Spot Welding Equipment

Tooluxe Pro-Quality 115V 1/8" Electric Spot Welder

Amazon Price: $250.00

Electric Spot Welder - 30 Rated Duty

Features:
» Rating Input Voltage V: 110V
» Rated Duty %: 30
» Class Insulation: H; Applied Spot Welding Thickness: 1.0+1.0
» Including: 2 Extra Tong Tips (total 4)
» Quantity: 1

Amazon Price:

Electrode Electric Spot Welder Welding - 30 Rated Duty

Features:
» Rating Input Voltage V: 110V
» Rated Duty %: 30
» Class Insulation: H
» Applied Spot Welding Thickness: 1.0+1.0
» Including: 2 Extra Tong Tips (total 4)

Amazon Price:

Lenco (LNXL4000) Autobody Dual-Spot Welder

Features:
» Sold Individually

Amazon Price: $1,450.00

Hobart 040872 SWP-2 Spot Welder Pedestal

Features:
» Spot welder
» Leaves hands free
» Foot Control is depressed

Amazon Price: $325.50

Hobart 770496 Contact Tip and Electrode Kit for AirForce 250Ci Plasma Torch, 2-Pack

Features:
» Torch consumables kit
» For air force 250ci

Hobart H722844-RDP 1/8-Inch 4043 Aluminum Electrodes

Features:
» Aluminum welding for flat, horizontal and vertical applications.
» DC (electrode positive) only.

Hobart H480644-RDP 1/8-Inch 312 Plus Electrodes, Stainless

Features:
» For hard-to-weld or dissimilar metals, stainless, high-carbon, cast and high-nickel steels.
» All-position, AC or DC (electrode positive), easy strike and re-strike, high moisture resistance, self-detaching slag.
» Size 1/8-Inch Quantity 5

Hobart H481930-RDP 308L Electrodes, Stainless Steel, 3/32-Inch

Features:
» For 308 and 304 stainless base metal.
» Smooth, tough welds with the strength, corrosion and crack resistance needed for welding stainless steel in all positions.
» AC or DC electrode positive (reverse) polarity.

Hobart H500631-RDP 3/32-Inch Nickel 55 Electrodes

Features:
» For repair in all positions of materials with 55-Percent-nickel cast iron.
» This electrode produces welds with higher strengths and ductility than the straight nickel electrodes.
» Deposits are machinable, but harder and more resistant to cracks and abrasion than high-nickel welds.

Here are some usefule videos about spot welding. If you're new to spot welding you can really learn a lot from them.
* Resistance Spot Welding - How It Works
* Classic Car Restoration - Resistance Spot Welding Rocker Panels
* Homemade spot welder
* Homemade Capacitor Spot welder
* Laser Spot Welding

Spot welding (RSW) is a process in which contacting metal surfaces are joined by the heat obtained from resistance to electric current flow. Work-pieces are held together under pressure exerted by electrodes. Typically the sheets are in the 0.5 to 3 mm (0.020 to 0.12 in) thickness range. The process uses two shaped copper alloy electrodes to concentrate welding current into a small "spot" and to simultaneously clamp the sheets together. Forcing a large current through the spot will melt the metal and form the weld. The attractive feature of spot welding is a lot of energy can be delivered to the spot in a very short time (approximately ten milliseconds). That permits the welding to occur without excessive heating to the rest of the sheet.

The amount of heat (energy) delivered to the spot is determined by the resistance between the electrodes and the amplitude and duration of the current. The amount of energy is chosen to match the sheet's material properties, its thickness, and type of electrodes. Applying too little energy won't melt the metal or will make a poor weld. Applying too much energy will melt too much metal, eject molten material, and make a hole rather than a weld. Another attractive feature of spot welding is the energy delivered to the spot can be controlled to produce reliable welds.

Projection welding is a modification of spot welding. In this process the weld is localized by means of raised sections, or projections, on one or both of the workpieces to be joined. heat is concentrated at the projections, which permits the welding of heavier sections or the closer spacing of welds. The projections can also serve as a means of positioning the workpieces.

Projection welding is often used to weld studs, nuts, and other screw machine parts to metal plate. It's also frequently used to join crossed wires and bars. This is another high-production process, and multiple projection welds can be arranged by suitable designing and jigging.

Source : Wiki