http://slots.us.org

Saturday, August 30, 2014

Arc Welding A How To Arc Weld Guide

Arc welding is probably the most easily and readily available welding process on the face of the earth. Just about anyone can get access to an arc welder. Arc welding is also called stick welding, and the technical name for this welding process is manual metal arc welding or MMAW for short.

But don't go around town saying that you can do or are doing MMAW welding or that you are doing manual metal arc welding. People will look at you and think you are a few beers short of a six pack.

Wednesday, August 27, 2014

How to Arc Weld and Stick Weld

Learning how to weld is not as hard as you might think.

All you have to do is simply follow a few basic steps, to get that welding down pat. It's like baking a cake or building a house. You need to follow a set way of doing things.

There are a few basic and easy to learn steps that you need to take into consideration before you even attempt how to stick weld or arc weld.

A lot of the time, people simply just rush in "guns blazing" and when they have a go at it half a dozen times and they can't do it, they give up. Listen, like I've said, stick welding might seem a bit daunting at first. But once you learn these basic steps on how to arc / stick weld the whole process will become a lot clearer to you.

Tuesday, August 26, 2014

Learning How to Arc Weld is Fun and Easy

Learning how to weld is really not that difficult. Most welders learn arc welding first. The easiest way to start welding is simply by practicing. You can pickup a cheap arc welder from somewhere like harborfreight tools. It will cost you under $120.

You will also need a welding helmet, welding gloves, a heavy jacket and some welding rods. Take my advice, spend the extra money and get an auto darkening helmet. It will make learning so much easier. You will also want to get a supply of scrap steel to practice on. This can be picked up at a scrap yard.

Monday, August 25, 2014

Arc Welding Fundamentals


Arc welding is one of several fusion processes for joining metals. By applying intense heat, metal at the joint between two parts is melted and caused to intermix - directly, or more commonly, with an intermediate molten filler metal. Upon cooling and solidification, a metallurgical bond is created. Since the joining is an intermixture of metals, the final weldment potentially has the same strength properties as the metal of the parts. This is in sharp contrast to non-fusion processes of joining (i.e. soldering, brazing etc.) in which the mechanical and physical properties of the base materials cannot be duplicated at the joint.

In arc welding, the intense heat needed to melt metal is produced by an electric arc. The arc is formed between the actual work and an electrode (stick or wire) that is manually or mechanically guided along the joint. The electrode can either be a rod with the purpose of simply carrying the current between the tip and the work. Or, it may be a specially prepared rod or wire that not only conducts the current but also melts and supplies filler metal to the joint. Most welding in the manufacture of steel products uses the second type of electrode.


Basic Welding Circuit
The basic arc-welding circuit is illustrated in Fig. 1. An AC or DC power source, fitted with whatever controls may be needed, is connected by a work cable to the workpiece and by a "hot" cable to an electrode holder of some type, which makes an electrical contact with the welding electrode.

An arc is created across the gap when the energized circuit and the electrode tip touches the workpiece and is withdrawn, yet still with in close contact.

The arc produces a temperature of about 6500ºF at the tip. This heat melts both the base metal and the electrode, producing a pool of molten metal sometimes called a "crater." The crater solidifies behind the electrode as it is moved along the joint. The result is a fusion bond.


Arc Shielding
However, joining metals requires more than moving an electrode along a joint. Metals at high temperatures tend to react chemically with elements in the air - oxygen and nitrogen. When metal in the molten pool comes into contact with air, oxides and nitrides form which destroy the strength and toughness of the weld joint. Therefore, many arc-welding processes provide some means of covering the arc and the molten pool with a protective shield of gas, vapor, or slag. This is called arc shielding. This shielding prevents or minimizes contact of the molten metal with air. Shielding also may improve the weld. An example is a granular flux, which actually adds deoxidizers to the weld

The shielding of the welding arc and molten pool with a Stick electrode. The extruded covering on the filler metal rod, provides a shielding gas at the point of contact while the slag protects the fresh weld from the air.


The arc itself is a very complex phenomenon. In-depth understanding of the physics of the arc is of little value to the welder, but some knowledge of its general characteristics can be useful.

Can arc welding be performed in water?

The process of performing arc welding in water is known as underwater welding which is a highly specialized and useful technology available to assemble or repair under water. This method of welding is mostly used in oil or shipping industry, military applications and in maintaining underwater pipelines. It is also used to repair ships that are damaged during wars or hurricanes. 

Under water welding functions in the following manner:
One side of the electric circuit is connected to the work to be welded and the other end is connected to a metal electrode. These two parts are brought together and then separated to some extent in which the electric current jumps and causes an arc. This arc melts the bare metal thereby causing a weld pool. Simultaneously the tip of electrode also melts and the metal droplets are projected into the weld pool during which the flux covering the electrode melts to form a shielding gas. The gas stabilizes the arc column and protects the metal. 

Sunday, August 24, 2014

A complete note on Arc welding

Arc welding is a huge process wherein electric arcs concentrated heat is used for metals are joined by the parent's fusion and all the additional metals to be added to join usually provided by a very strong consumable electrode. For an arc current used is ether alternating or a direct current, it also depends on the material and also the electrode used.

Electroslag welding is a very keen process of welding. Electroslag welding {esw} does a important work of depositing two metals into the very own weld cavity which is between the two plates which has to be joined. To enclose the space by water or copper damn or else shoes so that molten slag could be prevented from running off. An initial arc which is formed from a filler wire with a piece of work and it is done till a sufficient pool of liquid metal is formed which is also used for the molten slag s electrical resistance. This type ofis a very Arc welding huge process.

Saturday, August 23, 2014

Volt-Ampere Characteristics of a Welding Power Source

Volt-Ampere Characteristics of a Welding Power Source

All welding power sources have two kinds of operating characteristics viz., static characteristic and dynamic characteristic. The static output characteristic can be easily established by measuring the steady-state output voltage and current by conventional method of loading by variable resistors. Thus, a curve showing the output current versus output voltage for a given power source constitutes its static characteristic.

The dynamic characteristic of an arc welding power source is determined by recording the transient variations occurring over a short intervals in the welding current and the arc voltage. Thus, it describes instantaneous variations occurring over a short interval of time say a millisecond. Arc stability is determined by the combined interaction of the static and dynamic colt ampere (V-I) characteristics of the welding machine power source.

How to Strike an Arc When Arc Welding

Learning how to properly strike an arc when arc welding can be quite a headache. There are a few methods to strike an arc and we will go over them here. The one thing that probably makes it the most difficult is that you cannot see what you are doing, so I strongly recommend getting an auto darkening welding helmet. It will probably be the most important investment you will make on your quest to learn how to arc weld.

The basic theory behind how to strike an arc is simple. You must make the metal of the electrode contact the metal you are welding on. It must then be immediately drawn away from the metal about 1/4 of an inch. If you do not draw it away it will simply stick to your work. If that happens a quick twist and tug will usually get it loose. If it doesn't break free on the first try you will want to squeeze the clamp on the electrode holder and pull that away. Keep in mind any time the electrode is stuck to your work, the welder is being shorted out. This will cause it to overheat much quicker, and may blow a fuse or breaker in your breaker box. 

Friday, August 22, 2014

About Arc Welding

Arc welding is probably the most easily and readily available welding process on the face of the earth. Just about anyone can get access to an arc welder. Arc welding is also called stick welding, and the technical name for this welding process is manual metal arc welding or MMAW for short.

But don't go around town saying that you can do or are doing MMAW welding or that you are doing manual metal arc welding. People will look at you and think you are a few beers short of a six pack.

Arc Welding Machine Power Source

For striking a welding arc it is essential to have the desired current in the welding circuit. Depending upon the type of current required (ac or dc) it may be obtained from the following sources.


  • A welding machine or frequency changer (for ac welding machine).
  • A dc generator of a welding rectifier (for dc welding).
  • The no load or open circuit voltage (OCV) should be high enough to strike an arc, but not so high as to endanger the welding operator, for example, for a 2000A transformer the OCV should not be over 90 volts through for lower currents of say upto 600A OCV may be upto 100 volts.
  • With direct current, the OCV must be at least 30 to 35 volts while with alternating current it should not be lower than 50 to 55 volts. An open welding arc can be sustained at 18 to 40 volts.
  • The minimum voltage for arc ignition is 25 volts which must be attained within 0.05 second for the maintenance of a stable arc.

The Origins & Process of Arc Welding

This process was apparently developed first in the 1880's, but it was not perfected until many years later. The parts to be welded are connected to one terminal of an electric circuit, and a rod called an electrode is connected to the other terminal.

The electrode is usually made of metal that has about the same composition as the workpiece and is called filler metal because it melts and fills the joint. An arc is created when the electrode is touched to the workpiece and slightly withdrawn. An arc is like a miniature lightning bolt. It occurs because the two ends of the electrical circuit are close enough for the current to jump the gap.

Thursday, August 21, 2014

A Brief Summary on Submerged Arc Welding Process and SAW Wires

SAW also referred as Submerged Arc Welding or Submerged Arc Welded Tubulars is a welding process wherein the metals are joined by generating heat with arcs or an arc between the work surface and the bare metal electrode. In all major welding process a shield is provided to protect the welding, same applies in SAW welding in which the shield is provided by a blanket of granular fusible material on the work. No pressure is used in this welding process and filler metal required for welding is obtained from the supplementary welding rod or the bare metal electrode. These welding rods or bare metal electrodes are termed as SAW wires. These wires are available in both copper coated and stainless steel format.

The Art of Arc Welding

Welding is used as a fabrication process in every small and large-scale industry. This is an efficient, economical and dependable process of joining two or more parts of metal.  The process finds its applications in open air, underwater and outer space.

Among the welding processes, arc welding is widely used mainly because of its low capital and running costs.  Arc welding is the fusion of two pieces of metal by an electric arc between the pieces being joined – the work pieces – and an electrode that is guided along the joint between the pieces.

The four types of arc welding are shielded metal arc welding, gas metal arc welding, flux-cored arc welding, and submerged arc welding.

Submerged Arc Welding Basic Knowledge

Submerged Arc Welding

Submerged Arc Welding, often abbreviated SAW, is a specific and popular type of arc welding where the area being melted and welded is covered by a blanket of flux. This provides welders with several advantages, from reducing UV radiation to providing a higher quality weld. Traditional arc welding uses an electric current to create an arc of electricity between an electrode and the metal being welded. This electrical arc melts and joins the materials together, and the electricity can be provided by either a direct current (DC) or alternating current (AC).