Mig Welding Sheet Metal Gaps

There are 2 basic methods to mig welding large gaps the first is to use filler metal to help cover the gap that is cut to size to fill the gap and help make the weld a smoother process.

Mig welding sheet metal gaps.

Overall i ve used both of these methods depending on the situation and the type of metal i m working with. From my standpoint i always have a perfect fit up with mig welding. The gap is to compensate for expansion when the metal gets hot. The less heat the better with better with thin guage.

I don t put sheet metal together with a gap in place because metal shrinks when you weld it. When mig welding sheet metal it is important to set the proper parameters to prevent warping and burn through or else it will create excess heat and easily blowholes on the metal. Often you hear of a gap or bevel when trying to join to thick pieces of metal to ensure maximum penetration. Holding the tip too far from the surface will cause the wire to have to come out too far to touch the metal.

During the welding process the metal will get hot and the gap a welder leaves will compensate for the expansion that occurs. The second is to do a root pass to fill the bottom of the gap and using stringer beads to fill the gap. Mig welding i would think it would be more difficult to weld a gap in short spurts. This means the extra wire causes the voltage to drop by the time it actually gets to the surface and strikes an.

Keep in mind during the welding process it is important to direct the arc right at the center of the weld puddle and don t do movements like whipping or weaving as it may cause warping and burn through quickly. Test fit the panel until only an even 1 16 gap is left around the patch. When mig welding a patch panel on your car body panels you should think of leaving small gaps between the patch panel and the original metal. Keep the stick out short stickout of your mig wire is important when welding any type of metal but especially sheet metal.