C33 Surface Preparation for Various Substrates 2

Question 1

Before painting new galvanized steel, what surface preparation issue must a C-33 contractor address?

Accepted Answer

Zinc oxide and oils from the galvanizing process prevent paint adhesion

Answer

The surface is too rough for paint

Answer

Galvanized steel cannot be painted

Answer

The surface must be sand-blasted to bare steel

Question 2

What is the recommended method for testing surface moisture content in concrete before painting?

Accepted Answer

ASTM D4263 plastic sheet test or electronic moisture meter

Answer

Visual observation of color

Answer

Touching the surface with bare hands

Answer

Waiting a standard number of days after pouring

Question 3

When preparing previously painted exterior wood for repainting, what level of surface preparation is typically required?

Accepted Answer

Remove only loose, flaking paint; feather edges and sand glossy areas

Answer

Complete paint removal to bare wood

Answer

No preparation if the existing paint is in good condition

Answer

Apply new paint directly over any existing condition

Question 4

What is the purpose of applying an 'etch primer' to smooth, non-porous surfaces like aluminum or fiberglass?

Accepted Answer

To chemically etch the surface and create microscopic adhesion points for the topcoat

Answer

To add color to the surface

Answer

To make the surface waterproof

Answer

To fill large surface imperfections

Question 5

A C-33 contractor is preparing drywall with multiple joint compound patches. What preparation ensures a uniform paint finish?

Accepted Answer

Prime the entire surface with a PVA drywall sealer to equalize absorption rates

Answer

Apply paint directly - patches will blend in

Answer

Only prime the patched areas

Answer

Sand the patches flush and paint without primer

Question 6

What does 'profile' mean in the context of surface preparation for industrial painting on steel?

Accepted Answer

The microscopic peak-to-valley roughness pattern created by abrasive blasting

Answer

The cross-section shape of the steel beam

Answer

The chemical composition of the steel alloy

Answer

The thickness of the existing paint system