the Father, who with the Father and the Son is worshipped and glorified”. This extract refers to the doctrine of the procession of the Holy Spirit from the Father and the Son.

It was opposed by Photius, the patriarch of Constantinople in 867 and 879 and was not accepted on two reasons namely, i) the addition was made unilaterally, changing a creed which was approved by early ecumenical councils and ii) the formula reflected a particular western conception of the Trinity which was objected by most of the Byzantine theologians. This theological dispute between the two churches in the West and East was a bit subtle when it came to dealing with the Godhead persons and the mystery of the Trinity and it became a continuous friction between them which resulted in an official cause of the Great Schism in 1054 AD.

 Photius had excluded not only `and the Son’, but also `through the Son’, relating to the procession of the Holy Spirit and `through the Son’, was applicable to the temporal mission of the Holy Spirit. According to him, the eternal procession of the Holy Spirit is `from the Father alone’. The Orthodox theologians believe that the phrase was only a reaffirmation of traditional teaching while on the other hand; Sergei Bulgakoy declared that Photius’s doctrine represented a novelty for the Eastern Church. Pontius has been recognized as a saint by the Eastern Orthodox Church and his criticism has made reconciliation between the East and the West a difficult task and the two churches are still in disagreement over the issue of Filioque controversy. Scripture reading in John 14:26 tells us that `the Counselor, the Holy Spirit, whom the Father will send in my name’ and in John 15:26 `When the Counselor comes, whom I will send to you from the Father, the Spirit of truth who goes out from the Father, He will testify about me’, indicates that the Spirit is sent out by the Father and the Son.

 The concern in the filioque clause is to protect the presence of the Holy Spirit and the Bible in Acts 5:3-4 states that the Holy Spirit is God. Those opposing the filioque clause object since they believe that the Holy Spirit proceeding from the Father and the Son is the Holy Spirit who is `Subservient’, to the Father as well as the Son. Those upholding this controversy believe that the Holy Spirit proceeding from the Father and the Son do not believe that the Spirit is equal to God with the Father and the Son. The filioque was probably devised in response to Arianism who denied the divinity of the Holy Spirit.

 Unsuccessful attempt was made to bring about an understanding between the two points of view by the Council of Ferrara- Florence in1439 but the eastern and the Western churches remain separate and the doctrine of filioque remains as one of the most primary point of difference between these two churches. The doctrine of filioque controversy relates to the presence of God’s person which itself is a divine mystery, incomprehensible to man since God being infinite and immortal is most incomprehensible to us, mortal beings.

The Holy Spirit is God, sent by God as Jesus Christ’s representative here on earth when He ascended into Heaven after His Resurrection from his death on the Cross. Presently many Eastern Orthodox bishops are overlooking their old prejudices and are acknowledging that there is no need for separation on the issue of the filioque controversy. Bishop Kallistos Ware who had opposed the filioque doctrine remarks that the filioque controversy which separated the two churches for many centuries is a mere technical issue with a solution.

According to him the problem was more in the area of semantics and different emphases than in any basic doctrine differences. Towards 1014, the German King Henry II who came to Rome to be crowned Emperor was amazed at the different custom present there and requested Pope Benedict VIII who owned King Henry his restoration to the papal throne after the seizure of Antipope Gregory VI, had the Creed with the addition of the Filioque which was sung during Mass in Rome for the first time and in other places the filioque was incorporated in the Creed later. The Filioque clause since then has been included in the Creed throughout the Latin Rite but not where Greek liturgy is used though it was never adopted by Eastern Catholic churches.

History mystery: Hypocaust

Hypocaust, one of the ancient forms of heating system in underground heating with hot air, originated with the Romans, 2000 years ago and was both a primary as well as secondary system for houses and building for both public and private purpose. Hypocaust is derived from the Greek work `hypo’ meaning `under’ and `caust’ meaning `burnt’. The main use of hypocaust was found in large bath houses and sauna rooms were made by adding water as a pool which was heated by fire and also the air below. The floor was raised above ground level by pillars, or columns or pedestals of stone, called pile stack which had layer of tiles, followed by layer of concrete to top the tile.

 A furnace with continuous burning fire created heat which then flowed through the space below the raised floor, providing heat to the floor and the rest of the room and once cooled the air escaped through flues in the wall and through vents in the roof. Since the furnace area needed to be spacious, it was usually located in a separate area of the room and the flues were constructed in a way that it did not utilize any extra space. This enabled the heating without polluting the interior of the room. Ceramic box tiles were also placed inside the walls in order to remove the hot burned air as well as to heat the walls and where rooms in need of more heat, were placed closer to the furnace.

This heat could be increased on adding more wood to the fuel. This involved a lot of labor and constant attention was needed to keep the fire burning as well as expensive. The purpose of the hypocaust was to heat the room evenly. Similar to the water system, the air flow system was also connected by ducts comprising of brick or stone tunnels built underground towards large open space beneath raised floor ending into wall flues. These flues were provided with insulation for the room and the hot air rising created a barrier thereby retaining the warmth inside the building. One of the main disadvantages of the hypocaust was that it seemed dangerous when the fumes created by the furnace in the form of carbon monoxide crept out of the spaces below the false floor and in the main space and though this is detectable and preventable today, in those days, the Romans had no knowledge about the same. Another disadvantage was that with this system, there could have been the possibility of a fire break out which could be unmanageable and out of control. While the concrete or stone construction could have withstood the fire, the occupants would be in danger.

This system seemed to be useful in ancient times but keeping in mind the safety codes, it is impossible to install them in modern times since the hypocaust system in high probability would be causing the occupant discomfort resulting in falling ill or even the possibility of dying from carbon dioxide or poisoning. Control on the hypocaust system is not user controlled due to the fact of the heat coming off from an open flame and for this reason; there are two setting for this system of on and off.