BlueCollarBench

Trades/Painting & Finishing

Painting & FinishingTask PA-033journeymanCatchUS

Painter is doing a 1962 ranch house exterior.

Prompt as given to every model

Painter is doing a 1962 ranch house exterior. He sets up a gas-powered pressure washer at 3,000 psi with a 15-degree tip and blasts all the alligatored old paint off the wood siding, letting it fly into the flower beds. Then he plans to hand-scrape the rest and repaint. What's the problem?

Model answers

Pick up to two to compare side by side. Score chips fill in as the judge grades.

Nemotron 3 Ultra 550BScore —

Three major problems:

  1. Lead Paint Hazard (Pre-1978): A 1962 house almost certainly has lead-based paint. Blasting it at 3,000 psi with a 15° tip atomizes lead into dust and chips, contaminating soil (flower beds), air, and the structure. Violation: EPA RRP Rule (40 CFR 745.85) prohibits power washing/pressure washing that creates dust/chips without containment. Requires Certified Renovator and Lead-Safe Work Practices (plastic sheeting 10 ft out, vertical containment, HEPA vac). Liability: You own the contamination. Soil remediation costs $10k–$100k+.
  1. Substrate Destruction: 3,000 psi + 15° tip on 60-year-old wood erodes soft grain, drives water deep into sheathing/studs, and fractures siding. This causes rot, peeling new paint, and mold. Max for wood prep: 500–800 psi, 25–40° tip, 12–18" distance.
  1. Improper Sequence: You don't blast then scrape. You scrape/HEPA sand first to remove loose paint, then low-pressure wash to clean dust/chalk, then prime bare wood within 24 hrs.

Correct Protocol:

  1. Test for lead (EPA-recognized kit or XRF).
  2. If lead: Hire EPA RRP Certified Firm. Set containment (6-mil poly, weighted edges). Manual scrape/HEPA sand. HEPA vac. Low-pressure rinse (≤800 psi). Collect all wastewater/chips.
  3. If no lead: Manual scrape → 500–800 psi/40° tip wash → dry 3+ days → prime bare wood → paint.
  4. Never let debris enter soil. Use tarps/disposal per 40 CFR 745.85(d).

Stop this painter immediately. They are creating a Superfund site in the yard and ruining the siding. Require RRP certification proof before restart.

642 tokens · 12.7s

Judge rubric · pending

Not graded yet. Grading starts when the exam run completes.

Nemotron 3 Super 120BScore —

The painter’s approach is unsafe, environmentally harmful, and likely violates multiple codes and best practices.

Problems:

  1. Lead Paint Hazard (Critical): A 1962 house almost certainly has lead-based paint (banned in 1978). Blasting it at 3,000 psi with a narrow 15-degree tip creates airborne lead dust and chips, contaminating soil, air, and water. This violates EPA’s Renovation, Repair and Painting (RRP) Rule (40 CFR Part 745), which requires containment, HEPA filtration, and certified workers for pre-1978 homes. Letting debris fly into flower beds risks poisoning soil, plants, groundwater, and anyone (especially children) who contacts it.
  1. Surface Damage: 3,000 psi with a 15-degree tip is excessive for wood siding. It will gouge, splinter, or erode softwood (common in 1960s ranch homes), damaging the substrate and reducing paint adhesion. Recommended pressure for wood is ≤1,500 psi with a 25–40° fan tip and proper distance.
  1. Environmental Contamination: Paint chips and washwater containing lead, solvents, or biocides are hazardous waste. Discharging them into flower beds violates the Clean Water Act and local stormwater regulations. Must be collected and disposed of as hazardous waste.
  1. Incomplete Preparation: Pressure washing alone doesn’t remove all failed paint—especially in cracks or underlap. Hand-scraping is needed, but only after safe, contained removal.

Correct Approach:

  • Test for lead (EPA-recognized kit or lab).
  • If positive, hire an EPA-certified lead-safe contractor.
  • Use containment (plastic sheeting, negative air), HEPA vacuums, and low-pressure washing (<1,500 psi) with proper collection.
  • Dispose of waste per RCRA/hazardous waste rules.
  • Only then scrape, sand, prime, and repaint.

Bottom line: This method is illegal, dangerous, and irresponsible. Stop work immediately and consult a certified lead abatement professional. (OSHA 1926.62, EPA RRP, IRC R317.1, ASTM D4258)

654 tokens · 7.3s

Judge rubric · pending

Not graded yet. Grading starts when the exam run completes.