Oxy-Acetylene Welding

Oxy-Acetylene Welding is the welding process of heating two pieces of metal to melting point, bringing the parts together and while still in a molten stage hammered together to form a joint. Learning how to weld using this process will give a complete overview of welding.

The Oxy-Acetylene Welding process requires the use of a special welding torch that mixes oxygen and acetylene gasses that can produce a small intense flame heat of up to 6300 degrees. This temperature is more than twice the melting point of most metals.

This process has been widely used in the past for the manufacture of wrought iron projects such as iron gates and fences. These methods have widely been superseded by the introduction of electric arc welding.

Today Oxy acetylene welding is generally restricted to industries that work with copper pipe and the joining of copper and brass. Other specialized applications include such as building up of brass wear plates and the welding of cast iron housings that may be cracked using brass or bronze rods as a filler.

Gas Cutting Using Oxy-Acetylene.

Most gas torches include a function for gas cutting. This is in the form of a lever style valve that allows an extra burst of oxygen through the cutting torch to the work that has been heated to melting point.
This injection of oxygen to the work causes the parent metal to burn away with great force and speed, producing a small narrow cut in the metal.

Using this method has allowed metals to be cut easily either manually or by machines called profile cutters. Gas cutting manually can easily cut metals of 1/16 of an inch and up to two inches where as profile cutting can cut steels up to four inches thick.

Many profile cutting machines now use LPG gas instead of acetylene as the flame and cut produced is cleaner. Propane torches for auto and manual cutting are constructed differently to acetylene torches and also require different cutting tips

Welding Rods

When choosing welding rods try to avoid buying inferior quality as the better your grade of material in the welding rod the better the end result will be.

Your welding rod is used to lay over additional metal to the weld therefore it needs to match the parent metal. If the metals are dissimilar then best efforts to locate a filler rod comprising of a composition of the two metals. For example if welding manganese, or nickel specific welding rods of specific alloys are recommended.

Welding wire and Oxy-Acetylene Welding rods are most always of Norway steel. This grade is most pure and gives a sound soft weld especially suited to machining if required. When welding aluminium the proper rod is most important as aluminium is difficult to weld and requires alloyed rods to ensure even flowing.

Arc Welding Basics

Arc welding is considered the easiest and most readily available of all the welding processes. Nearly everyone can gain access to an arc welding machine and learn how to arc weld. Also known as stick welding,  the technical name for this type of welding is manual metal arc welding or otherwise, MMAW.

arc weldingArc welding is used in all fields of metalworking and engineering for both fabrication work and maintenance. Metals that can be welded include mild steel in thicknesses from 1/16th up to 2 inches, stainless steel, and cast iron. Arc welding is an excellent method of repair work to cast iron castings.

During the arc welding process is that the arc generates enough sustainable high intensity heat to melt the intended metal at any point it is directed to. Combined with the filler / electrode this action effectively fuses two pieces together.

Choosing an Arc Welder

For general purpose use a welding machine with an AC/DC output is ideal. Using the DC output will give better results as this setting allows easy starts with less sticking. Other advantages using DC settings include easier overhead and vertical welding, less cleanup due to splatter and good looking welds.

As far as power goes the more power you can afford the better. Having said that most arc welding applications can be handled using a machine of 225 Amps. However a machine that has a lower amp rating can still be used to weld say 1 inch steel by making several passes of weld to build up the required bead size.

Since there is a serious shortage of reliable welders to draw from and the demand is increasing daily, you can understand why knowing that welding is not difficult to master is an important thing to know. It is estimated that approximately 80% of all American companies that hire arc welders find it hard to fill vacancies as they come open. It has also been reported that the average age of qualified and professional welders is 54 years. That is a high rate considering that those individuals will be retiring soon. It seems that the field of welding is one of the nation’s best kept secrets when it comes to getting ready for employment in the future.

Many people consider arc welding to be a dangerous occupation because of the electrical currents from high voltage that are used. In the past this may have been true, but today’s advancements in safety equipment and regulations the risk has been reduced by a large amount. Today, arc welding is not any more dangerous than working with plumbing and carpentry. Maybe it is time to get started with a whole new career.

 


Arc Welding Cast Iron

With no two pieces of cast iron being the same there are obvious challenges to arc welding cast iron. Most cast iron welding is due to maintenance and cracked casting repairs. The main two methods of welding cast iron is by using oxy acetylene welding processes or using stick / arc welders.

welding cast ironCast iron may be welded using a covered steel electrode, however this technique ought to be applied as an emergency solution solely. Whenever using any steel electrode, a contraction with the steel weld material, any carbon acquired in the cast iron from the weld metal, and also the hardness in the weld metal due to quick cooling down has to be considered. Steel shrinks a lot more than cast iron if ceded from the molten into a solid condition.

Each time a steel electrode is employed, that unequal shrinking can cause stresses in the joint following welding. Whenever a great quantity of filler metal is used on the joints, the actual cast iron may possibly fracture just back from the line of fusion unless of course precautionary measures are undertaken. To beat a lot of these complications, the prepared joints ought to be welded by way of depositing any weld metal in small stringed beads, 0.70 to 1.0 in. long (20.0 to 25.5 millimeters).

These are typically made sporadically and, in some instances, with the back-step and skip method. To help prevent hard spots, your arc ought to be struck in the V, rather than on the surface area on the base metal. Every brief length of weld metal employed on any joints ought to be carefully peened whilst hot using a modest ball peen hammer, plus permitted to cool prior to further weld metal being applied. This peening activity forges the actual metal and also minimizes any cooling down strains.

Cooling can also be assisted by covering the casting with a specialized cooling blanket or by covering the casting with sand. Arc welding cast iron is a slow process relying on diligent peening and cooling processes.

How To Weld Processes

So start to learn how to weld there are several questions that need to be addressed. To begin we need to determine what metals or alloys we intend to weld and then we are to choose the process and welding machine to use with that process. here we offer a brief description of the main welding processes and the welding equipment we will need.

For the welding of mild steel, stainless steel and aluminum we can choose from three main processes. Arc welding, MIG welding and TIG welding.

Arc welding uses welding rods or welding electrodes as a means of joining metals. This is the most simple and most likely cheapest way to learn how to weld. Arc welding machines are readily available either new or second hand and are most suited for welding mild steel and stainless steel in thicknesses of 1/8th inch and upwards.

Mig welding and MIG welding machines would have to be the most versatile and easiest of the how to weld procedures to master. No need to change electrodes as the machine operates with a wire feed system and employs a spool of welding wire within the machine. Great for welding both sheet metals and heavier steels. Can be used for welding mild steel, stainless steel and aluminum. Great for welding thin metal like on motor vehicle body-work.

mig weldsMig welders generally use shielding gasses s part of the process that can be limiting in outdoor welding applications, however there are gasless welding wires on the market suitable for welding mild steel. Having a small portable mig welding machine that uses gas free welding wire is a most versatile welding machine.

how to tig weldTig welding is a high tech approach to welding. This process takes time to master but will provide the best quality weld for small intricate jobs. Can be used with stainless steel, mild steel and aluminum welding. Tig welding can also be used for many exotic and specialized metals such as gold.

Tig welder machines can be small and compact such as the ‘caddy’ welders that are also capable of stick or arc welding. These machines are often seen on work sites and used by maintenance crews. A most versatile welding machine.

 

MIG Welding Basics

MIG welding stands for metal inert gas welding. It was originally used to weld non-ferrous metals such as aluminum. It eventually was used on steel too. It is a quicker method of welding as compared to other methods of welding.

mig weldingSome of the advantages of MIG welding include the speed of the welding process. It has the ability to weld many metals and many thicknesses of metal. The biggest advantage to MIG welding is that it can be automated so that the human element can be removed all together. That’s why robotic mig welders are commonly found is on an assembly line in an automobile factory. As mig welding machines utilize a wire feed system this makes them ideal for robotic purposes as they can carry a great amount of filler rod or wire.

Mig welding utilizes a wire feed technique which feeds a wire electrode from your welding handgun to the weld. This wire electrode is available in numerous coil capacities or spools dependent upon the welder sizing, that may contain 100s and perhaps 1000s of feet/meters of wire. The actual wire feed includes a pair of drive wheels to the wire plus a continual speed electric motor to move the drive wheels. The majority of Welders contain numerous features enabling timed feeds together with adjustable speeds.

You need the right safety gear. This includes a face mask to protect your eyes and skin. You also need to have a heavy leather jacket. Keep the jacket fastened all the way up. You need to wear heavy cotton pants and close toed shoes. Heavy work boots are best. Make sure that you are welding in a well ventilated area, and that you have some kind of barrier between you and others, and you have a warning sign that advises people to avoid the area.

When you start welding you need to make sure that you have the valve on the machine for the shielding gas is open. Your welding machine needs to be on, and the grounding clamp either on the metal or on your welding table.  Make sure that your metal is clean and sharp edges are ground down. Clean edges make your welds better. You can bevel the edges to create a valley for the weld if you choose to, this is more important on thicker metals.

After you have done that and set your machine up, it’s time to start welding. You want to make a zig zag or concentric circles with the tip. It’s smart to practice before you start welding. Make sure the mig welding machine is at the right setting. If you are getting holes in your workpiece your setting is too high. Your settings are too low if your welds are being formed in spurts. You have the right settings when your bead is nice and smooth.