There are lots of myths out there about wood varnish. As a homeowner, if you need to know how to varnish, you need to know a little bit about varnish. That way you won't get hood-winked and can do the job right.
You'll seldom find factory or professionally finished cabinets that have varnish on them.
WHY? The reason is not that varnish is an inferior product, but it creates a sticky mess when you spray it on (which is what professionals like to do to save time - spray finishes on).
Varnish also dries slowly. What does that mean for you? When you brush it on, your piece is going to be susceptible to dust because of it's slow cure time. If your piece dries with dust on it, or in the finish, you'll have to take the dust off. You do this by scuffing (or lightly sanding) the piece between coats of finish.
This certainly isn't impossible to do, but the more dust that settles in your finish, the more time it takes to scuff it out, and it may even mean more coats of finish for your piece to look right.
WHAT'S POLYURETHANE THEN? IS IT VARNISH OR NOT?
Polyurethane has become a finish onto itself, although it is really a varnish resin. Go to ourPolyurethane page from our Wood Varnish page for more specific information on polyurethane.
On this page, will focus on the other two types of resin used for varnish - Phenolic and Alkyd. These two are what's more traditionally known as wood varnish.
7 PROPERTIES OF WOOD VARNISH
- Varnish is resistant to heat and alcohol (more so than shellac and lacquer).
- Varnish is resistant to wear and solvents.
- It is water and water vapor resistant (resistant to humidity).
- It has a long curing time (slow to dry).
- It's long curing time makes it easy to brush, but can cause problems with dust getting into the finish.
- It tends to yellow more over time than other finishes, especially the Phenolic resin type.
- Varnish cures by being exposed to oxygen. When left in a can that has air in it, it will skin over in time. If the varnish hasn't begun to gel under the skin, it's still okay to use. Remove the skin and strain the remaining varnish into a smaller can (or glass jar), and seal.
3 TYPES OF WOOD VARNISHES
There are several different brands of varnishes, with multitudes of names and properties touted on the can. Don't be confused by them when you are learning how to varnish wood. There are really only three basic resins used to make varnish, each with slightly different properties and uses.
It's good to discuss with your supplier what they recommend for you to use, but here are the guidelines and basic things to know about wood varnish:
Varnish is a combination of oils and resins. At one time it was only made with natural oils (like linseed or tung oil) and natural oil resins. Today, oils are still used but the resins are synthetic. Doing this actually makes for better varnishes than years ago.
A system of calling varnishes short-oil, medium-oil, and long-oil developed. How much oil is added to the resin determines whether it is a short-oil, etc.
HOW VARNISHES ARE CATEGORIZED BY THEIR OIL CONTENT:
- Have a low % of oil in them.
- They are hard, so they'll withstand abrasion well.
- They are also (in their natural state) glossy.
- Short-oil varnishes are used to varnish kitchen cabinets.
- Have a low % of oil in them, but more than short-oil varnishes.
- They are a little less durable than short-oil varnishes.
- They are a little bit less glossy than short-oil varnishes.
- A medium-oil varnish could also be used to varnish kitchen cabinets.
- Are not used to varnish kitchen cabinets.
- They have a much greater % of oil in them.
- They dry very slowly.
- They have a soft and elastic (flexible) coating.
- Long-oil varnishes are commonly sold as "spar" or "marine" varnishes.
- They are intended to be used for outdoor wood applications. WHY? Wood that is outside will expand and contract much more than wood that is inside (just because of the elements) thus the need for flexibility.
WOOD VARNISHES ARE ALSO CATEGORIZED BY THE RESIN USED
Varnishes are further categorized by what type of synthetic resin is used in making them. There are basically three types, Phenolic, Alkyd, and Polyurethane.
Phenolic resin, a synthetic resin, can be for outdoor use, such as when it is combined with tung oil to make a spar varnish. It will be durable and flexible, but it yellows significantly. It can also be used as a rubbed varnish for indoor furniture, such as table tops, when not as much oil is added. It is used little today, and you wouldn't use it to varnish kitchen cabinets.
Alkyd resin is a type of polyester developed in the 1920's. Alcohol and acid are used to make this resin (and a bit of oil) thus the name. It is less expensive than phenolic resin varnish, and it is the most common resin found in varnishes (it is also used in lacquer and conversion finishes).
Polyurethane Resin - Go to our Polyurethane page from our Wood Varnish page.
Return to our Kitchen Cabinet Finishes page.
Go to ourHow To Varnish Page to learn the 6 easy application steps.
And remember - HAVE A HAPPY KITCHEN!!!
OTHER RELATED SITES:
Cleaning Kitchen Cabinets - Take note & make use of these easy observations before you clean.
Cleaning Wood Kitchen Cabinets - It's Easy - you don't need "secret" cleansers or be a pro. This page tells you how!
Home Improvement Resources - Some neat sites we've run across. Kitchen Cabinets, Hardware, Remodeling, Lawn Care - find it all.
How to Stain Kitchen Cabinets - 6 easy steps & 13 things you must have BEFORE you start.
How to Varnish Wood - 7 properties, 3 types, 6 application steps to follow - Helping you keep it all STRAIGHT!!
Ideas for Painting Kitchen Cabinets - 4 really simple and useful ideas to make your life easier (plus a couple of variations).
Kitchen Cabinet Finishes - From lacquer to water based. What's really right for you? (and what's just plain out-dated)
Kitchen Cabinet Finishing - Do you homework BEFORE you finish or refinish & you'll have an easy time of it.
Polyurethane Varnish - The "varnish" that works fast and furious. Tips and Tricks.
Repaint Kitchen Cabinets - Yes, you can repaint your kitchen cabinets in 5 easy steps.
Staining Kitchen Cabinets - Your Time, Your Success - Tips You Must Know.
Water Based Cabinet Finish - Pros, Cons, How to apply it so it lasts!!