How long should I wait between coats of polyurethane?
Recoat within 2 hours. If unable to do so, wait a minimum of 72 hours, then lightly sand and recoat. Apply at least three coats on unfinished wood and two coats on surfaces already finished. After final coat, allow 24 hours before normal use.
Use undiluted polyurethane varnish straight from the can for the second and third coats. After you've wet the entire surface, go back and overlap each stroke across the entire surface, following the direction of the grain. Within 24 hours of applying your seal coat, brush on a coat of finish right from the can.
- Method 2 Using Sealants to Waterproof
- Prepare the surface. You'll need to remove any remaining trace of past finish before using a sealant.
- Purchase a water-based wood sealer.
- Apply an even coat.
- Allow the product to dry.
- Clean the first coat.
- Apply a second and third coat.
- Give the wood time to cure.
- The only way to make wood waterproof is to burn it. Seriously, polyurethanes will help make wood water-resistant but not waterproof. It will slow down, but not stop, water intrusion. Nothing stops water intrusion into wood, or totally prevents wood respiration.
- Actually, well-manufactured polyurethane is no danger at all. Its dangerous components are rendered inert or non-toxic if successfully bonded. One main ingredient, the cause of polyurethane dangers is isocyanates.
Spread oil-based polyurethane with a lambswool applicator. Brush the applicator with a stiff hair brush to remove stray fibers before using it. Use a foam or synthetic fiber applicator for water-based polyurethane.
- Spread oil-based polyurethane with a lambswool applicator. Brush the applicator with a stiff hair brush to remove stray fibers before using it. Use a foam or synthetic fiber applicator for water-based polyurethane.
- Minwax® Helmsman® Spar Urethane is specially formulated as a protective clear finish for exterior or interior wood exposed to sunlight, water, or temperature changes. Contains UV blockers to reduce the sun's graying and fading effects. Forms a protective barrier against rain and moisture.
- Tack cloth (tack rag; tac cloth) is a specialized type of wiping cloth that is treated with a tacky material. It is designed to remove loose particles of dust, dirt and lint that would contaminate a surface that is to be painted, coated, laminated, photo-etched, or otherwise finished.
Updated: 12th November 2019