Mig Welder Contact Tips to work distance
When welders think about safety, they may seldom think about the importance of changing their MIG welding contact tips.
Especially if your not using the correct contact tip to work distance.
The average tip to your work distance for general welding is 3/4 inch / 18mm That is the total distance from the very end of your contact tip to your work .
There is nothing worse than following every safety precaution but still remaining fully at-risk for faulty hardware that simply needs to be replaced.
The following article explains why people need to put more focus on their mig contact tip sizes they use and how to know when & why they should be changed.
Importance of Using the Correct Welding Contact Tip sizes
When choosing the correct contact tips, welders must also choose the correct contact tip size and corresponding MIG welding wire size. The contact tip is very important for ensuring that the welding current can pass through to the consumable wire after passing through the bore.
The wire goes through the welding contact tip, meaning you need your mig welding wire size to match so the pass-through-efficiency and electrical conductivity are kept to maximum.
Contact Tip Sizes & mig contact tip thread
The wire that you are using for your welding work determines the type of contact tip and make sure you match your old mig contact tip thread size when replacing with new tip as this can affect the performance of your mig welding torch also the type of liner that is needed. You must look at the inner diameter of the contact tip to make sure that the wire and welding process is matched to work for optimal welding capacity.
The MIG contact tip is designed to bring the welding current through the device to the wire. If the tip diameter is too small, this will lead to feeding difficulties of the wire. The contact tip diameter must be slightly larger. As long as the diameter is 0.20 mm to 0.23 mm larger than the diameter of the wire, this will be sufficient for welding. However, if the size is too big for the wire and will lead to more problems in the welding process. And remember to keep your contact tip to work distance otherwise you will burn out your tip in no time.
For this very reason, ensure that you do not use a contact tip diameter larger than 0.38 mm, as this will lead to a disproportionate connection between welding contact tip and welding wire sizes.
Types Of Mig Welding & wire
Typically for aluminum wire, the size is 1.2 mm and for steel wire, the size is 1.1 mm. Because of this size increase in aluminum compared to steel wire, the MIG welding contact tip will typically be larger for aluminum wires than with steel wires. Another important distinction to note is that the aluminum wire will expand more under the intense heated conditions than the steel wire will. This means that the bore diameter in aluminum-specific contact tips is larger to account for this slight heat-based size expansion. So it very important to have the correct type of mig welding wire for the job your doing.
When To Change Your Contact Tip
Through regular and consistent use of MIG welding contact tips, there are several key reasons for changing the contact tip to ensure safety.
When faults occur, such as a bad starts, burnbacks, arc failures, or other such faults, this means that the steady arc burning process is unbalanced and unstable. The distance between the contact tip and the work, as well as the wire feed rate can greatly influence the power supply conditions for the welder.
The current and wire extension also greatly influence the melting rate for the welder. However, if there are small irregularities or inconsistencies in the wire extension or the wire feed rate, this can influence the balance of the wire feed rate and the melting rate.
Should the feed rate overpower the melting rate, this can cause stubbing. Burnback happens from the melting rate overpowering the feeding rate. Even if the wire that the welder is using happens to be too stiff, this can lead to a buildup of friction. Should the wire be too soft, the welder will then struggle with a wire that will tangle or bunch up within the welder’s torch. When there is a build-up of left-over metal in the contact tip can even cause wire slippage which can become dangerous and inefficient for the welder to operate with.
Another problem that can occur from infrequent changes of the contact tip is birdnesting. Birdnesting happens when the wire passed through the contact tip bore tangles up. On the other hand, if the bore diameter of the contact tip is too big for the wire, this can cause the wire to wander and lead to a dramatic increase in the keyhole rate, the contact tip wear rate, and cause the contact tip to wear more quickly. This is another central reason for why MIG welding contact tips must be replaced regularly to account for this type of work wear.
Keep Your Welding Torch Clean and Free of Damage
Welders should put a strong emphasis on keeping their welding torch clean of slag and checking their welding torch lead for damage. If the contact tips that the welder is using happen to have bore diameters which tend to be smaller than the norm, this can lead to a buildup of friction. This buildup of friction can then lead to unexpected problems like wire bridging or microspatter buildup within the tip.
There are numerous ways to keep the instruments and supplies clean from slag, such as adding certain welding lubricants. Avoid petroleum lubricants and petroleum-based products as this carbon residual byproduct could effectively clog the bore diameter which you will want to avoid. Also, be sure to use protective liners when the wire is exposed to the elements outside of the welding room.
Additionally, by keeping your mig contact tip bores free from residues, build-up of residual metal, or impurities, this will ensure you keep your welding on track.. If there is build-up of these issues, consider replacing the welding tip.