Why Are Some Joints Back Gouged?
Back gouging is done to assure full complete joint fusion at the root and eliminate root pass discontinuities.
Back gouging is the smoothing, leveling, and re-applying of weld metal to the root of a joint, which is the area where the weld metal makes contact with the butt joint.
With back gouging techniques, you can produce a more uniform coating. Your coatings will be much smoother for grinding or painting.
With these coatings, you can run into fewer problems such as porosity from poor fume extraction or lack of gas coverage.
Why Does My Weld Have Undercut?
Excessive heat input or improper travel speed are the main reasons for experiencing an undercut. The lack of fusion may be at the start, middle, or end of a weld. It is the result of poor fume extraction and lack of gas coverage.
Undercuts are weld flaws that occur at any place other than the bottom center of a joint and are noticeable by a notched or rough weld bead, which is caused by the flow of molten metal externally into the bottom of a joint.
Another common way to see an undercut is by looking at your weld from the side, and if you see a slight dip in the middle then that’s an indication that something isn’t quite right. This dip will appear both on horizontal and vertical welds.
Can Too Much Gas Cause Porosity?
Yes, excessive gas flow can cause porosity, by moving air and moisture into the weld (air in/out of the molten pool) like a blow torch does. Inflating the fume from a torch can cause your weld’s porosity.
If you want to improve your weld quality, it helps to maintain proper shielding gas flow; this will allow more clean shielding gas to be pulled out of the molten pool and through to the workpiece.
Porosity occurs when sufficient heat is being generated to start the full fusion process. This will get your welding up to the proper temperature needed for welding. Your work piece needs to be hot enough for proper fusion and adequate penetration.
If you are having problems with porosity then make sure that you’re welding in the correct position and that you’re feeding proper amount of shielding gas into the pool for proper fume extraction, and check your torch settings for excessive spatter.
Why Do I Keep Getting Porosity In My Welds?
Porosity in your welds arises due to leaks in the gas line and hence a high gas flow rate which results in a lot of turbulence in weld pool.
As you are welding, you might notice a sudden outflow of gas. This can cause air to be sucked into the weld and cause porosity if there is not enough shielding gas available.
The best bet is to check your connections and replace any bad hoses or fittings. You can do this by using soap or bubble solution to check for leaks by spraying down the connections or hose and seeing whether it blows bubbles or starts to foam up.
Heat input can also cause oxides and contamination on the weld pool.
If you’re not sure about your heat input then make sure you keep track of it with a welding indicator. Otherwise, get a heat input gauge so you can adjust your settings to minimize risk of porosity in your welds.
Can You Weld Out Porosity?
Yes. You can weld out porosity by removing the porous section down to base material. If the porosity is small, you can grind out the area with a grinder and re-weld that area. If the porosity is large, then it’s often best to grind out the whole area and start fresh.
Before grinding out and re-welding a porous section, you should ensure that you are 100% sure of what caused it. Checking your shielding gas flow rate could be an indication of porosity in your welds.
What Is Under Fill In Welding?
Under fill refers to a discontinuity or insufficient filler metal welded into the groove, resulting in a weld that was thinner overall than the base material it was attached to.
Under fill is a common weld defect that occurs in welding and is caused by a lack of filler metal, high heat input, too slow of travel speed, lack of gas coverage, or it could also be caused by the weld pool moving away from the puddle while you are welding.
Under-fills are a major concern in welding because they leave an open void at the root of the weld; this increases risk for cracking due to stress concentration.
What Is A Root Run In Welding?
Root run is made by a root pass to determine the penetration of a weld and fusion in order for a formation of a rigid joint.
A welding process is a material joining technique in which the fusing of molten materials, such as metal or plastic, is done by heat. The best weld penetration will ensure that there is complete fusion between the two pieces being joined together.
The roots of a joint are the surfaces of contact between two or more components. The root pass is defined between the base metal and the weld metal during heat input, travel speed, thermal gradient, and shielding gas flow rate.
When using a root run weld process, you can improve your welding by ensuring you have good visual feedback of the weld toe vs. your travel speed, thermal gradient, and shielding gas flow rate; these three factors can contribute greatly to a root run problem.
Why Should You Never Change The Current Setting During A Weld?
Current change results in machine damage, this may cause breakdown or premature failure, and the weld can be much different from the original one.
The new setting can cause a deterioration of the quality of the weld but also installation damage. Altering the current setting during welding affects the amount of heat being generated, travel speed, spatter and shielding gas flow rate.
Changing current settings during welding affect weld quality and does not look uniform. But if all these factors have been properly set up in advance, it will undoubtedly change their quality as a result of machine damage.
What Voltage Is Used For Welding?
Welding techniques need high current (50-300A) at a low voltage (10-50V) to generate enough heat for welding.
Voltage is very important in welding to minimize porosity because high voltages can cause porosity and instability.
Low voltage will help weld durability and strength, but will also increase the amount of spatter on the surface which adds a visual element.
Try to keep your voltage at around 90% of your current arc voltage in order for optimum performance.
When welding with a lower voltage, it will take a longer time for it to heat up than if the higher voltage has been used.
What Do Volts Do In Welding?
Welding voltage controls the arc length between the electrode and torch tip. Voltage also affects travel speed of the arc along with spatter, shielding gas flow rate, heat input, and the ability to make fusion in a weld.
The current passes through the potential difference between the electrodes and gets hotter as it increases.
Arc Voltage is based on heat amounts, welding speed, and shielding gas flow rate. Arc voltage shifts to higher values as you increase your current, travel speed, and shield gas flow rates.
Higher voltages require low travel speeds for best results, but will also reduce spatter on the weld surface in order for a more consistent quality appearance.
A high voltage promotes a larger area of fusion by increasing current or increasing travel speed.
What Size Wire Do I Need For A Welder?
8 gauge wire is the most commonly used wire size in welding. It is easy to find and can be used with many different power sources.
8 gauge is recommended for beginners who are just getting started.
10 gauge wire is recommended for those who have been doing welding for a while and are looking to upgrade to a better quality product, or for those who have thicker pieces of material to weld together. While 8 gauge wire can still be used, 10 gauge offers better thermal conductivity which leads to better penetration into the base materials.
Is Thicker Welding Wire Better?
Yes, thicker wire is better when one wants to increase power.
The thicker the wire, the more power it has the higher it will reach higher temperatures while maintaining a lower amount of spatter.
Higher gauge wire is an advantage over lower gauge because smaller diameter wires are more fragile and can break or misalign easily if you do not have a steady hand or if you’re working in a small area.
Thicker wires are more common with welding machines and can be used with higher voltages.
Thinner wires can make a good weld, but they often break down as soon as they come in contact with the metal. Thinner wires will create an opening in the weld which usually leads to weakening and cracking.
How Do You Stop A Welder From Tripping The Breaker?
Try plugging another known-good item into the same outlet to see if it behaves similarly, if it does then the tripped item is causing the breaker to trip.
Try clearing your welders fuse and restarting by unplugging the welder and plugging in another known-good item into that same outlet, if it starts up then you know it is not tripping the breaker.
If this doesn’t work, try shutting off your fuses one at a time to see which one trips when you do, if it helps then there is a short in your house wiring or circuit breaker.
