Successful Pin Brazing

The key to successful Pin Brazing as with traditional Brazing techniques relies upon many key factors and there are several main factors, but when it comes to Pin Brazing there are just five areas on which I primarily focus when providing training classes or presentations. These are Power Supply, Surface Preparation for your connection, Surface Preparation for your Earth Device, having the correct Adjustment Setup and finally Operator Proficiency. The above factors can often be overlooked individually, often creating inadequate results and expensive delays so it is important that both operators and companies ensure that they have either received or made provision for training and certification by a qualified, experienced Instructor.

Not wanting to make this article into an 'instruction manual' it is my intention to focus on in more detail why some of the above factors are imperative considerations in both Pin Brazing product design and development and the consideration that must be given when taking the responsibility to develop and pioneer these innovative processes.

Connection Design.

Brazed joints using Silver based Filler metals should always have a capillary gap into which the molten filler metal can flow. Joint strength will vary with the joint gap and the degree of overlap between Connection type and parent metal, joint clearances of 0.03 to 0.08 mm (0.0012 to 0.0031 in) are recommended for the best capillary action and joint strength.During the Pin Brazing process, brazing material is drawn into the joint which is caused by the attraction between the molecules of the brazing material and the molecules of the metal surface to be joined. This will only work if: The surface of the metal is clean, the clearance between the metal surfaces is correct and the metal at the joint area is hot enough to allow the Pin Brazing material to evenly flow. Connection methods such as Crimp Terminals should be precision manufactured to ensure optimum capillary gap for joint strength and integrity, whilst also allowing excess heat created during initiation of the Pin Brazing Arc to flow freely away from the Substrate material in order reducing and unnecessary damage or increased Heat Affected Zone (HAZ).

Brazing Pins and their respective Alloys should be selected on their suitability for a particular application. Consideration should be given to the substrate design, the parent metal, the brazing process and the ergonomics of the operation. The use of Cadmium free, high Silver, free flowing filler Alloys with low melting ranges are essential in the development of Brazing Pins, which aid in the shielding of the Parent material during the Arc process and allow for an increased flow maximizing in the available surface area, which in turn allows for a more substantial electrical and mechanical connection.

In the Manufacture of Brazing Pins the choice of flux is as important as the choice of filler metal. The working range of the flux must be compatible with the brazing temperature, must have suitable life at temperature and should be suitable for both the heating method (in the case of Pin Brazing, Arc temperature could be in excess of 2000 Degrees Celsius) and the parent metals and become active below the melting point of the brazing alloy. It must stay active right through the brazing cycle removing any oxides formed on the parent metal. Observations should be made if the flux residues appear blackened and glassy as the flux has probably been exhausted during heating. This could be the result of contaminated flux (from very old or incorrectly stored Brazing Pins) or more likely the components have been overheated, possibly due to an incorrect adjustment setting on the Brazing Gun or an un-charged Battery Pack.

Pre-cleaning.

To promote good bonding the connection substrate should be free from grease and any surface oxide prior to brazing. Grease and oil are best removed using a degreasing solvent. Prior to this Pin Brazing Ancillaries can be used which will often include Surface Preparation Equipment such as Die Grinders and Angle Grinders fitted with Carbide Burrs, Mounted Points or abrasive Flap Discs. These mechanical surface preparation devices are intended to be utilized sparingly in order to not cause disruption to the substrate thickness or create uneven pits or troughs which may interfere with Capillary action or Arc length. Surface oxide can also be removed with a medium grade abrasive cloth. Consideration should also to be given to Consumable quality, as with Substrate material, components which have been exposed to moisture or grease can be the cause of defective brazes results. Care should be taken at all times to ensure that Consumables remain sealed in their original containers until required for use and should be inspected for surface oxidization or grease prior to being used.

Battery Status.

Most standard Pin Brazing Systems operate using a 36-42volt Battery Pack or Welding Generator set up to mirror the characteristics of the Battery pack. Careful consideration and testing has gone in to find batteries that are suitable for the extreme operational demands of the Pin Brazing Process and the equally extreme environments in which the process is utilised. Therefore only pre-approved batteries must be used, these battery types or their details will only be obtainable from your Pin Brazing Supplier or equipment manufacturer and it is important to note that different Pin Brazing Equipment Manufacturers do utilise different Battery types, which are attuned for use with only their respective tools and consumables. As a user batteries must be cared for in accordance with your user manual, and even under heavy usage could last for many years.

Vacuum Cleaners Technologies

The history of vacuum cleaner technology dates back about a century and a half. The modern vacuum cleaner was born from the fruits of original carpet sweepers in the middle of the nineteenth century. Beginning originally with manually rotated sweepers and suction (often operated by a hand pump), they would give way to motorized systems that use pressure differentials to create suction from high pressure to low pressure areas in the early twentieth century. Over time, the vacuum cleaner has continued to evolve. This has occurred to the point where multiple modern technologies have emerged for current vacuum cleaners, each of which can be found in houses and businesses across the United States. Here is a look at some of those technologies.

Upright: These represent the most common form of vacuum cleaners and the one that most people associate with the term. They are named so because they obviously stand upright and are typically used at an angle after pressing on a release lever. Compared to other vacuum cleaners, they are popular primarily because they offer a nice balance of cleaning power in a compact system (waste receptacle connected to same frame as hoses and sweeper nozzle) that can be easily stored.

Canister: Canister vacuums tend to operate in two separate sections. The main canister region creates the suction and holds the dust, dirt, or other collected waste. Meanwhile, the powerhead and pole operate more freely and are attached only by connecting hose and power cord. They offer a little more freedom in terms of floor/ground that can be covered, but they are also more awkward and difficult to move around compared to an upright system.

Central: These systems have their primary cylinder and motor built into a certain area. The hose is either attached directly to this central unit or to ducts located throughout the building. The hose and cleaning head can be attached to the most convenient local location and the dirty and waste will be collected and sent back to the central unit for holding. These operate many advantages in terms of cleaning capacity, allergic problems, and noise reduction, but also greatly reduce flexibility and are much more expensive compared to the self contained models.

Cyclonic: This is the system that was popularized by James Dyson. Rather than use bags to collect the dust and dirty, this system creates a miniature cyclone within the holding tank that spins the collected air to separate out the dust and dirt. Due to centrifugal force, these particles are pushed to the outer portion of the container. When the vacuum is turned off, the cyclone ends and one can just remove the canister and dump out the waste into a trash receptacle.

Robotic: Of all modern vacuums, these are the most fun. The most common forms are small discs that operate on their own, going around the building collecting little particles while bumping off walls and edges. Unfortunately, at this time, they still are not the most effective form of vacuuming and can even become stuck at times.

List of Artificial Heat Sources

Winter is coming on fast - just a few weeks away at the time this goes to press (so to speak). As such, millions of Americans are beginning to turn the heat on in their homes. This is typically done with a simple flip of the switch at the thermostat. But the actual methods for heating are much more diverse. Throughout time, man has developed many ways to stay warm when the elements turn against him. Here is a look some of today's most common sources for staying warm:

Wood/Coal: These are the oldest methods for heating - especially wood, which dates back to the time when man first harnessed fire itself. At their essence, these are sources for heating because of their ability to burn for extended periods. In the early days of human society, wood was the primary (and often only) source for heating homes during a winter climate, often through the use of a wood burning stove. As mining methods improved and coal extraction became more prevalent, coal has been used in the same manner. Coal is a more efficient burner thanks to its ability to have smaller amounts burn for a longer period when compared to wood. These are still used extensively for rural heating, but due to cost of use and storage - they are now used much less in urban settings compared to centuries passed.

Electric: Electricity has become the most common method of heating in the modern world. An unintentional, but unavoidable, result byproduct of Edison's light bulb invention was that it gave off a tremendous amount of heat. This is still true of the design today - as any female who ever used an easy-bake oven is aware. While it is viewed as inefficiency with regard to light production (wasted energy), it is the basis for how this energy can be produced specifically for home warmth through heating coils. Electric heat has advantages in that it is more abundant than other sources of energy, but it lacks efficiency compared to some other formats.

Oil/Gas: Fossil fuels still represent the most efficient form of energy. They burn the hotter and longer compared to other affordable resources that are available at this time. Natural gas is especially popular as a central heating source for modern homes. Due to the abundance of natural gas within US borders and political issues surrounding the reliance on foreign oil, gas figures to take an even broader role in the coming years. There is the downside of pollutants (less so with natural gas compared to oil) and the fact that they are finite in quantity.

Geothermal: It is interesting that most emergent form of heat is one of the oldest and the simplest. Geothermal heat is obtained by drilling down and obtaining heat from within the Earth. This is increasing in popularity due to its environmental advantages vs. other forms of heat and virtually no offsetting pollution. However, it is not yet feasible for all communities and still has a bit to go before it becomes cost efficient for most users.