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Minwax® Helmsman® 350 VOC Spar Urethane

Minwax® Helmsman® 350 VOC Spar Urethane

Helmsman® 350 VOC Spar Urethane is a specially formulated protective clear finish for exterior or interior wood that is exposed to sunlight, water, or temperature changes. This clear protective finish for wood contains UV blockers to reduce the sun's graying and fading effects. Helmsman® 350 VOC Spar Urethane forms a protective barrier against rain and moisture and its special oils allow the finish to expand and contract with the wood as seasons and temperatures change.

Helmsman® 350 VOC Spar Urethane is not recommended for use on floors.

Product Details

Sheens: Gloss, Semi-Gloss, Satin
Application Tool: natural bristle brush
Location: interior and exterior wood surfaces
Recoat: after 6 hours
Dry time: 24 hours
Cleanup: mineral spirits
Coverage: 100 sq. ft. per quart
Coats: 2-3
VOC Content: maximum VOC of 350 g/L
Recommended Uses: doors, windows, bathroom cabinets, bar tops, kitchen countertops and outdoor furniture
Availability: not available in California


Q. How does Helmsman® 350 VOC Spar Urethane differ from other polyurethanes?

Helmsman® contains special ultraviolet absorbers to help protect wood from the graying and fading effects of the sun. Helmsman® also contains special oils that allow it to expand and contract with seasonal temperatures changes.

Q. Can Helmsman® be used on interior floors?

No. Helmsman® is formulated to expand and contract with temperature changes. Because it is flexible, it is not suitable for use on floors. Floors require a harder finish such as Minwax®  Fast-Drying Polyurethane, Minwax® Super Fast-Drying Polyurethane for Floors or Minwax® Water-Based Polyurethane for Floors.

Q. Should Helmsman® 350 VOC Spar Urethane be applied to exterior furniture?

Yes, but no clear exterior finish will permanently protect wood against direct sun, snow, ice and rain. Be sure to check the finish annually to determine if it needs to be recoated. If the finish warrants, apply an additional coat of Helmsman® according to the label directions.

Q. Is Helmsman® suitable for decks and fences?

No. Decks and fences have special requirements for protection against the elements. Use an exterior waterproofing product such as Thompson's® WaterSeal® Waterproofer Plus Clear Wood Protector.


  1. Surface must be dry and free of paint, wax, grease, polish, old finishes in poor condition or any foreign matter.
  2. Sand to obtain a smooth, uniform surface. Remove all dust with a damp cloth.
  3. If desired, apply stain, such as Minwax® Wood Finish™, to unfinished interior wood surfaces. Follow directions for application instructions and dry times.
  4. Stir well before and occasionally during use.
  5. Apply a thin coat of Helmsman® 350 VOC Spar Urethane using a high quality natural bristle brush. On unfinished wood, apply sufficient material to seal open joints, edges and end-grain.
  6. Let dry at least six hours, then sand entire surface lightly with very fine sandpaper (220 grit) to ensure an even finish and proper adhesion of additional coats.
  7. Apply second coat. If a third coat is desired, repeat Step 6 before applying. Note: For exterior surfaces or for previously unfinished wood, three coats are recommended.
  8. After final coat, allow 24 hours before normal use.

Clean Up: For easy clean-up use mineral spirits or paint thinner.

Coverage: Approximately 100 sq. ft. per quart

Note: Dry times are based on good ventilation, temperature of 77°F and 50% relative humidity. Lower temperature, higher humidity, lack of air movement or application of thick coats will extend drying times. Always test surface for tackiness between coats. When used for exterior applications, maintain by lightly sanding and adding an additional coat(s) as conditions require.

Helmsman® 350 VOC Spar Urethane is not recommended for large exterior surfaces where maintenance would be difficult, such as decks and siding. Slight ambering may be experienced when Helmsman® 350 VOC Spar Urethane is applied over light-colored stains or wood surfaces. Always spot test on an inconspicuous area to ensure satisfactory results.