Welding

Ok, so Iím not a professional welder. Not even close. I like to make things though, and welding together the frame for a rover can be a really rewarding experience. There are much better welding tutorials out there, but as a good friend of mine says, "If the weld holds then your a good welder!"


Introduction:

Welding is a process by which heat is applied to three pieces of metal. Two pieces are the pieces being joined together, and the third is a wire that is being melted to join the two. The product of a good welding joint can be as strong if not stronger than the metal it is made up of because a good weld forms the two work pieces into one.

In a MIG welder, A spool or wire is fed down a tube with a current running through it. A ground wire is attached to one of the two pieces being joined. As the current jumps from the wire to the work pieces and then through them to the ground. This creates a spark which melts the weld wire being fed through the tube. The weld wire melts, and also melts the edges of the work pieces. creating a puddle. The operator uses the spark to pull or push the puddle along the two edges being fused which melds them into one solid piece of metal. In theory it is like squeezing a tube of toothpaste!



Safety:


When welding you are creating enough heat to melt the metals you are welding. If you are welding steel that is about 1400 - 1500 degrees.

Fire: When welding you should wear flame retardant clothing. Leather gloves that come far up the wrist, and a leather shirt or apron are a good starting point. Wear leather boots. Heavy jeans, or heavy canvas pants work. If you are welding in a position where the materials are over your head then you should definitely wear a hat that covers your neck. Trust me when I tell you that having a super hot bleb of metal drip down your back hurts like a B-word!

Make sure your welding station is free of flammable materials. I once had my mother in law stash some oily rags in my shop without telling me...A spark from welding had those rags up in flames in a second. Luckily I noticed the fire before it got out of hand.

Have a fire extinguisher handy. Once you have a fire is no time to go looking for the extinguisher.

In Some situations an adequately protected spotter is a good idea. A second set of hands is always a good idea.

Tie back long hair

NEVER WELD A SEALED TANK!

Light:

The electromagnetic Radiation from the spark is not only damaging to your eyes, but also to your skin. Over time it welding can result in something akin to a sunburn to exposed skin.

Be sure to use your face shield of adequate darkness and safety goggles.

Electric Shock:

Duh...When your welding you have a lot of electricity passing from the gun to the grounding clamp. Having that same electricity pass through your heart will kill you.

When welding make sure you are dry and insulated. Make sure the material you are working with and your gloves are dry.

Never set up a situation in which the electricity can pass from one hand to the other through your body.

Suffocation:

Donít weld zink or galvanized steel. This creates a toxic gas that can kill you. Grind off any paint that may create toxic fumes when burning.

Ok...now on to the good part!

Setup:


Look on the inside of the door of your welder. There you will find a chart showing you what settings you need to use in order to weld the materials you are using. If you are welding two metals of different thicknesses set your welder for the thicker of the two metals. Use the two dials on the front of your welder to set the wire speed and the power level based on the metals you are welding

Clean the metals. If they are greatly oxidized you should grind off the oxidation. Rust has a different melting point and can cause weak penetration, which will cause the weld to fail.

Tack Welds.

A tack weld is a short burst weld which makes a very small bead between the two work pieces. This is just to hold the work in place so that you can perform a proper weld on it. Tack welds also help prevent warping which makes your pieces come out crooked.

Butt Welds.

In a butt weld the operator puts the two pieces of metal side by side, and melts the two edges together. Once you have a good ground connection aim the gun directly into the gap. Squeeze the trigger starting the spark. Wait for a puddle or red metal to form just to the side of the spark. Then Either push or pull the puddle along the gap.

Lap Welds

In a Lap weld one piece of metal is placed above the other so that they overlap a small amount. In this type of weld, you want the gun aimed at a 45 degree angle into the edge of the top piece. Again wait for the puddle to form, and then pull the puddle along the edge of the top piece of metal.

Button Welds

A button weld is a type of lap weld. You drill a hole in the top piece of metal, and then perform a lap weld around the inside of the whole creating a small button.

Clean Up:

Once your done welding, use your angle grinder to grind off the excess metal. If the weld is not going to show it is better to leave the excess in place. This makes the metal stronger.

Making things better:

When people first start welding one mistake they make is that they just start laying beads all over the place. It is a good idea to clamp your work, and use tack welds to preheat the metal. This prevents warping which will distort your end result.



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