Welding polyurethane foam-filled parts can produce toxic gases. Welding should not be attempted on parts filled with polyurethane foam. If repair by welding is necessary, the foam must be removed from the heat-affected area, including the residue, prior to welding.

 This is a hazardous procedure. The hazard to the worker is due to the toxic gases generated by the thermal breakdown of the polurethane foam. The gases that eveolve from the buring foam depend on the amount of oxygen available. Combustion products of poplyurethane foam in a clean, hot fire with monoxide and traces of hydrogen cyanide.

Remember - all residue must be cleaned from the metal prior to welding.

In order for welding to be fully accepted as a tool in engineering, the passing of information from the architect of the design and the end user must be accurate and fully understood. One way of doing this is by using widely accepted welding symbols which enable design drawings to be completed with welding information. The most common method used in the USA is the “third angle” method of projection.

The main reference used for welding symbols is the joint. The joint is used to designate the type of weld to be made, its location, contour, extent, dimensiuons and other additional information. Any joint that is welded is indicated by a symbol and will have an arrow side and an other side.

The tail of the symbol is used for designating the welding and cutting processes as well as the welding specifications, procedures or the supplementary information to be used in making the weld. If a welder knows the size and type of weld, he only has part of the information necessary for making the weld. The process, identification or filler metal that is to be used, whether or not peening or root chipping is required and other pertinent data must be related to the welder.

There are three basic welding methods: manual, semiautomatic, and automatic. Manual welding is the oldest method, and though its proportion of the total welding market diminishes yearly, it is still the most common. Here an operator takes an electrode, clamped in a hand-held electrode holder, and manually guides the electrode along the joint as the weld is made. Usually the electrode is consumable; as the tip is consumed, the operator manually adjusts the position of the electrode to maintain a constant arc length.Semiautomatic welding is becoming the most popular welding method. The electrode is usually a long length of small-diameter bare wire, usually in coil form, which the welding operator manually positions and advances along the weld joint. The consumable electrode is normally motor-driven at a pre selected speed through the nozzle of a hand-held welding gun or torch.Automatic welding is very similar to semiautomatic welding, except that the electrode is automatically positioned and advanced along the prescribed weld joint. Either the work may advance below the welding head or the mechanized head may move along the weld joint.There are, in addition to the three basic welding methods, many welding processes which may be common to one or more of these methods.

Altogether, there are approximately 100 types of welding. When you learn to weld, you will learn the differences among them. Differences are due to the molecular nature of the materials, required precision, and environment in which the welding takes place. For example, a sculptor might use a gas flame to weld two pieces of metal in an open-air setting, while an astronaut might use an electron beam to weld thermoplastics when working on a satellite in space.

The purpose of this article is to introduce the welding beginner to the equipment used in the Oxy-Acetylene welding process. This will be done starting with the cylinders and ending with the torch tip.

The use of gas welding dates back to the middle 1800’s where a mixture of Oxygen And Hydrogen were used to produce a hot flame that was used in the making of jewelry. It wasn’t until the late 1890’s when the gas Acetylene became available that gas welding developed into the process that we know today. Acetylene is a gas that is manufactured by mixing Calcium Carbide,( a by product of the electric furnace steel making process) with water. Acetylene when burned alone can produce a flame temperature of about 4000 deg. F. With the addition of Oxygen a flame temperature in excess of 6000 deg. F. can be achieved, making Acetylene ideal for welding and cutting. An Oxy-Acetylene outfit is portable, less expensive and more versatile than a electric welding set up. By using the proper tips, rods and fluxes, almost any metal can be welded, heated or cut using the Oxy-Acetylene process.

Welcome to my welding blog. Here you will learn to weld like a pro through the welding information and welding articles I will provide for you. And remember, you can learn to weld like a pro within a short time with welding secrets.