NCCER Painter cheat sheet

Theoretical coverage (sq ft/gal) = 1,604 × (% solids by volume ÷ 100) ÷ dry film thickness in mils; at 100% solids and 4 mils DFT, coverage is about 401 sq ft/gal.

Wet film thickness = dry film thickness ÷ (% solids by volume ÷ 100). Example: 2 mils DFT at 50% solids requires 4 mils WFT.

1 mil = 25.4 micrometers (microns); 1 gallon = 3.785 liters; 1 square meter = 10.764 square feet.

OSHA construction fall protection is required at 6 feet or more above a lower level; guardrails, safety nets, or personal fall-arrest systems are acceptable.

Extension ladders: set the base 1 foot out for every 4 feet of working height; the ladder angle is about 75.5 degrees.

A 3-4-5 triangle establishes a 90-degree corner; multiples such as 6-8-10 work the same way.

SDS has 16 sections; Section 2 gives hazard identification, Section 4 first-aid, Section 8 exposure controls, and Section 9 physical properties.

VOC content (g/L) = mass of volatile organic compounds in grams ÷ volume of coating in liters.

Confined-space entry requires atmospheric testing for oxygen, flammables, and toxics before entry and continuous ventilation or supplied air as required.

SSPC surface-preparation standards: SP 1 solvent cleaning, SP 2 hand-tool cleaning, SP 3 power-tool cleaning, SP 5 white-metal blast, SP 6 commercial blast, and SP 10 near-white blast.

Abrasive blast profile is measured in mils with a surface comparator or replica tape; a typical profile for many industrial coatings is 1.5–3.0 mils.

New concrete should cure about 28 days and be tested for moisture and pH; many coatings require pH 10 or below and moisture vapor emission within the manufacturer's limit.

Wood moisture content should generally be 12–15% or less before painting; verify with a moisture meter.

Galvanized steel: remove oil and dirt, then etch or use a galvanized-compatible primer; direct application of alkyds can fail from poor adhesion.

Mildew: wash with a bleach/detergent solution, rinse, and allow to dry; dead mildew must be removed, not just painted over.

Drywall: embed tape in setting-type compound, sand smooth, remove dust, and prime with a drywall primer before finish coats.

Ferrous metal: remove rust and mill scale by SSPC-SP 2, SP 3, or blast cleaning; apply primer before visible rust returns.

Glossy surfaces should be sanded or deglossed so the new coating can form a mechanical bond.

WFT = DFT ÷ (% solids by volume ÷ 100); if a coating is 60% solids and 3 mils DFT is specified, apply 5 mils WFT.

Waterborne acrylics clean up with soap and water, have low odor and VOC, and remain flexible; solventborne alkyds clean with mineral spirits and can yellow.

Two-component epoxies have a pot life and a recoat window; the mixing ratio must be exact, and amine blush must be removed before recoating.

Shellac is a stain-blocking primer for knots, water stains, and tannin bleed; alkyd or water-based stain blockers are alternatives.

Zinc-rich or zinc phosphate primers protect ferrous metal; incompatible topcoats can cause blistering or poor adhesion.

Colorant tints are added in drops or measured units; tinting strength varies by pigment, so add small amounts and test the color.

Metamerism occurs when two colors match under one light source but differ under another; evaluate color under the specified lighting.

Sheen levels: flat has low angular sheen and hides surface defects; semigloss and gloss are more washable and highlight imperfections.

Primer/sealer selection: alkali-resistant primer for masonry, stain-blocking primer for knots or nicotine, and bonding primer for glossy or difficult surfaces.

Natural-bristle brushes are for solventborne coatings; synthetic filaments are for waterborne coatings because natural bristles absorb water and soften.

Roller nap: 1/4–3/8 inch for smooth surfaces, 1/2–3/4 inch for light texture, and 3/4–1 inch or more for rough masonry.

Airless spray tip orifice is measured in thousandths of an inch; a larger orifice and higher pressure increase flow, while a smaller orifice gives a finer finish.

Airless sprayer: keep the gun 12–18 inches from the surface, hold it perpendicular, and overlap each pass by about 50%.

HVLP sprayers use high volume and low pressure; transfer efficiency is typically higher and overspray lower than conventional air spray.

Zahn cup viscosity is measured in seconds; the time to drain indicates whether the coating needs thinner.

Back-roll or brush out sprayed edges and corners to blend the finish and prevent dry spray or lap lines.

Tip wear enlarges the orifice and increases flow; replace tips when the fan pattern or coverage changes.

Do not mix coatings with different solvents or cure mechanisms without manufacturer approval; incompatible thinners can gel or curdle.

Wallcovering strip count = wall perimeter ÷ usable roll width; roll yield = roll length ÷ cut length; add 10–15% for pattern matching and waste.

Pattern match types: straight match aligns repeats horizontally; drop match offsets alternate strips; random match needs no alignment.

Priming wallcovering: use a wallcovering primer/size that is compatible with the paste and allows future stripping.

Wallcovering paste types: wheat paste for paper, clear vinyl-over-vinyl adhesive for vinyl, and heavy-duty clay-based paste for heavy goods.

Faux finishes: sponging, ragging, color washing, strié, and marbling are decorative techniques applied over a base coat.

Venetian plaster is a lime-based plaster applied in thin layers and burnished to a polished finish.

Metallic coatings and glazes need uniform application and controlled overlap to avoid lap marks and uneven sheen.

Wallcovering removal: perforate or score the surface and soften the adhesive with steam or an enzyme stripper before pulling to reduce drywall damage.

Stenciling requires low-tack stencil adhesive and a dry brush or roller to prevent bleed under the stencil.

Labor hours = area ÷ production rate (sq ft per hour), then add a waste or difficulty factor for surface and access.

Paint gallons per coat = area ÷ coverage per gallon; multiply by number of coats, then add 5–10% waste.

Markup = (selling price − cost) ÷ cost; margin = (selling price − cost) ÷ selling price; they are not the same percentage.

Labor burden includes payroll taxes, insurance, benefits, and workers' compensation; it is added as a percentage of base wages.

Airless sprayer flow rate is rated in gallons per minute; tip size, pressure, and material viscosity determine actual delivery.

Compressor sizing: CFM at the spray gun's required pressure must be available at the gun, not just at the tank.

Supported scaffold height-to-base ratio should not exceed 4:1 unless designed by a qualified person; use guardrails and proper access.

A change order should be documented before work proceeds: scope, price, schedule impact, and customer approval.

Job cost includes direct materials, direct labor, equipment, and subcontractors; overhead and profit are added separately.