“Look after the pennies and the pounds will look after themselves.”
The details will get you if you don’t watch out. To improve your efficiency in MIG welding, one of the things you might want to look at is the nozzle on the MIG gun. If it’s used the way it was designed for, it can help you be more efficient. But if it’s used for something it wasn’t designed for, that could add more post welding work – i.e. the work you don’t get paid for.
Remember that nozzles were made to assist in welding – not to create extra work. So, if the nozzle isn’t doing what you need it to do, maybe it’s not the nozzle’s fault – but rather a sign you need to choose a different nozzle.
Copper is going to be able to withstand intense heat much better than brass. Brass will melt or burn when it’s exposed to extreme heat. But brass resists spatter better than copper.
Some nozzles have more of a taper to allow the welder to get into those tight and/or poor visible welding areas. The opening on the nozzle is going to determine how much gas you get on your weld puddle. If you are welding with high amperage and voltage, then you are concerned with good gas coverage. The larger nozzle is going to give better shielding gas coverage on the welding puddle. The rule of thumb is bigger is better. One other thing to remember is keep the nozzle clean of slag and spatter. This will help keep a good flow of gas.
A non-threaded nozzle is going to be easy to change out because it has no threads. It’s also easier to clean. You can easily adjust the stick out on the wire by moving the nozzle over the insulator to the desired length. But the non-threaded nozzle is more susceptible to human error – i.e. the stick out on the tip might not be what you need for the type of welding you are doing. Plus, it can become loose over time and it doesn’t hold it’s location. The threaded nozzle is going to have a fixed stick out. If you want to standardize the stick out for each welding station or job, you can do it more easily with the threaded nozzle. This can lead to a more consistent result in your welding. But, with the threaded nozzle when it needs to be changed, it could be difficult to take off. The threads, which make for a tight fit, could be the things that make it difficult to change the nozzle. Now you are spending quite a bit more time trying to get the nozzle off.
It’s the length of the wire from the end of the contact tip to the work surface. As the wire stick-out lengthens, voltage goes up and amperage decreases. This can cause the arc to be destabilized – which can produce excessive spatter, wandering arc, slow speed travels and poor heat control on thin metals. Any of those things are going to result in extra work after the welding. Had the tip been at the correct distance, it could’ve eliminated the extra work. Are there any general rules about stick out?
The rule of thumb on recess (or wire stick out), the increase of current should lead to more recess on the tip.
|Recess/Extension||Amperage||Wire Stick Out||Process||Notes|
|1/4-in. Recess||>200 amps||1/2 – 3/4-in.||Spray, High Current Pulse||Metal Cored wire, spray transfer, argon-rich mixed gas|
|1/8-in. Recess||>200 amps||1/2 – 3/4-in.||Spray, High Current Pulse||Metal Cored wire, spray transfer, argon-rich mixed gas|
|Flush||<200 amps||1/4 – 1/2-in.||Short Circuit, Low Current Pulse||Low argon concentrations or 100% CO2|
|1/8-in. Extension||<200 amps||1/4-in.||Short Circuit, Low Current Pulse||Difficult to access joints|
Now, you are equipped to go and check and see if the correct nozzle is being used!