Safety Procedures and Applications – CHWELD

Q: What are the ways to avoid electrical shocks?
A: When you are under a wet working conditions. If you must work in a damp area, always wear rubber boots and gloves. This amount of voltage can cause extreme shock to the body and possible death. One should abide to the following rules:
• Keep your welding machine dry.
• Always ground your welding machines
• Never install higher amperage than recommended or specified.
• Install electrical components in compliance with all codes and standards
• Never open a welding machine’s cover or cabinet when it is operating or closed circuit.

Note: Water is an excellent conductor and electricity will always run through the path with least resistance. Poor connections and bare spots/broken insulator on cables further increase the possibility of electrical shock, and therefore, daily inspection of these items is recommended. Equipment operators should also routinely inspect for proper ground connections.

Q: How can I inspect and maintain my CO2/MAG wire feeder?
A: Periodically inspect of the electrode wire drives rollers. . If unclean or dirty, remove the drive rolls with a wire brush. Deformed drive rolls should be replaced. Cleaned and remove the wire rolls only when the wire feeder is shut off. Remember that when power is applied to a wire feeder, always keep your fingers off the drive roll area.

• Clean the grease and welding spatter in the grooves of the feeding rollers.
• Check and remove metal filing from the rollers
• Check whether is there any overheating of the cable joint.
• Check the inlet and outlet guides and replace the deformed from wire wear

Q: What are some important electrode safety considerations?
A: Welding power sources for use with MIG and TIG welding, if the electrode becomes electrically hot when the power source switch is ON and the welding gun switch is closed. Always avoid touching the electrode wire or any conducting objects in contact with the electrode circuit, unless the welding power source is off.

GMAW

Q: What are the advantages of GMAW (MIG) welding?
A: It's easy to learn how to GMAW (MIG) welding machines which only require a little practice from the trainer; even a first-time user can achieve a good-looking weld

• GMAW (MIG) welding is a much faster process than Stick welding, with the wire feeder increase productivity minimum of   40% basing on the man- hour.
• The operating cost of GMAW (MIG) welding is lower compare to Stick Welding (SMAW) because of the time savings and   virtually no waste of filler metals, the deposition of filling is almost 95% than to stick welding (SMAW) where as much as   25% of each electrode is discarded as stubs.
• GMAW (MIG) can weld thinner materials and easier with MIG than Stick welding
• GMAW (MIG) welding is a cleaner process and does not require chipping slag off the weld as compare to Stick Welding.   (SMAW)

Q: What are the disadvantages of GMAW (MIG) welding?
A: Initially, to set up a MIG (GMAW) system is much more expensive compare to Stick Welding (SMAW) due to the requirement of regulators and shielding gas. In- term of costs per amp, Stick welding is less expensive.

Note: Some MIG welding is done with self-shielding flux core which does not require gas or a regulator.

Q: What types of material can be welded with MIG machines?
A: Virtually all types of material can be welded with a MIG machine. MIG (GMAW) process different materials require different wire and gases. Example: mild steel can be welded with either self-shielded wire, (which does not require separate shielding gas) or with CO2 or a CO2 mixed gas. Aluminum material requires the use of Argon gas.

Q: What is the difference between a constant speed wire feeder and voltage sensing wire feeder?
A: Wire feeders come in two categories:
• Constant Speed or Voltage Sensing. A constant speed wire feeder is used with a CV power source. Voltage is set at the   power source, while the wire feed speed (which controls amperage) is set at the constant speed feeder. A voltage   sensing wire feeder (sometimes called voltage following or variable speed) can be paired with either a CC or a CV power   source.
• When a voltage sensing wire feeder is paired with CC power source, amperage is adjusted at the power source and   voltage varies directly with the distance (arc length) between the electrode and the work piece.

Stick Welding Q & A

Q: What are the advantages of Stick welding?
A: SMAW initial investment in equipment is low or less expensive. With Stick Welding you get more amps per dollar compared to MIG (GMAW) welding. Do not require regulator and mixed gases.

Q: What are the disadvantages of Stick welding/ electrode?
Stick welding/electrode welding is a slower process compare to MIG welding. (GMAW) The Stick process can only weld on thick material, it can easily burn through a thin metal plate, and it cannot be used to weld thin material. Require cleaning slag off the weld which is a messy and time-consuming job. The operating cost of Stick welding is higher than MIG welding because Stick welding doesn't have as good of a deposition rate. For example, 100 lbs. of Stick electrodes yield approximately 60 lbs. of deposition MIG (SMAW) as compared to 100lbs yielding of 95 lbs. of deposition.

Q: What types of material can be welded with a Stick machines?
A: All common materials can be welded with a Stick machine (SMAW), selecting the right or appropriate stick electrode for the material being welded. Note: Material thickness depends on the particular diameter of the electrode rod selected to weld. (Electrode sizes: 1.2, 2.4, 3.2, 4.0, 5.0 etc)

Q: Can a Stick machine weld through dirty materials?
A: To have a best result with good finishing, it is advisable to weld on the clean material. Require to scrape off paint, rust or other debris before welding on a dirty material.

Q: When Stick welding, is there any advantage to welding DC versus AC?
The advantages are as follows:
• Easier out-of-position welding
• With easier starts
• Less arc outages and sticking
• Less spatter ( better looking welds and better result)
• Easier for novice/ trainee to learn, how to weld in DC mode than in AC
• Easier to welds thinner materials
• Smoother arc

Q: Can some wire feeders provide pulsed-MIG capabilities?
A: In addition to conventional MIG, some wire feeders, like CHWELD MIG 500 with Pulse with an inverter-based power source ( the micro- processor- One or more integrated circuits that can be programmed with stored instructions to perform a variety of functions) allows users to use the factory-set programs and create a finely-tailored pulsed-MIG arc without separate pulsing controls. Using the wire feeders, the welding technicians can adjust 4 major characteristics of the CHWELD MIG 500 with Pulse: the pulsed arc wave form - peak current, background current, pulse time, and pulse frequency - to optimize it for specific applications or welding positions. It is important when choosing the right or compatible wire feeder.

Note: A modified spray transfer process that produces no spatter because the wire does not touch the weld puddle. Applications best suited for pulsed MIG are those currently using the short circuit transfer method for welding steel, 14 gauges (1.8 mm) and up. Consumables: contact tips, shielding gas, welding wire.

Q: How do I determine when to use TIG vs. Stick or MIG?
A: Require better appearance and visible for consumable goods, it is recommended for manufacturer to use TIG (GTAW). For stronger welding, you can use TIG (GTAW)/ MIG (GMAW) Example: those require stronger or comply with the welding procedures or code requirements. Such as work, piping, pipe joining, and high profile consumer goods which require at least the root pass. Depending upon quality and the welding procedures (code requirement)

In pipe joining fabricators or other critical cases which require strong bonding with multi-pass pipe weld may have to be done with TIG (GTAW) and followed by X-ray.

Works that is not stringent which do not need "X-ray". MIG welding (GMAW) may be the best choice. MIG is not a "poor quality" welding process; it is generally accepted in the welding industry when X-ray is not required.

Q: When selecting TIG equipment, what should I look for?
A: Determined how much power and sophistication are required for the job, the costs factors, and need to anticipate what might be welded in the future. Also need to consider the scale of the job that requires high duty cycle units. An industrial power source is also required or extremely low amperages, such as welding wafer-thin below at three amps.

Q: Do I need an AC/DC power source?
A: Direct Current Electrode Negative (DCEN)-The specific direction of current flow through a welding circuit when the electrode lead is connected to the negative terminal and the work lead is connected to the positive terminal of a DC welding machine. Also called direct current, straight polarity. (DCSP). A general rule would be: If your application is strictly TIG, get a TlG only machine. Get a combination CC/CV only if you are sure you want to do MIG or flux-cored welding along with TIG. Direct Current Electrode Positive, (DCEP) The specific direction of current flow through a welding circuit when the electrode lead is connected to a positive terminal and the work lead is connected to a negative terminal to a DC welding machine. Also called direct current, reverse polarity (DCRP).

Two common metals such as aluminum and magnesium that are best welded using the AC output from the power source. Steels and stainless steels are most often welded with DC output. To weld a variety of metals, use a combination AC/DC machine.

Q: Why is welding power source duty cycle important?
A: The duty cycle of a welding power source is the amount of time you can weld at a given output without having to worry about overheating or burning up the power source. The number of minutes out of a 10-minute time period an arc welding machine can be operated at maximum rated output. An example would be 60% duty cycle at 300 amps. This would mean that at 300 amps the welding machine can be used for 6 minutes and then must be allowed to cool with the fan motor running for 4 minutes. For the remaining four minutes the Power source needs to idle and cool. The duty cycle for many machines goes up as the amperage goes down.

Welding Application Q & A

Q: How do I know what amount of shielding gas I need for welding steel and aluminum?
A: Shielding Gas-Protective gas used to prevent atmospheric contamination, 15 to 25 CFH is the normal flow rate. If you are working in an area where there is little or no air movement, this is usually enough. More than normal air movement can require 20 to 25 CFH.

Q: How do I decide which MIG machine to buy?
A: MIG (GMAW) is an arc welding process which joins metals by heating them with an arc. The arc is between a continuously fed filler metal (consumable) electrode and the work piece. Externally supplied gas or gas mixtures provide shielding. Common MIG welding is also referred to as short circuit transfer. Metal is deposited only when the wire actually touches the work. No metal is transferred across the arc. Another method of MIG welding, spray transfer moves a stream of tiny molten droplets across the arc from the electrode to the weld puddle. Consumables: contact tips, shielding gas, welding wire.

Require determining the thickness of the material to be welded. The maximum thickness will also determine how much amperage you need. For example, 3/16 inch metal needs 130 amps; 1/4 inch metal needs 150 amps; 5/16 inch metal needs 170 amps; 3/8 inch metal needs 185 amps; and 1/2 inch metal needs 250 amps.

Q: How do I decide which plasma cutter to buy?
A: Plasma Arc Cutting. Determined and anticipates the maximum thickness you will need to cut for your future usage. .An arc cutting process which severs metal by using a constricted arc to melt a small area of the work. This process can cut all metals that conduct electricity. Cutters are complete packages that contain all required equipment and torch consumables. Consumables: torch consumables, gas or compressed air supply.