When a stain or wood finish is first introduced to bare wood it comes to life. You finally see the beauty of the wood. The finish you choose not only protects your project but can highlight the beautiful grain patterns or can be used to hide flaws. these tips hold true for new woodworking projects as well as furniture refinishing.
The first step in wood finishing is getting the surface prepared properly for the dye, stain, or top coat of your choosing by sanding the wood smooth.
The second step is choosing the the finish you want for your project.
If you followed one of my recommendations of wetting the wood between sanding then you have a pretty good idea of what the wood will look like with a clear finish on it. Another option is wetting the wood with a little paint thinner to see if this would be the finish you will be happy with or you may need to choose a stain if it's not dark enough.
If clears your route then are a few choices I've used.
Polyurethane Lacquer Shellac Varnish Tung Oil
This is a good choice for furniture that needs protection from everyday use. It is moisture resistant, so you can set glasses on it without worrying about ring marks.
Poly comes in a gloss, semi-gloss and satin luster. It also comes in clear or amber colors. Dries slowly and has a harsher odor than water-based formula.
Water-based poly will not yellow like oil-based poly. Comes in a gloss and satin luster. It's advantages are moisture resistance, it dries faster than oil- based poly and has low odor.
I use polyurethane for any items requiring a more durable finish. I apply it with a foam applicator (use one suitable for oil-based finishes) and I have actually diluted the oil-based with mineral spirits and sprayed on with a spray gun. Whether sprayed or brushed on, I sand between coats with 220 grit sandpaper.
You can make your own wiping varnish with poly by diluting with either mineral spirits or water, depending on which poly you are using. Advantages to this method: speedier dry time and with fewer coats it can look like an "old time" finish. Drawback: it isn't as durable as regular application, due to thickness.
I use lacquer on most projects I build or refinish. It dries quickly and clear. I buy my lacquer from my local home improvement store. On the can it is called "brushing lacquer". I dilute it with a little lacquer thinner and apply with a spray gun. You can usually re-coat in 5-10 minutes without sanding between coats.
You can actually touch the finish with your hand in 5-10 minutes. One disadvantage can be the fast dry time on humid days, because it dries so fast it can actually trap moisture in the finish, leaving white, cloudy spots that will need to be sanded out. You can by a drying retarder that remedies this by slowing dry time.
This finish is found on a lot of older furniture. I have only used it on very few occasions to match finishes. It dries quickly but doesn't wear well and is affected by water (i.e. drinking glasses left on table). You can get clear shellac but most has an amber tint. Varnish This amber colored, slow drying finish comes in a gloss, semi-gloss and satin luster. It is decently durable and moisture resistant.
Easily available. Dries slowly. Satin luster. Not a good finish if you require moisture resistance. Must recoat frequently.