Thursday, December 3, 2015

Common Mig Welding Mistakes – Avoidance and Quality

There is a lot that can go wrong with Mig welding. The common mistakes associated with this type of welding and how to get it right are all mentioned below. If those mistakes are taken care of, Mig welding will be easy to do. 

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Common-Mig-Welding-Mistakes-Avoidance-and-Quality

Welding is an awesome skill. Not all can be able to weld and persistently stick to this career. That is why when your welders perform this kind of task, make sure they are well versed about it for their own safety and better work productivity.

For Mig welding, there is a lot that can go wrong with this type of welding. The frequent mistakes associated with Mig welding and how to get it right are all mentioned below by VMST – a veteran provider of welding manpower. 

COMMON MIG WELDING MISTAKES

The parts to be welded have to be very clean. Dirt and paint should not be there when the parts are being welded. This is a general mistake made by a rookie welder. If the parts and the surface to be welded aren’t clean, the weld won’t be proper and a bad weld will be the consequence. 

While Mig welding, you need use the right type of gas. Some people may tend to use cheap variety of gas. It will be cheap to just use carbon dioxide, but a mixture of gases will generate the desired result and good welding. 

If the polarity is wrong, the weld bead that is created won’t look good. 

The sizes of contact tip should be right. 

The speed shouldn’t be too slow or too fast.

During welding, the wind should be blocked and should lead to proper shielding.

If the welding is really cool on a big piece of material, proper welding won’t take place. 

The sizes of welding machine should be right. A very small machine for a very large material won’t do the work properly. 

The components of wire feeders – for example, contact tips, liner and other parts should be properly maintained to give the desired result of proper welding.

The filler material should have the right tensile strength. If this is not correctly matched, the result won’t be right. 

When welding up a joint, some welders leave too large or uneven of the gap in between two panels that they’re joining. You may want a really small gap on some joints, but in most cases, there will be next-to-no gap between the panels when welding. Too large of a gap, then you will have trouble with the bead burning away the panel edges and enlarging the gap. 

So it’s necessary to follow some rules to get Mig welding right. 

HOW TO GET MIG WELDING RIGHT

1. Cleanliness is the King – There are times you can’t always get your work area surgically clean when Mig welding. Still, you should take every step possible to do it if you expect a clean, strong weld. Your work area should be free of all grease, rust and coatings. This can be done with a wire wheel or a grinder.

2. Set up Mig welding machine properly - It has 3 settings: voltage, wire speed feed, and shielding gas flow rate. On the interior panel of Mig welder, there will be the chart that will give you the correct setting for different materials according to their thickness. The shield gas flow rate should be protected from surrounding air. 

3. Check your polarity settings – If you’re welding with the solid wire, set your machine to the reverse polarity (DCEP – Direct current electrode positive). But if you’re welding with flux core Mig wires, you may want to use the DCEN setting (Direct current electrode negative). You should also experiment a little on some scrap metal. Indeed, you should definitely practice on scrap metal if you are not sure which setting is right!

4. Check your ground - You welder is poorly or inconsistently welding, even after you tested your settings on some scrap metal? A chance is that you have a poor ground. Besides having as clean of a work area as possible, you need a clean surface to ground your machine. If you don’t have a good spot to clamp to, then tack weld a stud or a bolt to your work area to get a good continuous ground.  

5. Check your gas – To make a clean weld, the weld puddle needs purifying whilst it is being formed. This is where the shielding gas is brought into play. It is one of other essential keys to producing a clean weld. Make sure you have a sufficient amount of gas coming out of nozzles when welding; the amount needed can vary by the conditions that you’re welding (try to be out of such direct moving air as wind, fans, etc.) and the surfaces that you’re welding on. Mig welding can be done with machines only using flux core Mig wire though, you’re suggested to choose a Mig welder which is versatile enough to use gas as well. Welding with shielding gas is the best way to create the cleanest weld with little-to-no cleanup. 

6. Use the proper welding technique - The welding technique for all welding types is the same. People use the weave technique with a side to side motion, or the whipping technique with a back to forth motion, a circular motion. Whatever technique is used, the wire stickout shouldn’t exceed three-fourth of an inch. Otherwise, the shielding gas won’t be able to do the work properly.

7. Stickout has influence - When setting up your machine, you need make sure that you have your contact tip sticking out the right amount for the welding type you are doing. The rule of thumb is that the welding tip has less than ½" of stickout. You can get away with a bit more if you’re welding on the thinner sheet metal (body panels, etc.). Still, you need stick in that range for just about all applications. Always check your stickout each time before welding.

8. Proper joint construction – Take time to put together an even, tight gapped joint. Doing so will better the final appearance and the strength of the job. The proper joint prep can be panel holding system, intergrip panel clamps, welding clamp plier set.  

auto-dimming-helmet
A good welding helmet helps with your final weld quality.
9. Use auto-dimming helmet – Static darkness welding helmet works ok if you’re in a really well light area or if you’re good at flipping down your helmet and striking an arc in quick motion at the same time. Still, with today's advancements in the welding accessories, it isn’t necessary anymore. Now you can find cost-efficient, quality auto dim welding helmets quite easily. Being comfortable when welding helps you better your weld quality and allows you to see your work area properly before, during and after you weld.

10. The angle matters – The tip angle when welding can also really important. Ideally, you should be straight on when you’re doing quick spot or plugging welds, whilst keeping roughly a 10 degree angle when welding with the pulling or pushing method is satisfactory.  

11. Choose the correct wire size - ‘Bigger is better’ doesn’t always hold true in this case. It is also dependent on the welding type you’re doing and the surface you’re welding on. If you’re mostly working with such thin metal as body panels of a car, you would want to use .023 solid core wire. That will allow you to keep down the temps as opposed to using a much thicker wire. And in case you didn’t know, too much heat is equal to metal warpage. Keep in mind though, if you’re doing chassis or suspension work that the metal is substantially thicker, you would want to use .30 or .35 solid core wire. This will ask for 110 machines to run at the higher end of voltage spectrum. 

12. Be safe - There are lots of hazards of welding, lots of them are pretty obvious, whilst others can be easily overlooked. Make sure you wear the proper attire when welding. That means long pants, leather welding gloves, welding jacket, closed toe shoes. Dressing properly can save you from being seriously burnt from the intense heat and light generated when welding. Also, keep in mind that you need keep your work area safe. Rather, cover or remove all flammable objects from the work area, and allow for proper ventilation from any fumes that can be generated when welding. 

13. Give regular Mig maintenance - One of easiest ways to make your Mig gun run more seamlessly is to replace the liner. A wire, oftentimes, will start to jam or at least run less smooth than before. Still, if you keep some liners handy, you will be prepared to get a new one when you need it. The loss of weld quality, loss of time on task, and the like make some investment in a new liner worth it. Also, take time to clean out spatter for the Mig gun and replace the torch tip when necessary. When you can keep a steady flow of electrode into weld puddle, Mig welding works best. 

There are lots of things that can go wrong while Mig welding though, by putting these tips into practice, you will be able to avoid some of most common mistakes that come up while Mig welding. 


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