Introduction: Basic Guide to Flux Cored Arc Welding
Hello and welcome to the SLO Makerspace guide to Flux Cored Arc Welding! This Instructable is intended to teach you how to use the Lincoln Weld Pak HD flux cored arc welder. This machine is one of the most basic welders available on the market today and is known for being both user-friendly and cost efficient. Although there are several limitations as to what you can get away with welding on this machine, it is a great welder for beginners and is perfect for doing non-structural, ornamental welding.
Here are some Weld Pack HD product specifications provided by Lincoln Electric:
- Welds mild steel with a gasless, flux core wire electrode
- Welds up to 1/8 in. mild steel
- Plugs into household 115V, 20 amp outlet
- 35-88 amps output
- Cold contactor safety feature keeps welding wire electrically cold until the gun trigger is pressed
For more information in regards to this particular welder, please read the operator's manual: HERE
The first and most important thing to consider while using this machine is... you guessed it, SAFETY! Not only is the electricity required for arc welding extremely hot, but it also generates dangerous UV light that can easily damage your eyes if you look directly at it. This is why you should always use the proper Personal Protection Equipment (PPE) while working on your welding project. This includes, but is not limited to: safety glasses, leather welding jacket, welding gloves, and of course, the welding mask (also known as a welding hood). It also really helps if you have long pants and close-toed shoes. Flux Cored Arc Welding (FCAW) is known to generate lots of sparks that can easily burn any unprotected areas of your body, so cover up! These sparks can also easily start a fire so any flammable materials should be kept at a reasonable distance from the welding area.
That being said, welding can be a fun and exciting way to make things out of metal and after a bit of practice, there is endless potential to make some really cool stuff, so lets get started!
Step 1: Gather Necessary Equipment
Before you start welding you will need to make sure you have all the tools required for the project at hand. The following list should contain everything you will need over the course of your welding project:
- Safety Glasses
- Welding Mask
- Gloves
- Leather Jacket
- Ear Protection
- Pliers
- Chipping Hammer
- Wire Brush
- Grinder with cutting/grinding/wire wheels
- Clamps
- Magnets
- Tape Measure/Metal Ruler
- Fume Extractor
- and if course, the Welder!
Step 2: Clean Your Metal
Although FCAW is known for being a process that can get away with welding dirty metal, it is still important to clean the area of the metal you plan on welding. This is generally done with some sort of wire brush, grinder, or even better, a grinder with a wire wheel. Removing contaminates such as rust or paint will drastically increase the quality of your welds, so taking the time to clean up your project before you start welding is always a good idea.
Prior to taking the grinder to your work-piece, you should always take steps to make sure the metal you plan on grinding is secure. This generally done with clamps, preferably not spring clamps as they don't always exert the necessary force required to keep the metal in place while grinding on it. Personally, I like to use either the table vice or a C-clamp, as they allow you to control the amount of pressure being applied to the work-piece.
Once the metal is secure, you are free to grind away until you have removed the majority of whatever it is that is getting in the way of the bare metal that is necessary for a good weld.
*Reminder: While grinding, be sure to direct any sparks in a safe direction (i.e. not towards a person or a flammable object)
Step 3: Cut Your Metal
In addition to welding metal that has been sufficiently cleaned, you should also make sure your metal has been cut to the appropriate length. Correctly cutting your metal can be equally if not more difficult than the actual welding, depending on what you are working with.
An accurate cut starts with accurate an accurate scribe, or mark, on the work-piece. This is generally done with a soap stone or sharpie, and a ruler with a straight edge. For this demonstration I've chosen to keep it fairly simple and make a 2" x 2" x 2" container out of sheet metal. Therefore, I will need 5 2" x 2" squares in order to complete my project. I first scribe a line 2 inches away from the edge of my sheet metal, going all the way across it. Then, I scribe a series of vertical lines going from the edge of the sheet metal to my first scribed line until I have 5 squares drawn in sharpie on my work-piece. Now I am ready to cut!
When cutting extended lengths of sheet metal it is a good idea to use some sort of guide to ensure a straight cut. I decided to use a long piece of square bar stock to help me maintain my first, and most important cut. After that I just did my best to follow my scribe lines and thankfully they turned out alright. For each cut you should clamp the work-piece down so that it doesn't go anywhere once you begin cutting.
Step 4: Set Up Your Work Piece
Once you have cleaned your metal and cut it to the appropriate dimensions, it is time to get your work-piece set up so that you can easily tack-weld it together without having to fight with it too much. For mass production work, this is where you would typically devise some sort of jig that would allow you easily to set your pieces into place without having to think about it. For this project, I'm just going to use a magnet with a 90 degree angle in order to make sure my square container doesn't turn into a trapezoid container.
Making sure that the pieces you plan on welding together are secured in the exact position you plan on welding them is extremely important. Welding loose materials can lead to countless mistakes and can add unwanted extra work to your project, so make sure to double and triple check your work-piece before you lay down your first tack weld. After you've lined everything up accurately, it is time to start welding!
Step 5: Turn on Welder and Adjust Settings
Of course, adjusting the welder to the appropriate settings is another essential part of this project. Since the sheet metal for our container is a fairly thin gauge (approx. 1/16"), I will be welding on the LOW 1 setting with the wire speed set to 7. As the metal you are welding increases in thickness, you will want to increase the voltage and wire speed as you see fit. It is always good to do a couple test welds on some scrap metal to make sure your settings are right where they need to be before you actually start on your project.
If you are unsure about what settings you should use for your own project, refer to the "suggested settings" section of the welding parameter image that has been provided.
For additional tips, the last four sections of that same image give some valuable information on proper technique while welding.
Step 6: Tack-Weld the Work Piece
After you've got everything lined up correctly and set your welder to the appropriate settings, tack-weld each corner of your work piece together. When tack welding, it is important to make sure that you are actually fusing both sides of the metal together. When you pull the trigger on the torch, pay attention to where you are depositing the weld metal and that you are hitting the work-piece exactly where one piece comes in contact with another. Welding one side more than the other will lead to a lack of fusion which can result in the two pieces of metal not joining together properly. Remember to clean up the area you just welded with the wire brush to remove any slag generated from the tack weld.
Ideally, once you have tacked each corner together, the box will have taken shape and you will be able to see if each side is aligned and welded into the right position. If not, now is the time to fix your mistakes, as they will be much harder to correct after you finish welding!
Step 7: Fill in the Remaining Areas With 'Bead' Welds
Assuming that you tacked everything together correctly, you can now go back and fill in the remaining seams with bead welds. This is where you will really get to hone in your welding skills, so pay close attention to how your torch angle, travel speed, and electrical stickout affect the appearance of your welds.
The most important thing to consider while performing these welds is maintaining consistency in the above categories. In other words, once you've figured out the proper torch angle, don't change it mid-weld. Your travel speed should be fairly fast, and you don't want to speed up or slow down mid weld, but maintain a constant pace. Lastly, your electrical stickout should never be more than 1/2" or less than 1/4", so keeping it at around 3/8" will be your best bet.
Mastering the consistency of your welding technique is the key to being able to weld proficiently, and it's going to take some practice before your welds come out looking perfect. Keep this in mind if they don't look great on your first try, just be patient remind yourself that practice makes perfect!
Step 8: Clean Up Your Piece
After you've welded everything together, there is going to be a bunch of spatter and slag left over from the flux. Now is the time to use the chipping hammer and wire brush to remove as much of this as possible before we start grinding.
Once you've removed as much as you can by hand, grab your pair of locking pliers and clamp it to one of the outside edges of the container. Carefully use the bench grinder to grind down your welds until you've basically removed the outer layers of your weld and the corners are flush with the sides. While grinding, make sure you keep the work-piece safely rested on the guard. You will probably have to re-clamp your locking pliers once or twice in order to effectively grind each corner. If you welded the edges correctly, each corner should look like a seamless transition on each side and should be free of any holes or cracks. If not, you may need to go back and re-weld the areas with defects and repeat the cleaning/grinding process until you reach the desired results.
At this point you are basically done with your container! If you still aren't satisfied with how it looks you are welcome to add your own modifications like a lid, or maybe some paint. Great job!
Step 9: Clean Up the Area
Pretty self-explanatory.. Clean up the area you were working at and put all the tools back where you found them.
Thank you!
Step 10: Profit!
Once you're comfortable welding, try to get creative and make something awesome like this robot!

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52 Comments
Tip 5 years ago on Step 8
If you have to grind your welds to make them look good, that makes you a grinder, not a welder. Practice and then practice more. Weld everyday, then weld more!!
Reply 2 years ago
If you just want them to look good, you are an artist! Ever see a row of dimes on a welded seam of a car body? If you can weld effectively you are a welder whether you want to view a row of dimes or a smooth surface.
3 years ago
OK, probably a stupid/idiot question but...............
I've tried stick welding in the past where you have the flux-covered solid welding rod clamped into the holder and never could hold it steady enough and close enough to keep the arc and yet far enough away to not get it stuck to the work piece (some coated rods supposedly burn almost like a candle where there's a inverted cone that allows the flux to touch but keeps the inner metal rod a fraction of an inch away to produce the arc but even those never really worked for me.)
With flux-cored wire, do you still need that gap or does the wire actually stay in contact with the work-piece? I.e. the other arc welding is almost like taking a candle and holding it a bit away and dripping the wax onto the work as it melts, where-as TIG/gas welding, brazing and soldering is like taking another source to heat the surface and touching the wax directly to the surface and melting it from direct-contact heat transfer (and yes, I realize melting wax is nothing like welding but.............) And spot-welding requires not only the contact but a fair amount of pressure as well and actually will NOT work if the electrodes don't make contact.
So is flux-core metal wire the NFL full-contact welding or is it your grade-school flag-football of "get close but not TOO close"? I haven't seen anywhere where it says "touch the wire to the work" but also nowhere that says "hold it out a fraction or so." I'm thinking it uses the contact method but............................
8 years ago on Introduction
Does flux core welding work with 316 stainless steel?
Reply 3 years ago
I have seen stainless flux core wire for sale online that had good reviews and claimed to work, but have never heard of anyone using it. TIG is certainly the best looking, but MIG would be easier for a beginner and can also weld stainless.
Reply 8 years ago on Introduction
you are better to use "TIG" for stainless, much better looking weld.
3 years ago on Step 10
You’ve done a nice job with this instructable: clear, organized, helpful. Thanks!
5 years ago
very informative for a novice like me, who is planning to enter into this hobby. Thanks for such a nice instructables.
6 years ago
Would you specify about the placement of the Welder's grounding electrode? I did not see where it was placed in this example? Does it attach to the metal table my workpiece is resting on or does it clamp directly to the workpiece I am welding? Thanks!
Reply 6 years ago
Usually the rule of thumb is closest u can get the ground the better if its possible attach the ground to the work piece usually i likento make a nice shiny corner specifically for attaching my ground
Reply 6 years ago
Thanks for your interest. There are different reasons to do either. While it is very common practice to just attach the clamp to the table, do be careful to make sure that your work piece has a good contact with the table. If it is light, can roll or otherwise move around, be sure to clamp it to your table. This is a serious point of safety. Welding can be very dangerous, stay safe!
6 years ago
Step number nine is the most imortant.
Reply 6 years ago
Dad?
8 years ago on Step 10
Very good effort. Well presented!
About that vacuum cleaner though. Never use a vacuum clean as a fume extractor for welding. Ever hear of a dust explosion? Suck a hot spark into a vacuum cleaner tank and you may get to see one first hand.
Reply 8 years ago on Introduction
The fume extractor pictured is not a vacuum cleaner. It is a portable fume extractor made by Lincoln Electric. Thank you for the input though, I'll keep that in mind if I ever catch somebody trying to use the shop vac to extract welding fumes!
Reply 8 years ago on Introduction
Sorry man. Totally looked like a shop vac to me.
Reply 7 years ago
i know lincoln electric company. i am from china and this company has a branch in our city. but i am only engaged in produce welding wires & fluxes for submerged arc welding process. But still, i think this article is really helpful to me. It brings more knowledge about welding to us. To know more about welding fluxes.
http://www.ylflux.com/
7 years ago
Excellent Article on this forum. FCAW process was introduced as a combination of Stick and MIG process for those welding jobs that require specific conditions common in both processes. Besides suitable welding parameters, the maintenance of flux wires is another major factor to produce quality welds. you can find further useful information on FCAW process here
http://www.weldpedia.com/2014/07/six-common-mistak...
7 years ago on Introduction
I'm sorry to hear that mikecz, I knew that you had to take some precautions after having a pacemaker, but I had no idea at the extent or variety of risks. Is there any reason why arc welding is a problem and does that include other types of welding? I am in an auto shop class right now, and we are just learning about welding, it's pretty fun, and I'd hate to have to avoid it all the time.
Yvon Lebras | http://www.sheridanmetal.com/en/
8 years ago on Introduction
BEWARE!!! Just last week they put a heart pacemaker in me. (So far, so good with the pacemaker.) But, AFTER they put it in they tell me:
No arc welding ! (Don't even get close!)
Don't stand/lean over a running engine!
Don't play with commercial or even ham radio transmitters!
Don't stand near radar units! (Guys are putting them on pretty small boats now.)
Hold your cell phone in right hand (pacemaker in upper left chest).
I guess I really needed the pacemaker, but still, I wish they would have told me all these problems with the things BEFORE they put it in me!