Welding Resources and Tips

The Best Tungsten for TIG Welding Aluminum

With all of the different TIG machines around, with some offering inverter technology and all offering varying degrees of power, it can be tough to figure out the best tungsten for TIG welding aluminum. Welders have shared stories of 2% thoriated electrodes balling up and pure tungsten welds leaving a mess of metal to grind down for the rest of the afternoon. With that in mind, what is the best tungsten electrode for TIG welding aluminum?

 

The Tungsten you choose will depend in large part on your particular machine, the thickness of the metal you’re welding, and the settings you have available. Here are a few tips and general rules that will help you get started. Keep in mind that some of these tips may change based on your particular machine.

Learn About Tungsten for TIG Welding Aluminum

The following electrodes can be used for TIG welding aluminum, but there are a few rules and caveats that will need to be discussed below:

• Orange: 2% ceriated (on AC)
• Blue: 2% lanthanated (AC and DC)
• Gold 1.5 lanthanated (AC and DC)
• Red: 2% thoriated (DC only)
• Green: pure tungsten (DC only)

Don’t use green on the AC side since pure tungsten will ball up, especially if you’re using an inverter. Some welders have a particular favorite kind of tungsten. They may swear by thoriated or pure tungsten. The truth is that each kind of tungsten listed above can work if you have the right settings and the right application.

The tough part is that it’s easy to mess up when TIG welding aluminum, so there are plenty of other things to consider.

The Electrode Size for TIG Welding Aluminum

One of the most common mistakes for welders working with aluminum is they choose an electrode that is too small. You often need to consider a 1/8” electrode for welding aluminum in order to get enough heat and to create a stable arc. Too small an electrode will create a sloppy weld.

If you’re working on AC with a lanthanated electrode, you may be able to use a 3/16” or 3/32” electrode. The key is to match your electrode choice and size with the settings and the project.

The Best All Around Electrode for TIG Welding Aluminum

While each tungsten electrode has its advantages and disadvantages, one of the safest bets is 2% lanthanated that is ground to a point with a flattened tip. Many welders prefer lanthanated for both AC and DC because it holds up well and provides a stable arc for a clean weld.

Learn more about how to choose the best electrode.

 

How to MIG Weld Aluminum

MIG welders are extremely versatile welders that can handle a wide variety of projects. However, before you buy a spool of aluminum wire and try MIG welding aluminum, you’ll want to learn about the particular challenges and adaptations you’ll need to make before attempting to MIG weld aluminum.

Image Source: ThomasNet

Use 14 Guage or Higher for MIG Welding Aluminum

The one challenge you’ll face when trying to weld aluminum is that a MIG welder may have too much power for thinner sheets of aluminum. A good rule of thumb is that you’ll weld aluminum that is 14 gauge and higher. Thinner aluminum will need a pulse setting for a MIG welder. Otherwise, use a TIG welder.

Torch Position for MIG Welding Aluminum

A 10-15 degree torch angle will be ideal for MIG welding aluminum. You’ll also want to push your torch while welding rather than pulling it. A straight, steady torch movement is ideal for MIG welding aluminum so that the impurities stay outside of the weld puddle. Some welders suggest inching forward and then pausing before inching forward again so that your final weld has a neat, uniform appearance.

Use a Spool Gun to MIG Weld Aluminum

A spool gun will save you a ton of time and aggravation since aluminum wire is too soft to effectively feed through a MIG machine. It will keep getting jammed, and you’ll have a frustrating time at it. Spool guns attach to your MIG gun and then feed the wire right into the torch. 

Use Spray Transfer for MIG Welding Aluminum

You’ll use a longer electrode stick out for MIG welding aluminum and the melted aluminum will be sprayed into the weld puddle. If you hear the crackle you usually hear when you’re welding steel, you’re doing something wrong. Your wire feed speed is most likely too fast. Though it’s usually ideal to start a little on the fast end and then adjust the speed as you go, having too fast a wire speed will add too much metal and possibly damage your metal work piece.

Clean the Aluminum Before MIG Welding

Solvents such as acetone are usually ideal for cleaning metal, but if you have a lot of mill scale, you may want to grind down the metal first before prepping the weld.

Use Straight Argon for Aluminum MIG Welding

Though some gas mixtures can be used as a shielding gas for MIG welding aluminum, the majority of situations will call for a simple tank of argon. You’ll need to weld with argon using reverse polarity or DCEP.

Pick Up A Complete MIG Welding Set Up

MIG welding aluminum requires materials and parts beyond what comes with a typical MIG welder. The best way to ensure that you have everything you need for the lowest price is to pick up an aluminum MIG welding set up from Baker’s Gas and Welding.

Besides the typical MIG welding features, this set up also includes:

300371 - Miller Spoolmate 100 (spool gun)

249176 - Miller Arc Armor MIG Glove - Large

195149 - Miller Protective Cover

4043030X1SP - Weldcote ER4043 .030" Aluminum Wire - 1 lb

Learn more about MIG welding at Baker’s Gas and Welding.

 

Tips for TIG Welding Aluminum

TIG welding aluminum can be frustrating to the uninitiated, but if you make the right preparations and work on your technique, you can join aluminum together without melting or warping the metal and without wrecking your weld in the process. While you may have the TIG welder and aluminum set up and ready to go, take a moment to read these tips on how to prepare to weld it properly.

 Image Source: http://www.engr.ncsu.edu

Use a Heatsink

One way you can prevent the aluminum from warping while you work on it is to use a copper or aluminum heatsinks. Heatsinks absorb or “sink” the heat that would otherwise be transferred in your aluminum work piece that can get really hot and distorted when you’re ready to start welding.

Consider Preheating the Aluminum Work Piece

We suggest that you “consider” preheating because it isn’t right for every project, especially thin aluminum. However, there are many welders who swear by preheating. When it comes to TIG welding a thicker piece of aluminum, some lower powered TIG welders simply won’t be able to get good penetration and to make a clean, strong weld. You need to make sure you have the right situation for preheating before giving it a try on aluminum.

By preheating the aluminum, you will make it easier for your TIG welder to strike an arc and create a smooth weld without the risk of overheating or failing to penetrate deep into the metal. Suggestions and projects will vary here, but preheating with a propane torch or other heating fuel set up will work just fine. An infrared thermometer will tell you when the metal is hot enough, with 350 degrees usually working for most projects, but higher and lower temperatures work as well.

Clean the Tungsten When It Is Contaminated

When your tungsten electrode touches the metal or weld puddle, it will become contaminated and will make welding with a tight arc extremely difficult. Your arc will become erratic and your weld quality will suffer.

You’ll clean the tungsten by removing it, laying it on a flat surface with the contaminated section pointed over the edge, and then hammering off the contaminated part. You can then ball the end of the electrode again by using the DCEP setting on some scrap metal before transitioning back to AC and getting back to work.

There are a lot of things that can go wrong while TIG welding, but these tips will help you set up your welding project and save you from some real headaches while you work. The best part is that the more you do each of the things in this list, the better you’ll become at recognizing what you need for each TIG welding project. 

 

How to Successfully Weld Steel Pipe to Stainless Steel Pipe

Joining two pieces of dissimilar metals can be somewhat tricky; however, TIG, MIG and stick welding are all capable of successfully welding steel pipe to stainless steel pipe.  The important thing is to know which types of electrodes will produce the desired weld; for MIG welding using an E70 electrode will hold the pieces of pipe together and a 7018 electrode for stick welding will do the same.  But in order for the weld to seal properly, a high-carbon stainless steel electrode must be used.  The preferred electrode to use when the joint needs to be sealed is a 309 electrode. This electrode will ensure that the weld has good penetration and seals properly.

To begin welding steel pipe to stainless steel pipe you should start by cutting the end off of the welding wire that may be sticking out of the welding tip of the MIG welder.  This can easily be trimmed using wire cutters.  Next you will need to back spool the welding wire in order to remove the welding wire from the MIG gun and lead.  Once you have back spooled the welding wire and removed it from the gun you will now need to load the welding gun with the 309 welding wire.  Now that your welding gun is loaded with the proper wire, your next step is to exchange the gas with the three part shielding gas mixture needed for this type of welding.  To ensure that the gases have been properly mixed, you should lay the tank on its side and gently roll it back and forth.  Once you are satisfied and feel that the gas has been thoroughly combined you can then attach the gas gauges to the gas cylinder.

Now that your shielding gases have been properly attached, you can now power on the MIG welder and set the heat and wire speed to the proper setting.  Because welding stainless steel requires a higher level of heat than carbon steel, you will need to look at your welding guide to determine the proper heat level for stainless steel.  Once your machine is set for stainless steel, you should test it on a scrap piece of metal to make sure that everything is working properly.  When you feel that your machine is properly set you can now begin to weld the two pieces of pipe together. 

You should begin your weld on the stainless steel pipe and pull the weld puddle onto the carbon steel pipe.  Roll your MIG gun in a circle pattern to flow the puddle while dropping 1/8^th of an inch at each down stroke to create a roll of dimes weld.  While welding you should watch the bottom of the weld to ensure that proper penetration is being achieved.  If you notice that the carbon steel pipe is under-cutting, you need to reduce the heat setting on your MIG welder and repeat the process.  If reducing the heat setting fails to improve the level of under-cutting taking place, you should speed up the stroke of your circle so that you can pull the heat away from the steel pipe.  Doing this should help rectify the under-cutting and leave you with a strong sturdy weld.

Once the weld is completed you should inspect the entire surface of the weld to ensure that there aren’t any defects or weak areas.  If you should happen to notice any defects you can go back and remove the weld and do it again.  With some experience you should be able to master this welding technique and your welds will improve each and every time.

Image Credit: Lincoln Electric

Welding Aluminum

The process of welding aluminum requires less energy than welding other metals which typically makes it an easier metal to weld.  While this may sound good, there can also be some problems when you are required to use welding equipment that was designed to be used on steel.  This is why it is important for the welder to consult their owner’s manual in order to find the proper settings that can be used for welding aluminum. 

MIG Welding Aluminum

Welding aluminum using the MIG welding process has been known to require the welder to perform some post-welding touchups to the weld area in order to create a more presentable finish.  The process of MIG welding requires the use of an electrode of continually fed wire which forms the base of the welds.  This electrode also requires the welder to use a shielding gas composed of an inert gas or mixture of two gases.  When MIG welding is performed on aluminum the results may be a bit messier than when other metals are welded.  MIG welding aluminum tends to be messier because of the need for the welder to use the spray transfer welding method where the welding arc creates a spray of tiny metal beads.  With time and practice any welder can master the spray technique.

TIG Welding Aluminum

TIG welding is a welding process that doesn’t require the welder to perform as much post-welding cleanup work as is required in MIG welding.  The ability to produce welds that require little to no post-welding work makes this the perfect welding process to use when fast and easy welds are required on aluminum.  The process of TIG welding requires the use of a permanent tungsten electrode which is not consumed during the welding process.  The welder will still be required to add any necessary filler metal manually.  These requirements and restrictions make this process the best to use when there isn’t any additional metal being used.  TIG welding aluminum also requires the welder to use an inert gas to shield the arc.

These two welding processes are the most common welding techniques used when aluminum is welded.  Both of these welding methods will require some practice in order to master the different techniques.  It also important that the welder check all of the settings on their welding equipment prior to welding.  This will ensure that they are all properly set to weld aluminum.  Welding aluminum properly requires patience and practice as do all welding techniques; but once the skill is mastered it will be much easier to produce high quality welds on aluminum.