Pipe Welding: Three Commonly Used Processes

Nov 2014 03
16 27 Mon
Written by Alexander Barth

Pipe welding is an important trade which has revolutionized modern society. There are several different categories including pulsed TIG, stick and MIG welding. Of course, this skill takes a good amount of time to master and welders need to be certified based upon levels of expertise. In terms of pipeline welding and even domestic purposes, all welding processes need the use of electricity to generate the necessary heat to successfully bond two sections of pipe. Also, equipment such as pipe clamps and pipe stands are required to provide a safe and stable platform during the entire process. So, what are the basic forms of welding that are used?

Stick Welding:
As the name hints, this process involves a rod that is coated with a metal powder which acts as a shield from oxygen during the burn process. This is the most common type and it can be somewhat difficult because the welder is not able to see the weld due to the fact that it will be covered with slag. This excess material must be broken away after the weld is complete.

Metal Inert Gas (MIG) Welding:
This technique employs a wire spool which feeds this material to the intended pipe joint. Also, a pump supplies inert gas to the welding handle. This gas is again intended to protect the weld from any ambient air. While MIG welding is considered to be easier than stick welding, setting up the required pipe welding equipment can be difficult and due to the potential for windy conditions, this is generally not used for exterior tasks. (See more on MIG Welding Pipe)

Tungsten Inert Gas (TIG) Welding:
This method uses a torch which contains gas within its interior. A permanent tungsten rod heats the metal of the pipe while a "filler" metal is held in another hand. This metal is fed into the joint as is needed. The benefits here are that a greater degree of control can be enjoyed and the weld can immediately be seen. However, this two-hand process can be challenging for novices and TIG welding is therefore considered to be one of the most difficult forms to master. (See more on TIG Welding Pipe)

These are some of the most basic features of modern welding processes that are used. In many respects, welding is as much of an art form as it is a science. Experienced welders boast decades of experience in this novel, challenging and potentially lucrative industry.
 
Alexander Barth
 
For more information go to dwt-gmbh.de

Read More

GMAW or GTAW: How to Choose the Right Welding Process

Oct 2014 16
19 40 Thu
Written by Weld.com

There are a lot of different choices out there when it comes to welding. A lot of home hobbyists (or Weekend Warriors) have trouble deciding which process to use, especially guys that are new to welding. When it comes to welding in your garage or in home use, there are basically four processes that most welders consider these days; GMAW, GTAW, SMAW or FCAW. Each of these processes have advantages and disadvantages and should be considered for different reasons. GMAW and GTAW have become the two prominent choices for home use these days (see our video on the differences between MIG and TIG for more information). In this article, we will go over what you need to get started with each process and some reasons why you might choose one over the other.
 

Read More

MIG Guns: Choosing the Right Torch

Sep 2014 30
12 46 Tue
Written by Weld.com

When people buy a MIG welder, normally you will see them research, ask questions and test machines until they find one that fits their needs. It is a wonder of mine why people don’t go through the same steps when choosing a MIG gun (or torch). Think of it this way; you wouldn’t find the best doctor in the world to do a surgery and give him a rusty knife… The torch is a part of your welding system and should be treated as such when being selected. Different MIG guns are suited for different applications and there isn’t a “One Gun Fits All” scenario. Take a moment to read the next few paragraphs on choosing the right MIG gun for your project.
 
MIG Guns: An Assortment of Types & Styles

When people think of welding torches, they usually think air or water cooled. While this is a consideration you will want to make, there are many other choices when picking your MIG gun. We will look at some of the most common torches that will cover a vast majority of hobbyist needs:


Push-Pull: Push-pull guns are available in both air cooled and water cooled designs. These torches, although very expensive, are also perhaps the closest thing to the “One Gun Fits All” scenario. They are good option when accessibility to the weldments if difficult, as some guns can be used up to 50 feet away from the wire feeder! Push-pull guns are usually used to weld soft alloys; such as small diameter stainless, aluminum, silicon bronze and cored wires. It is important to make sure that the gun you are considering is compatible with your wire feeder. Since the feeder works in conjunction with the gun to feed wire, not all systems are interchangeable. Push-pull guns are typically available in gooseneck and pistol-style grip to meet application demands and operator preference.



Air Cooled: Air-cooled guns use air and shielding gas to cool the torch. The power cable on an air-cooled gun contains large amounts of copper to insure the cable insulation does not overheat and melt. For this reason, air cooled torches are generally heavier, less flexible and more difficult to maneuver than water cooled torches. On the other hand, while they do have more copper, they are actually less expensive because they do not have all the added expenses of water cooled torches (cooler, hoses, etc.). This, in addition to their simple design makes air cooled torches ideal for new welders getting started. Air-cooled MIG guns can be purchased in a variety of amperages, but in most cases the Weekend Warrior won’t need the higher amp torches.



Water Cooled: Water-cooled MIG gun systems use a water cooler that circulates water, ambient air and shielding gas to cool the gun. Water cooled torches (including accessories) will generally add approximately $1000.00 to your welding rig and are generally preferred when welding at high amps for long periods of time.



Spool Gun: Spool guns are unique in the way they feed wire. Generally, welders will use spool guns when feeding soft wire, especially Aluminum. These torches have a small spool of wire located on the rear of the (pistol shaped) gun. Since the wire is only being fed a short distance from the back of the gun (and not the whole way through the feeder) issues normally associated with soft wire (like bird nesting) are eliminated. Spool guns are ideal when welding with soft alloys for short amounts of time. If you plan on welding aluminum, the spool gun is a must have! If you use a push-pull gun for aluminum you are going to cause yourself a lot of headaches that could easily be avoided by grabbing one of these!



Fume Extraction Gun: Fume extraction guns have become more popular recently with safety becoming more important to welders. These guns capture smoke and fumes right at the gun and suck them back into a high-vacuum fume extraction system. Unfortunately, this means there is the added cost of purchasing a fume extractor if you don’t already have one. Typically rated between about 200 - 600 amps, these models have become smaller and user friendly recently with features such as adjustable extraction control (as seen in the image), smaller vacuum chambers, improved neck designs for better joint access and more flexible extraction cables.



Flux-Cored Guns: Most mig machines these days will run both solid and flux cored wire. Actually, a lot of machines are now coming pre-packages with flux cored guns (which can confuse a lot of newbies), so be careful when setting up your machine for the first time. The FCAW wires are usually rougher in the guns consumables, so it is important that you don’t put flux cored wire into a mig gun. If you plan on doing any FCAW (Flux Cored Arc Welding), make sure you get a flux-cored gun.

For more information on welding guns and torches, visit the welding forum.

Read More

Plasma Cutting: A Beginners Guide

Sep 2014 29
19 40 Mon
Written by Weld.com

Plasma cutting is a way of cutting through metal quickly and easily. Plasma cutters are quickly becoming the go to machines for home hobbyists, weekend warriors and small shops that need to cut metal on a budget. One of the major reasons for this is the price for these machines has dropped so much in recent years, making them affordable to almost everyone. So, are you in need of a plasma cutter? Well, if you are looking to supplement [or replace] a mechanical saw, taking on new projects that require more metal cutting or just think you want a cool new toy; you might think about a plasma cutter!

How does a plasma cutter work?
Plasma cutting is a fairly simple process that doesn't require much training. The way it works is the machine connects to an air compressor, which allows it to push out a stream of ionized gas through a constricting tip [via a torch]. This pressurized, ionized gas is also known as plasma. When using a plasma cutter, the plasma creates electricity, which is then transferred from the torch to the material you are trying to cut. In fact, when using this process, you are not technically "cutting" the metal, but melting it via a very fine orifice.

Read More