Always remember SAFETY FIRST! Proper Clothing and Eye protection along with Welding gloves and Foot protection will ensure personal injury does not result.
One thing you always need to know before welding is the metal you are going to work with. Understanding the properties of the metal will allow you to make good strong and lasting weld. Here is a video I hope helps. There is a series of these and I hope to be able to post them for you!
Here are some basics when mig welding with flux core wire.
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Here is a video on sheet metal welding
Stay tuned for More Welding Posts and Video's.