CSLB C-33 Painting & DecoratingCoating ApplicationEasy
A painting contractor is preparing to apply a water-based acrylic latex paint to a newly primed interior wall. The manufacturer's instructions specify a maximum thinning of 10% by volume if necessary for spray application, but advise against thinning for brush or roller application. The contractor plans to use a roller for this project. What is the most appropriate action regarding thinning the paint?
- AThin the paint by 5% with water to improve flow and reduce roller marks, as this is within the manufacturer's maximum.
- BThin the paint with a small amount of mineral spirits to ensure better adhesion to the primed surface.
- CThin the paint by 10% with a paint conditioner to enhance leveling and extend open time.
- DApply the paint without thinning, as the manufacturer advises against it for roller application.
Show answer & explanationAnswer & explanation
Correct answer: D. Apply the paint without thinning, as the manufacturer advises against it for roller application.
Following manufacturer instructions is crucial for optimal paint performance and longevity. The instructions explicitly advise against thinning for roller application, making 'apply without thinning' the correct choice.
Why the other options are wrong
- A. This contradicts the manufacturer's specific advice against thinning for roller application, even if within the general maximum.
- B. Mineral spirits are not suitable for thinning water-based acrylic latex paint; water is the appropriate thinner if thinning were needed.
- C. Thinning by 10% is only for spray application, and using a paint conditioner (not specified by manufacturer for thinning) is inappropriate here.
Paint Thinning Guidelines
Always adhere to the paint manufacturer's specific thinning instructions, considering the paint type, application method, and environmental conditions.
- Thinning too much can reduce paint durability and coverage.
- Different paint types require specific thinners (e.g., water for latex, mineral spirits for oil-based).
- Manufacturer instructions are paramount for optimal results.
Memory trick: Read the label, then grab your water or paint thinner.