Posts Tagged ‘Aluminum Welding’

Angle of the Dangle: Resolving welding issues with torch angle adjustment

Thursday, October 27th, 2011

A new weldor can often be plagued with curious and aggravating weld issues that often lead to a great deal of frustration. Even occasionally it will occur with seasoned veterans of the welding field as well. Often times occurring after a long day of welding or when fatigue is likely to set in. These symptoms are not necessarily exclusive to only one type of weld process. They can occur while stick, mig, or tig welding when conditions are right. Symptoms can include inconsistent porosity issues, slag or silicone trapped in the toes of the weld, inconsistent weld bead formation, without fusing on both sides or piling of the weld on one side or the other, dirty looking welds or even large amounts of spatter.

All these issues can usually be traced to improper torch angle. A weldor has to monitor two angles of the torch position relative to the work surface and the weld.

1.  The torch angle relative to the direction of the weld. If TIG welding, particularly noticeable in aluminum, a steep angle greater than 15 degrees from vertical can result in a siphoning effect with the gas flow, pulling in air from behind the weld in to the molten puddle. Usually the angle should be with the torch reclining toward the weld area already welded, with the tungsten pointed toward the front edge of the puddle. Also, the arc can be projected too far forward creating instability issues. The weldor can suffer similar issues while welding MIG as well. However, the torch can be pointed either in the pushing or pulling direction. Whether a forward or rear leaning approach is taken, the penetration and weld width will change. While stick welding too great of an angle causes multiple symptoms, including porosity, and weld rolling into the toes of the weld. In general the torch angle should “lead” the weld, and the torch should seem to be dragging the weld along. Again the 15 degree rule should apply.

2.  The angle relative to the sides of the weld should be monitored as well. This second plane is responsible for even distribution of the heat. Improper fusion of the weld will result or overheating of one side of the metal can be seen by following the heat lines. This angle can be manipulated however, to join dissimilar thicknesses by focusing more heat on the thicker material. However, when joining the same thickness of material the torch should be held vertical as possible to the weld with the torch/electrode even distanced from either side of the weld. This applies to TIG, MIG and Stick processes of welding.

As a new weldor, if you suspect you are seeing transient problems, inspect your torch angle. Many problems can be solved by concentrating on the torch angle. If they don’t resolve, then you should proceed to suspecting other causes of the problem such as contaminated gas, or dirty metal, or insufficient gas flow.

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Polarity: When should it be reversed? Part 2

Wednesday, October 12th, 2011

Using correct polarity makes the difference between a quality weld, and one that is porous and weak, or one that gets proper penetration, or one that barely gets any at all. Beyond the confusion of the terms, it is often confusing to know just when to use what polarity.

While stick (SMAW) welding, the great majority of welding rods require a positive polarity. In fact nearly all welding rods run primarily with positive, (reverse) polarity. With a few exceptions, in the case of running on thin sheet metal, you should always run with reverse polarity.  Since the term “Reverse” may be confusing, just always think “positive torch” and you should be ok. MIG welding is always going to be positive polarity. Some people confuse MIG with flux core welding.  They are not the same, though the equipment used can be nearly the same or identical. Flux core uses a wire that contains a powder flux in the center of the wire. It has its advantages in windy conditions, and offers go anywhere performance. While not necessarily better or worse than the MIG process, it does utilize straight polarity, just the opposite of MIG. There may be some wire manufacturers however that recommend positive polarity, so be sure to check the label. One thing to note, MIG and Flux Core wire do not have “optional” polarity with the same wire. If its positive, it will only run successfully on positive. Dual shield wire utilizes the best of MIG and Flux Core by using a flux wire and shielding gas. Always follow the polarity recommendation of the wire manufacturer of course, but generally dual, or outer shield wire uses reverse polarity.

TIG is the exception and is the process where it will always weld with the torch in the negative terminal (even if welding in AC mode there are reasons to keep the torch plugged into the negative side). Years ago, DC positive was used for welding aluminum, but penetration was very poor, and it required enormous diameter tungsten to weld at relatively low amps due to heat being maximized on the tungsten tip instead of the base metal.  Since aluminum welding is so easily accomplished with AC tig units with either high frequency overlay or inverter style welders such as the Everlast PowerTIG series,  DC negative torch polarity is the only one used.

Whatever the polarity, you may need to employ some sort of memory device to help you remember the polarity terms. Even if you have to write a note on your welder to help you remember the “torch” side that you will use, it will help you in get it right, and keep frustration down to a minimum.

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Choosing the right electrode for welding

Thursday, April 28th, 2011

There are many factors that you should consider before you choose the right electrode for welding. First you should consider the type of metals that are being used. You cannot universally use the same electrode for every metal you weld together.

What you use for aluminum and brass will not be the same as you use for steel. Next is the resistance to corrosion by the electrodes. This is an important property for the storage of electrodes. If you are buying electrodes in a bulk for the use of a long term project, you should defiantly keep this factor in mind. Next is the type of coatings that these electrodes would carry.

Electrodes may be consumable or non consumable. A consumable electrode may melt during the welding process and add to the strength of the weld. Therefore it would depend on the type of welding process you are using to join two metals.

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Welding As a Part Time Job

Wednesday, February 16th, 2011

Welding business is one of the mechanical industries which are always in need of skilled craftsmen. While doing a welding course in one of the welding schools in USA to end up in a reputed manufacturing company as a welder can be considered an option.

On the other hand, if you are passionate about welding and know the basics of it but due to unavoidable circumstances you shifted to another industry. There can still be hope for you to do what you are passionate about and even those who studied welding but had to move on, you have a set of skills that can help you make business.

The initial thing to do would be to do some small welding jobs that impress your surroundings, who would consider you as an option to satisfy their welding needs. Try to popularize yourself, use the internet as a tool and showcase your skills and also make sure you specify your locality. People who are searching for welders in your locality could actually contact you. Just try to keep improving your welding skills and also if you are a skilled craftsman people would let you specify your timings and you could actually make a lot out of your welding skills.

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A note on Aluminum welding:

Thursday, November 11th, 2010

Welding aluminum can be done either with a wire feed welder or stick machine. All the general welding safety rules apply, and follow them can avoid dangerous accidents.

• Wear protective welding hood while welding aluminum. UV rays can be very harmful to eyes.

• Always wear welding gloves, long jeans, boots and welding jackets so that welders can protect their body from sparks and heat caused by welding.

• Always route the welding leads and cables from the welder to the steel so that nobody can trip on them.

• Always turn the welder off and put cords and leads safely away after welding aluminum. Clean up any tools and materials used in the project so they don’t become a hazard.

• Before inspecting the machine make sure that all the cords and welding leads are free of defects and that no bare wire is showing before welding aluminum.

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A View On Aluminum Welding:

Monday, October 25th, 2010

Welding of aluminum can turn out to be as a tricky task and it is usually saved for professionals. To learn the process and proper techniques of weld by following safety precautions it will usually take lot of your time. After learning the process of aluminum welding you can conduct this activity on your own.

While performing the task of aluminum welding you must check the surroundings of your work environment. Be away from electrical wires or outlets and keep your environment well ventilated. In addition to this one important point you must remember is, to perform the task by wearing gloves, welding helmet and by following other safety measures too. Do remember that your head should always be away from any fumes, even when you have worn a weld helmet.

Clean the aluminum that you are going to weld. Spray off the surface of aluminum with the help of electrical cleaner and then rinse it off with clean water. Dry up the metal once the dirt is clear. At the time of aluminum welding remember that this is the area where you are going to compress the pieces so as to prevent them from wrapping.

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How to protect yourself while welding Aluminum:

Friday, October 22nd, 2010

You can weld aluminum either with the help of wire feed welder or a stick machine. If you don’t follow safety rules it can lead to dangerous accidents.

• Always wear a protective welding hood when aluminum welding. Ultra violet rays created in welding process are very harmful to the eyes.

• While welding it is important that you wear thick leather welding gloves, long jeans, boots and a welding jacket to protect yourself against sparks and heat caused by welding.

• Clean the work area if there are any flammable items such as rags.

• Inspect the machine to ensure that all the cords and welding leads are free of defects and that no bare wire is showing before welding aluminum.

• Always turn the welder off and put the cords and leads safely away after welding aluminum. Clean up any tools and materials used in the project so they don’t become a hazard.

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Techniques of welding aluminum:

Thursday, September 30th, 2010

Aluminum welding is easier than welding steel. Several methods are used in joining aluminum via welding: mig welding, tig welding and using a stick electrode. MIG welding is a process that will require some post-weld touchups for a presentable finish. Mig welding uses an electrode of continually fed wire forming the base of the welds, which is also shielded by an inert gas or gas mixture. While using aluminum for mig welding, it is considered somewhat messy because you’ll need to use the spray transfer method in which the arc creates a spray of tiny metal beads.

TIG Welding does not require must post-weld clean up and finishing, and is therefore ideally suited to quick and easy welding of aluminum. Rather than using a fed-wire electrode, tig welding uses a permanent tungsten electrode that is not consumed by the welding process. You have to add any filler metal manually, making this process best suited to joints that can be achieved without additional metal.

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Everything you ought to know as to how to weld Aluminum:

Friday, September 24th, 2010

Safety First:

When welding aluminum, wear all needed safety equipments. You should wear gloves, goggles, hearing protection and a heavy apron so that you can protect your body from spatters. Wear eye protection equipment to protect your eyes from ultraviolet rays. Make sure your work area is well ventilated so that fumes can be removed when welding. For precaution purpose, keep your face away from fumes as far as possible.

Material preparation:

• Clean away all the lubricants.
• Remove aluminum oxide from the surface of the metal with the help of a metal brush.
• Do not use a brush that is used in other materials.
• While pre-heating is not compulsory, if you’re welding two pieces of different gauge aluminum, pre-heating can help prevent some problems.
• While pre-heating aluminum, it should not exceed 230 degrees F.

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How to weld aluminum in a safe way:

Monday, August 30th, 2010

Aluminum can be welded either with a wire feed welder or stick welding. To avoid injury, use these safety measures:

• Wear a protective welding hood while welding aluminum.

• It is important that you wear safety equipments like thick leather welding gloves, long jeans and boots and welding jacket to protect yourself against sparks and heat caused by welding.

• After welding work is over for the day, clean the work area as it can reduce the risk of fire caused by sparks.

• Always route the welding leads from welder to steel so that nobody can trip on them.

• Before a technician starts the aluminum welding process, ensure that all the cords and welding leads are free from defects.

• After welding work is over, turn off the welder.

• Clean up all the tools and materials used in this project so they don’t become a hazard.

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