Finishes

Water-Based Finishes

Water-based finishes require fewer coats, are non-flammable, dry fast, and easy to clean up.  They are safer for you and the environment than traditional finishes.  Water-based finishes are sensitive to weather and may raise the grain of the wood.  Water-based finishes contain numerous products that help with flow and leveling, control drying, and reduce foaming.  These additives can be toxic, but the amount is much less than contained in traditional finishes.

Water-based finishes are composed of:

  • Resin: The resin forms the final film.  Water-based products currently consist of one of three types of plastic resins: acrylic, urethane, or a mixture of those.
  • Water: The liquid vehicle in which the resin is suspended.
  • Additives:
    • Co-solvents soften the resins and allow them to stick together, the most common chemical co-solvent used are alcohols called glycol ethers.
    • Tail Solvents- slow drying alcohols that remain with a coating for a relatively long time in its applied state.  Used to improve flow and leveling and help in maintaining a wet edge during application.
    • Surfactants- Usually petroleum-based products that are added to reduce surface tension, helping to improve the finishe's ability to flow and level smoothly.
    • De-foamers- Reduce the amount of foam in a finish.
    • May also contain leveling agents, wetting agents, fungicides, mildicides, pigments, soaps, hardeners, thickeners, and binders.
  • Glycol Ethers- very slow-drying alcohols that are totally capable of being mixed with water.  As the water evaporates, the slower-drying glycol ether is left behind to soften the resins so they can coalesce.  Scorecard classifies glycol ethers as suspected:
    • Cardiovascular or Blood Toxicant
    • Developmental Toxicant
    • Gastrointestinal or Liver Toxicant
    • Kidney Toxicant
    • Neuro Toxicant
    • Reproductive Toxicant
    • Respiratory Toxicant
    All of that being said, Water-based finishes are still a better alternative to standard finishes.

Linseed Oil

Natural Linseed oil dries very slowly, and may never dry completely.  To speed drying time, Boiled Linseed Oil was developed.  Chemicals are added to speed drying time of the oil.  This wording was taken from a label of boiled linseed oil:  "Use of this product will expose you to arsenic, beryllium, chromium, cadmium, and nickel, which are known to cause cancer, and lead which is known to cause birth defects and other reproductive harm."