Outdoor Additive | Knot Blocker – Exterior Additive for Real Milk Paint®
Outdoor Additive is a finely milled borate-based compound designed to enhance the performance of Real Milk Paint® on exterior wood, masonry, and other porous surfaces. When dissolved and mixed into the paint, it helps reduce tannin bleed-through from knots, improves mold and mildew resistance, and boosts long-term outdoor durability. This additive ensures a smoother, more stable film while maintaining the natural, breathable qualities of milk paint.
Key Benefits
- Blocks Tannins & Knot Discoloration: Helps prevent stains from cedar, knotty pine, and other tannin-rich woods from migrating through the paint.
- Improves Exterior Durability: Strengthens Real Milk Paint® for outdoor use, offering better resistance against weathering.
- Mold & Mildew Resistance: Borate compounds help inhibit mold and mildew growth when used at recommended levels.
- Enhances UV Stability: Helps protect the paint film from UV degradation, keeping exterior surfaces looking fresh longer.
- Non-Toxic & Easy to Mix: Made from safe borate compounds that dissolve smoothly into water before blending with powdered milk paint.
Suitable Uses
- Exterior Wood: Ideal for clapboards, fencing, siding, trim, shutters, and outdoor furniture.
- Historic Restorations: Supports period-appropriate finishes on homes from the 1800s and early 1900s.
- Porous Surfaces: Can be used on unpainted masonry such as brick, stucco, and concrete.
- Knotty or Tannin-Rich Woods: Helps manage bleed-through on cedar, redwood, fir, and pine.
- Outdoor Projects with Milk Paint: Ensures Real Milk Paint® performs well outdoors when paired with a protective topcoat like Outdoor Defense Oil.
Packaging
Outdoor Additive comes in a 1-cup resealable container, finely milled for easy dissolving and smooth mixing with Real Milk Paint®. The compact size is convenient for storage and accurately portioned for use with pints, quarts, or gallons of paint.
Coverage & Sizes
| Size |
Recommended Use |
Mixing Ratio |
| 1 cup (per package) |
Suitable for 1 gallon of Real Milk Paint® |
Mix 1 cup additive into 10 cups of water |
| ¼ cup |
Suitable for 1 quart of Real Milk Paint® |
Mix ¼ cup additive into 2.5 cups of water |
| ⅛ cup (2 tbsp) |
Suitable for 1 pint of Real Milk Paint® |
Mix ⅛ cup additive into 1.25 cups of water |
Directions for Use
How to Use Outdoor Additive Knot Blocker
- Dissolve Additive: Measure the correct amount of Outdoor Additive and dissolve it fully in warm water according to your paint quantity (see Coverage & Sizes table).
- Prepare Surface: Ensure the exterior surface is clean, dry, and free from existing paint or finishes. Real Milk Paint® will not bond correctly over modern paint films.
- Mix with Milk Paint: After the additive has completely dissolved, combine the mixture with powdered Real Milk Paint®. Stir or blend thoroughly until smooth.
- Apply Paint: Brush or roll the mixed paint onto the surface, ensuring even coverage. Avoid overworking the paint to maintain a consistent film.
- Allow Drying: Let each coat dry thoroughly before applying the next. Outdoor Additive enhances exterior durability but does not change basic milk paint dry times.
- Topcoat for Protection: For improved water resistance and long-term durability, apply Outdoor Defense Oil after the final coat of paint has cured.
Hints & Tips
- Dissolve Fully First: Always dissolve Outdoor Additive completely in water before mixing with powdered Real Milk Paint®; this ensures a smooth, even finish.
- Use on Bare or Porous Surfaces: For best adhesion, apply only to unpainted wood, brick, stucco, or concrete. Remove modern paints before use.
- Stir Thoroughly: Blend the additive mixture and milk paint well to prevent settling and ensure optimal exterior performance.
- Avoid Overworking the Paint: Brush in smooth, consistent strokes. Excessive brushing may disrupt the paint film.
- Protect with a Topcoat: For durability and water resistance, finish exterior projects with Outdoor Defense Oil.
- Test on Tannin-Rich Woods: When working with cedar, redwood, or knotty pine, apply a small test area to confirm stain-blocking performance.
Why Choose Outdoor Additive
- Borate-Based Formula: Made from finely milled borate compounds known for their long-standing use in exterior wood protection.
- Enhances Outdoor Durability: Strengthens Real Milk Paint® for exterior conditions, helping resist UV exposure, mold, and mildew.
- Reduces Tannin Bleed-Through: Helps prevent knot stains and discoloration from showing through the paint film.
- Consistent, Smooth Mixing: Dissolves easily in water and blends seamlessly with powdered Real Milk Paint®.
- Safe and Non-Toxic: Borate compounds are safe to handle and commonly used in household applications.
- Trusted for Historic and Modern Projects: Ideal for restorations, exterior siding, fencing, and any outdoor milk paint application.
FAQs
Can I use Outdoor Additive Knot Blocker with any type of paint?
No. It is formulated specifically for Real Milk Paint® and should not be added to modern acrylic or latex paints.
Does this additive make milk paint waterproof?
No additive can make milk paint fully waterproof. Outdoor Additive improves durability and resistance, but a protective topcoat like Outdoor Defense Oil is recommended.
Will it stop all tannin bleed-through?
It significantly reduces tannin and knot stains, especially on woods like cedar or knotty pine, but extreme cases may still require multiple coats or a light test patch.
Is it safe to use around people and pets?
Yes. The borate-based formula is considered non-toxic when used as directed.
Can I mix Outdoor Additive with other Real Milk Paint additives?
Yes. It can be used alongside pigments or other additives as long as each is dissolved and mixed according to its instructions.
