September 24, 2023

wall papers

Your Dream House

Wood Bowl Exterior-Critical Design Moment

Wood Bowl Exterior-Critical Design Moment

The wood bowl exterior is the moment woodturning mechanics meet artistry. Many of the steps in creating a wood bowl are just that, steps. However, the wood bowl exterior is a different animal.

Wood Bowl Exterior-Critical Design Moment

There is a critical design moment when we arrive at the wood bowl exterior stage of the turning process. Here we need to step away from routine and visualize the possibilities.

The wood bowl exterior is the wood bowl. What do I mean? Think about it, the entire look of a wood bowl is conceived by and radiates from the exterior design.

Everything leading up to the formation of the bowl exterior are mechanical steps mainly to best secure and prepare the bowl blank. And almost every turning step after the wood bowl exterior creation is dictated by that established exterior shape.

Wood Bowl Exterior Lead Up

Before arriving at the wood bowl exterior, several steps play out. We find the ideal bowl blank and determine an appropriate way to attach the bowl blank to the lathe first.

With the blank attached to the lathe, we clean up and level the bottom and side surfaces and decide whether to use a tenon or mortise to hold the bowl bottom to the lathe, when that time comes.

Once the tenon or mortise debate has been decided, we measure our four jaw chuck and transfer that measurement to the bowl blank. Then we form an ideal tenon or create a recessed mortise to securely fit the wood chuck.

All the steps, up to this moment, brings us to the wood bowl exterior. No longer are there measurements or mechanical steps to execute. Instead, we need to be creative and visualize the possibilities for our wood bowl exterior.

Start At The Bottom

When I reach this moment of the wood bowl exterior, I like to establish a couple of parameters. These parameters will help form a framework for the final bowl shape.

The first parameter is the bowl foot. What type of foot will this bowl have? At this moment I start asking myself questions like: “What size should the foot be? How tall do I want the foot? Will it be a thin rimmed foot or perhaps a convex curve?”

All of these questions and possible bowl foot options need to be considered first. Why first? Because the wood bowl exterior has a start and an ending location, one of which is the bowl foot.

Wood Bowl Exterior Foot Options

Another option to consider is using the tenon area to continue later shaping the final bowl foot. While the tenon should be kept substantial to hold the bowl while turning the interior later appropriately, it can be reduced at the end of the turning process.

Wood Bowl Exterior Foot Included in Tenon Options
Wood Bowl Exterior Foot Included in Tenon Options

Once the foot size, shape, design, has been determined and created, a critical puzzle piece of the wood bowl exterior is put into place.

The bowl foot plays a vitally important role in the overall look and feel of the finished bowl more than almost any other component. Because of the bowl’s foot importance, it must come first in the design process.

Wood Bowl Exterior Rim

Once the bowl foot has been turned and shaped, the next parameter to nail down is the wood bowl rim. How do you what the wood bowl exterior rim to appear?

Here are a few questions I like to consider at this point. Will the rim be flush ninety-degrees? What if the rim angles inward or outward? Do I want to make any decorative details around the rim?

Because we have the entire bowl blank to work with at this stage in the turning process, we can do almost anything we want with the bowl’s rim design. If we begin turning and shaping without a plan, the bowl blank options may become more limited.

Something to consider, especially if there are any defects along the wood bowl exterior rim, is making an inward curved asymmetrical rim design. The inward rim shape will remove any undesired blemishes or cracks along the top edge of the wood bowl blank and make a very attractive bowl design.

Wood Bowl Exterior Rim Design Options

Connecting The Dots

With the bowl foot and rim design determined, we’ve removed much of the ambiguity of the wood bowl exterior design process. We have established a platform for our bowl design far beyond a daunting blank canvas.

The bowl foot and rim design now anchor the wood bowl exterior design and give us a start and end point. We only need to connect the dots.

Now we can much easier visualize the final bowl shape with a beginning, and an ending location establish. This visualization process is critical because we must see the final bowl shape, in our mind’s eye, first before we turn any wood.

Step back from the lathe a bit, if necessary, and closely look at the cylinder of timber. See the foot that you’ve already shaped and imagine the rim you have decided. See those two elements and then see the shape of the line connecting them.

The goal is to turn a clean, graceful line, regardless of the line’s shape, from the point of the foot to the rim. Ideally, the wood bowl exterior shape will blend seamlessly with the foot and rim.

Visual Aid

If you’ve decided to refine the tenon later further to form the final bowl foot, you may want to create a little visual aid. It can be difficult to see the overall bowl shape with an oversized tenon base in the way.

When I know I will be removing excess tenon material to make a more elegant and petite foot; I need a visual aid to guide my creative vision. The tenon needs to stay relatively large for support, but I have a little secret.

Instead of potentially being misguided by looking at the bulky curve of the required supportive tenon, I will make a detour. Using my bowl gouge, I will back cut the starting point of the final foot design.

Keep in mind, I don’t want to diminish or reduce the required supporting tenon too much. However, I do want to establish a visual line that will help my eye see the shape that will later lead to the final foot.

With this indentation created, it is much easier to visualize the curve leading to the foot and connect it freely up to the bowl’s rim shape.

Wood Bowl Exterior Tenon Included in Foot Options

Wood Bowl Exterior Options

We only need to connect the dots to make the final wood bowl exterior shape. So what will that shape be? Of course that decision is up to you.

Personally, I prefer simple bowl shapes. Simple curves seem to make the most elegant finished bowls. Those simple shapes can be quite deceiving to execute. However, with the foot and rim nailed down, they are much easier to turn.

The options for the final wood bowl exterior are somewhat limited by the amount of wood available in the bowl blank. A wide flat bowl blank may have fewer or different options than a taller narrower blank.

Start With The Basics

Nothing is more basic than a straight line. What if you connect your bowl’s foot to the rim with a straight line? Will it work for your wood bowl exterior design?

A straight line is probably the easiest option available and the quickest to visualize while staring at the bowl blank on the lathe. Perhaps this can work for the bowl design at hand.

Wood Bowl Exterior Straight Edge Connecting Foot to Rim

Simple, elegant curves are beautiful. We all love them. Consider how a curve may appear connecting the foot to the rim.

An easy way to visualize a connecting curve is to use, or imagine, a chain linked from the bowl foot to the rim. Hold up the chain and imagine one end being the bowl foot and the other being the rim, watch the arc between these points as gravity takes effect. See the curve change as you rotate the points.

Wood Bowl Exterior Natural Curves With Chain

Visualizing a curve to the bowl blank cylinder can be a little bit more complicated than seeing a straight line. However, by removing smaller areas from the bowl blank at a time the final curve will gradually take shape. Take your time and remember to visualize the curve as you turn.

Kick It Up A Notch

If you want to add a little bit of a challenge to your wood bowl exterior, try making an ogee shape. Did he just say “oh gee?” you might be thinking. Yes, ogee.

An ogee is an “s” curve or two curves that go opposite direction but connect in the middle. The term ogee is a mathematical term that denotes an inflection point. Ogees have been used in architecture and all sorts of applications for thousands of years.

Wood Bowl Exterior Ogee Graph Example

We can apply an ogee shape to our wood bowl exterior by starting an outward or convex curve up from the foot that shifts to an inward or concave curve before reaching the rim.

The ogee curve is a bit more complicate to execute but does add a whole new level of interest in the bowl design. The ogee also sets up for a very pleasing and graceful bowl interior where the rim can gradually drops down into an spherical pool.

Interested in turning an ogee shaped bowl, then check out this article next all about making an ogee bowl.

Wood Bowl Exterior Ogee Shapes

Wood Bowl Exterior Execution

Whether you decide to go simple, complex or something completely different of your own choosing, the execution of the bowl exterior is the cornerstone of the entire bowl design.

With a design established and a plan in place, all that remains is to turn the shape. I like to quickly remove waste material with my large bowl gouge, and I save my smaller bowl gouge for the final cuts that really need to be precise and clean.

As I turn away waste material, I am continuously visualizing the shape that is forming on the bowl blank and matching that to what I’ve planned and visualized. Occasionally I’ll leave the lathe running and step back a bit to see the overall shape clearer.

I typically start my final exterior cuts at the foot of the bowl and work my way to the rim. Because I usually turn side-grain bowl blanks, I will use supported grain cuts from the foot towards the rim.

If I’ve chosen a rim design that is curved inward, I need to remember to reverse my cut direction along the rim. In those instances, the rim will need to be turned from the rim towards the outside of the bowl exterior to perform a grain supported cut.

Wood Bowl Exterior Inward Rim Supported Cut Directions
Wood Bowl Exterior Inward Rim Supported Cut Directions

At this point, the bowl shape is nearly complete, and the shape is tangible and present. With my smaller bowl gouge freshly sharpened, I make the final passes across the wood bowl exterior.

When I’m turning these final cuts and all the turning cuts for that matter, I always try to ride the bevel of the bowl gouge. Riding the bevel is the best way to assure clean, efficient cuts that leave a fine surface.

As I turn and shape the bowl, I’m watching the top profile edge of the bowl as it takes shape. There and only there will I truly get a sense of the final bowl shape as I turn.

Wood Bowl Exterior Look at Top Bowl Form

When I’m almost done turning the bowl exterior, I will look for any blemishes, bumps, or tool marks. This is a great time to use the bowl gouge scrapping technique to level any high spots. I will then use the more refined shear scraping technique to smooth and finish the bowl surface.

Wood Bowl Exterior Design Ideas

Conclusion

“The wood bowl exterior is the wood bowl!” When you next approach the lathe to turn a bowl think about that phrase.

Because the wood bowl exterior is so essential, it is the one time along the whole turning process when we need to slow down and put a bit more purpose and thought into our actions.

The character, look and feel of a beautiful wood bowl all pivots on the execution and design of the bowl’s exterior. When we shape the exterior is the moment we get to shine as the creator of each bowl.

Decisions are made on the bowl’s exterior that controls how that bowl is seen, felt, held, appreciated, admired, and critiqued. Isn’t it worth taking a little more time while making the wood bowl exterior? I think it is.

Please share with me your thoughts below. How much do you consider the importance of the exterior of the bowls you turn?


A book that I’ve gained much knowledge from is The Art of Turned Bowls: Designing Spectacular Bowls with a World-Class Turner by Richard Raffan. It’s worth checking out and having on hand as a great resource. Richard is a pro production turner and he has a wealth of knowledge to share on the subject of bowl design.


Check out these other articles to learn more about bowl design:
• OGEE BOWL DESIGN – HOW TO (UNDERSTAND, DESIGN, MAKE)
• 7 WOOD BOWL WOODTURNING BOOKS – FAVORITES
• SPALTING AND SPALTED WOOD BOWLS
• BOWL TURNING GRAIN ORIENTATION – WOOD BLANK DIRECTION


As Always, Happy Turning,
Kent

Source Article