UNITIZED STRUCTURAL BODY REPAIR EXAM QUESTIONS
WITH SOLUTIONS GRADED A+ 2025/2026
✔✔Compression Spot Welding - ✔✔Used by manufactures, but is not recommended for
collision repair. Our equipment makes welds 70-80%of the strength of manufactures.
Manufactures may have technicians use but must follow service manual and special
procedures.
✔✔MIG Welding Wire (Electrode) - ✔✔AWS ER70S-6 AWS ER70S-7
✔✔AWS - ✔✔American Welding Society Standard
✔✔E - ✔✔Type of standard-ELECTRODE
✔✔R - ✔✔Electrode Type-ROD (MIG Wire)
✔✔70 - ✔✔Tensile strength Expresses in Thousands of PSI (70,000)
✔✔S - ✔✔Electrode Type-SOLID
✔✔6 - ✔✔Chemical Make-up / Higher the number, better wire
✔✔.023 Wire - ✔✔Most commonly recommended wire size
✔✔Flux Cored Wires - ✔✔Recommended for steel thicker than 18 Gauge, Galvanized
Steel, but burn through on 20 Gauge and thinner steel.
✔✔Shielding Gases - ✔✔Recommend on steel. Mixture of argon and carbon dioxide.
(Aluminum you use pure argon)
✔✔C-25 - ✔✔Shield Gas, 25% Carbon Dioxide and 75% Argon
✔✔Types of MIG Welders - ✔✔110/120 and 220/240 // Determined by two factors
Output Amp and Duty Cycle
✔✔Output Amp - ✔✔Min 90-100
✔✔Duty Cycle - ✔✔Amount of actual welding time.
✔✔Corrosion Protection - ✔✔Zinc based coatings. Zinc rich weld thru primers, Acid
based metal cleaners and etchers, conversion coatings that form a zinc poshpate layer,
Paint Finishers-sealers, color and clear coats, seam sealers at panel joints and seams,
petroleum and paraffin based compounds.
, ✔✔Restoring Corrosion Protection - ✔✔Soap and Water, wax and Grease remover,
Metal Conditioners, Conversion Coatings, Epoxy Primers, Self Etching Primers, Weld
Thru Primers, Seam Sealers, Wax and Petroleum Based Anti-Corrosion Compounds.
✔✔Soap and Water - ✔✔First material that should be used. water soluble contaminants
are washed away and the surface is rinsed clean.
✔✔Wax and Grease Remover - ✔✔Used after soap and water. Removes tar, wax,
silicones, and other petroleum based contaminants. Clean cotton rag and wipe dry with
a second rag.
✔✔Metal Conditioners - ✔✔Acid clean and etch the surface for the best possible
adhesion of conversion coatings and primers. Do NOT use in enclosed areas where
they can not be washed away.
✔✔Conversion Coatings - ✔✔Follows the metal conditioners and lays down a zinc
phosphate layer that maximizes primer adhesion as well as preventing rust "creep"
under the painted surface. Not to be used in enclosed sections.
✔✔Epoxy Primers - ✔✔Provides a level of corrosion protection closest to that of the
original E-Coat primer. Must be applied soon after the cleaning, etching and conversion
steps.
✔✔Induction Period - ✔✔Some epoxy primers need to sit for a time after mixing.
✔✔Self Etching - ✔✔Eliminates the need for conditioners and conversion coatings.
Must be top coated with a paint finish or anti corrosion compound.
✔✔Weld-Thru Primers - ✔✔Restores the zinc protection that is burned away welding.
Bonds tightly to bare metal and flows back into the weld site as it cools. Primers and
seam sealers do not adhere to it so it must be removed.
✔✔Seam Sealers - ✔✔Need to be replaced in any location that the manufacture
applied them to. Same as what was used, and should be applied after the epoxy or self
etching primers.
✔✔Wax and Petroleum Based Anti-Corrosion Compounds - ✔✔Applied to all enclosed
sections and underbody surfaces.
✔✔Sacrificial Corrosion - ✔✔Seal sacrifices itself against the elements.
✔✔Galvanic Corrosion - ✔✔When 2 metals react to each other. Replace any special
washers, films, gaskets to separate the two metals.
WITH SOLUTIONS GRADED A+ 2025/2026
✔✔Compression Spot Welding - ✔✔Used by manufactures, but is not recommended for
collision repair. Our equipment makes welds 70-80%of the strength of manufactures.
Manufactures may have technicians use but must follow service manual and special
procedures.
✔✔MIG Welding Wire (Electrode) - ✔✔AWS ER70S-6 AWS ER70S-7
✔✔AWS - ✔✔American Welding Society Standard
✔✔E - ✔✔Type of standard-ELECTRODE
✔✔R - ✔✔Electrode Type-ROD (MIG Wire)
✔✔70 - ✔✔Tensile strength Expresses in Thousands of PSI (70,000)
✔✔S - ✔✔Electrode Type-SOLID
✔✔6 - ✔✔Chemical Make-up / Higher the number, better wire
✔✔.023 Wire - ✔✔Most commonly recommended wire size
✔✔Flux Cored Wires - ✔✔Recommended for steel thicker than 18 Gauge, Galvanized
Steel, but burn through on 20 Gauge and thinner steel.
✔✔Shielding Gases - ✔✔Recommend on steel. Mixture of argon and carbon dioxide.
(Aluminum you use pure argon)
✔✔C-25 - ✔✔Shield Gas, 25% Carbon Dioxide and 75% Argon
✔✔Types of MIG Welders - ✔✔110/120 and 220/240 // Determined by two factors
Output Amp and Duty Cycle
✔✔Output Amp - ✔✔Min 90-100
✔✔Duty Cycle - ✔✔Amount of actual welding time.
✔✔Corrosion Protection - ✔✔Zinc based coatings. Zinc rich weld thru primers, Acid
based metal cleaners and etchers, conversion coatings that form a zinc poshpate layer,
Paint Finishers-sealers, color and clear coats, seam sealers at panel joints and seams,
petroleum and paraffin based compounds.
, ✔✔Restoring Corrosion Protection - ✔✔Soap and Water, wax and Grease remover,
Metal Conditioners, Conversion Coatings, Epoxy Primers, Self Etching Primers, Weld
Thru Primers, Seam Sealers, Wax and Petroleum Based Anti-Corrosion Compounds.
✔✔Soap and Water - ✔✔First material that should be used. water soluble contaminants
are washed away and the surface is rinsed clean.
✔✔Wax and Grease Remover - ✔✔Used after soap and water. Removes tar, wax,
silicones, and other petroleum based contaminants. Clean cotton rag and wipe dry with
a second rag.
✔✔Metal Conditioners - ✔✔Acid clean and etch the surface for the best possible
adhesion of conversion coatings and primers. Do NOT use in enclosed areas where
they can not be washed away.
✔✔Conversion Coatings - ✔✔Follows the metal conditioners and lays down a zinc
phosphate layer that maximizes primer adhesion as well as preventing rust "creep"
under the painted surface. Not to be used in enclosed sections.
✔✔Epoxy Primers - ✔✔Provides a level of corrosion protection closest to that of the
original E-Coat primer. Must be applied soon after the cleaning, etching and conversion
steps.
✔✔Induction Period - ✔✔Some epoxy primers need to sit for a time after mixing.
✔✔Self Etching - ✔✔Eliminates the need for conditioners and conversion coatings.
Must be top coated with a paint finish or anti corrosion compound.
✔✔Weld-Thru Primers - ✔✔Restores the zinc protection that is burned away welding.
Bonds tightly to bare metal and flows back into the weld site as it cools. Primers and
seam sealers do not adhere to it so it must be removed.
✔✔Seam Sealers - ✔✔Need to be replaced in any location that the manufacture
applied them to. Same as what was used, and should be applied after the epoxy or self
etching primers.
✔✔Wax and Petroleum Based Anti-Corrosion Compounds - ✔✔Applied to all enclosed
sections and underbody surfaces.
✔✔Sacrificial Corrosion - ✔✔Seal sacrifices itself against the elements.
✔✔Galvanic Corrosion - ✔✔When 2 metals react to each other. Replace any special
washers, films, gaskets to separate the two metals.
