Interior Paint Additives

Paint additives are important elements of top-quality paint. They are used to provide desirable properties that the paint might otherwise lack. Certain additives are designed to improve ease of application, enhance the appearance of paint or provide protective qualities. While many manufacturers include some additives in their paints, there are some additives that can be purchased separately and added to your existing paint. Before you learn about your paint additive options, use the following questions to focus in on the needs of your specific project:

• Have you already purchased paint for your project?
• If you already have the paint, what additives, if any, does it contain?
• Do you need improved flow and leveling?
• Does your paint resist the growth of mildew?
• Are you painting metals that may rust?
• Are you specifically concerned about odor, drying time or foaming?
  
  

Types and Applications

Most paints, especially high-quality paints, already contain some additives. If you’ve purchased the paint for your project, but it doesn’t have the additives you’re looking for, some can be obtained separately and easily mixed directly into most oil- or water-based paints. When shopping for paint, don’t be deterred by higher prices. Paint additives are a key component in pricing, and paints with premium additives will require a higher up-front investment. If you think that a lower-priced paint will save you money, don’t forget to factor in the cost of purchasing additives separately or the need to repurchase and reapply low-quality paints sooner. Additives with a protective element, such as mildewcides, can save you even more money and time by protecting surfaces from the harmful effects of mildew, mold and more.

Performance Additives: Some of the more common additives include thickeners, mildewcides, surfactants, antifoam agents and corrosion inhibitors. Each of these additives is designed to address a different issue. Some combination additives are also available, such as conditioner/corrosion inhibitor. Conditioner is often applied to additives that enhance the workability, finish and performance of paint.

• Floetrol (for water-based paints) and Penetrol (for oil-based) are some of the most common paint conditioners
• Even on interior surfaces not subject to frequent moisture, mildewcides are important to prevent the growth of mildew
• If you’re painting metal that rusts, including nail heads, look for a primer or paint with a corrosion inhibitor

Additive	What You Should Know
Antifoam Agents	Break or prevent bubbles Particularly important when applying paint with a roller
Biocides	Include additives that control mold, mildew, fungus, insects and more Mildewcides are very important, even in rooms with “normal” humidity Higher levels of mildewcides are generally reserved for high-quality paints Also include preservatives that prevent the growth of bacteria in the paint can
Corrosion Inhibitors	Help prevent the oxidation (rusting) of ferrous metals, as well as resulting blistering, peeling and rust bleed-through For painting surfaces with metal fasteners (nails, screws, etc.) in addition to all-metal surfaces
Floetrol	Conditioner for water-based paint Reduces brush marks and bristle separation Permits 20% lower spray pressure when spraying Performs well in hot weather
Penetrol	Conditioner for oil-based paint Reduces paint peeling on wood and metal Makes an ideal matte finish for interior rustic woods Restores luster to faded fiberglass
Rheology Modifiers (Thickeners)	Provide better application properties and better paint appearance Enhance the flow and leveling of paint and provide better film build, which improves hiding and durability
Surfactants	All water-based paints have surfactants Reduce surface tension to improve wetting Help disperse pigments for better coverage Prevent the paint from crawling on the surface Stabilize paint to prevent separation or thickening Provide compatibility with tinting agents

Other Additives: There are a variety of specialty additives, so, if you have a specific painting concern, it’s worth checking to see if a useful additive exists. There are additives that reduce paint odor, change the sheen, provide better freeze/thaw stability and more. Additives that increase or decrease drying time can make painting a lot more convenient. You can speed up the drying time of an oil-based paint if you want to be able to apply a second coat sooner, or you can slow down the drying time of water-based paint for better leveling or when working in direct sunlight.

• A variety of additives are available to tackle situation-specific problems
• Odor reducers keep paint odors to a minimum without affecting other paint properties
• Drying retardants and enhancers change the drying time according to your needs
  
  

Features

Low VOCs: VOCs are volatile organic compounds that can be dangerous to humans and the environment. Many paint additives and paints, especially oil-based paints, contain VOCs. Look for additives with low VOCs for your own safety and that of the environment.

Nonskid Additives: Nonskid paint additives are gritty additives used to make painted floors less slippery.