Identifying Metals
Ferrous contain iron– must be painted Nonferrous has no iron Metals
ColorWeightTextureUseShapeSpark test
Identifying Metals
Spark TestCast iron- red linesHigh carbon steel- yellow lines/star burstsWrought iron- straw colored lines w/o bursts
Galvanized steel should not be cut or welded
Oxy-Fuel Procedures
Used to cut through metal, heat for bending, or for welding
Fuels include propane, propylene, or acetylene
Acetylene is most often used Oxygen enhances the flame-will not
burn
Oxy-Fuel
Use soapy water to check for leaks in hoses
Acetylene pressure should be less than 15psi
Open the acetylene valve ¼ to ½ turn Only use spark lighter
Types of Flames
When first lit, you have a carbonizing flame
Oxygen is adding to make a neutral flame
Extra oxygen makes an oxidizing flame for special applications where extra heat is needed
Arc Welding AC- inexpensive welder used most of
the time DC- generator operated, used where
power is not available Some welders are both AC and DC
Welding
TIG- Tungsten Inert Gas Good for welding stainless steel &
aluminum Gas supply is helium & argon
Welding Procedures
Metal should be cleaned before welding ¼” or thicker metal should be beveled &
place 1/16 to 1/8” apart
Setting the Amperage
Amperage too low causes a narrow, high bead with poor penetration.
Amperage too high caused a flat bead with excessive spatter.
Correct amperage helps make a uniform bead with bead width and penetration depth equal to each other.