Saturday, August 29, 2009

What Woods Are Good for Building Outdoor Furniture?

In my last blog entry I talked about finishing outdoor furniture, then I realized that I hadn’t talked about what materials work well for these pieces. With that said, let’s jump in and cover that today.

Most woods do not work well out doors; they are prone to water damage, mold and fungus infection, and sun or UV degradation. These frequently lead to splitting and splintering which just lets the water, sun and microbes work its magic further into the wood. Paints and oil finishes delay this brake down but the upkeep of the finish on the wrong wood just delay’s the inevitable.

So if most woods don’t survive outside, which ones do, and why? The most readily available are the teak, cypress, mahogany and white oak families. Just to let you know, cypress includes redwood and cedar two popular exterior woods. Let’s look at these woods and what makes them special.

Teak contains natural oils that make it great for exterior uses. Not only do the oils protect the wood from water, but insects and pests too. Cypress, like teak, has natural oils that make it resistant to weather. Mahogany is also resistant to splintering and shrinkage, which makes it a good choice. White oak is rot resistant due to its particular cell structure. This structure, called tyloses, does not allow water to pass through the cell thus preventing the breakdown.

You may have noticed that pine isn’t in the list of good exterior woods. Most pines don’t do well out doors, they don’t have the oils or cell structure to fight off decay. One exception being southern long leaf pine, as that was prized for mast building. An option is pine that has been pressure treated (PT). This is a process where the chemicals are forced into the wood cells under high pressure, thus preventing rot. The down side to using pressure treated wood is that is usually unattractive, heavy and, oh yeah, filled with chemicals. PT is great for structural work, but not a great choice for furniture work.

So now you know what woods work well outside. Are there others, sure? Lots of exotics work well outdoors as well. The problem with most exotics is that they are expensive, and not always harvested under, shall we say, the best intentions? But that is a blog for another day.

Tuesday, August 18, 2009

What is a good finish for outdoor woodwork?

There are two things that effect exterior finishes considerably more than interior finishes: sun and water. Because of this most finishes you would use inside won’t survive outside for very long. So with that said, what does work outside?

Finishes, both interior and exterior, come in two basic categories, film finishes and oil finishes. Film finishes build up a protective film on the outer surface of your furniture. These are finishes like urethane, varnish, lacquers, etc. Oil finishes are absorbed into cells of the wood and protect from within.

If you choose a film finish for an outdoor project, I’d recommend a good quality spar varnish, preferably one with UV protection. Spar varnish is different from a “standard” varnish, in that it is designed for exterior use. It is formulated to repel water and the detrimental effects of the sun. It is usually a gloss finish, but with some searching, you could probably find a semi-gloss or satin spar varnish as well. It does need to be maintained, with a new coat every year or two. This may require sanding any rough spots that have developed and a light sanding all over to give the new layers a tooth to hold on to.

Oil finishes work well outside as well, but you don’t get the same feel that you get from a film finish. Oil finishes let you feel the texture of the wood and give you more of a flat finish. Again, make sure you choose a finish that is formulated for exterior use. These are readily available in deck stains and the like. One advantage these have is that they come in several colors and opacity. Another advantage these have is that when it comes time to maintain the finish, you can simply clean off the piece and reapply a new coat.

So what’s the right finish for you? Well like most things in woodworking, it depends. It depends on the look and feel you want; as well as how much maintenance you are willing do in the long run.

Oh yeah, one more thing. The finish you choose is irrelevant if you start with a poor choice of wood, or worse, an old piece that is already starting to rot. That however is a topic for another blog.

Tuesday, August 11, 2009

How is Custom Furniture Priced – Pricing a Bookcase

This is an extension of my last article on pricing custom furniture. In this article I’ll price out a bookcase then change some materials and features. We’ll start with a simple design that is 48” tall, 36” wide and 12” deep. The center shelf will be fixed, and there will be two adjustable shelves.

We will build our first version out of red oak. So what would our book case cost? Based on current material pricing it would sell for $390.00. If we switch to poplar it would lower the price to $360.00. Changing our material to walnut makes the price jump to $505.00. How about an exotic like zebra wood? Well that will run you $750.00, almost double the oak price.

How about we switch from solid wood to cabinet grade plywood (veneer)? There is less preparation, and it can be just as strong, if not stronger, as solid wood. Again starting with red oak we’d be looking at $315.00, a $75.00 savings. A walnut veneer case would sell for $375.00 a savings of $130.00.

With these savings why wouldn’t you always go with veneer? Well, veneers are only 1/128” thick so if you get a scratch it is likely to penetrate the surface. That said, with proper care and a good finish, veneer furniture will last for years and years.

Now let’s take our solid oak bookcase and add a pair of doors to it. We’ll use middle of the road hinges and door pulls. If we go with raised panel doors our price moves from $390.00 to $515.00. Why? More materials and more labor increase the cost. Change the raised panel doors for glass and our new price is $480.00.

So what happens when we change the size? Well let’s go back to our original design and change the width from 36” to 24”. Remember we started with a cost of $390.00 and adjusting the width changes our price to $375.00. Why such a small a change? Because the material difference is minimal, but the labor stays the same. It takes as long to cut a 36” board as it does a 24” board. This is good to know because people often adjust the size in the hopes of getting a better price, when that little or no affect on the cost.

I hope this has given you some insight into what affects the pricing of custom furniture. Materials, design, and features all effect the final cost. I suggest you choose what you really want; you’ll have it for years to come. You don’t want to look back later and say “I wish I had spent a little more and bought what I wanted.