The bowl turning grain orientation of a bowl blank can seem like a confusing puzzle when we first begin bowl turning.
What is the bowl turning grain orientation of the wood used to turn a wooden bowl?
The bowl turning grain orientation for most wood bowls is a side-grain orientation. However, end-grain bowls, less common than side-grain bowls, can be turned from a raw log as well.
Let’s dive deeper into the details.
It is very common for people to think that all wood bowls are made from a round log oriented in the same vertical direction in which the tree grows.
While making bowls like this is an option, it is not as popular or as versatile as a side-grain oriented bowl blank.
Side-Grain and End-Grain Bowl Blanks
For clarity, let’s take a look at a side-grain and an end-grain bowl blank before we go any further.
A side-grain bowl blank has end-grain fibers, or the ends of the cellular wood fibers are visible on two sides of the blank.
On the opposite sides and the top and bottom of a side-grain bowl blank are horizontal running side-grain parallel wood fibers.
End-grain bowl blanks have end-grain fibers on the top and bottom of the bowl blank and parallel vertical running wood fibers on all four sides of the blank.
The Pith Is The Pits
The pith, or center core of the tree, is usually subject to the most tension and pressure as a piece of wood dries.
Because of this tension, the pith and area surrounding the pith typically crack and split apart.
When you first start turning, it’s a great idea to cut away the pith area from your bowl blanks to avoid that discouraging pith split.
However, as you turn more and learn which timber has pith that doesn’t crack horribly, you may choose to leave the pith in your turnings.
Some people enjoy leaving the pith, cracks and all, in there work and it can be beautiful.
But if you’re looking for a beautiful clean bowl, you may want to cut away the pith area and avoid the pith headaches.
The pith is another reason end-grain bowl blanks are not the best to turn because they usually contain the pith right in the dead center of the bowl bottom.
Strength From Side-Grain
Side-grain bowls not only have more strength than end-grain bowls, but they also offer more diversity in terms of dynamic wood grain appearance.
Because side-grain bowls are positioned sideways to the grain flow of the tree, they have two sides of parallel flowing grain and two sides of end-grain.
If we think of the grain pattern of a side-grain bowl, it is a lot like a bundle of drinking straws bound together.
This bundled effect gives a side-grain bowl strength and structure that makes it a good option when designing and creating beautiful bowls.
One downside of side-grain bowl turning is the continually changing surfaces from side-grain to end-grain fibers that need to be cut cleanly with each rotation of the lathe.
A common issue is that the end-grain fibers can easily get broken or torn off, instead of cutting cleanly, causing end-grain tear out. In comparison, side-grain fibers usually cut cleanly with little trouble.
Some species of wood are prone to end-grain tear out more than others. Usually older, dry wood will tear out on the end-grain more than fresh green wood.
This effect of end-grain tear-out can be avoided by taking extra precautions and care when turning. Here’s an article all about avoiding end-grain tear out.
End-grain bowls are less common than side-grain, but a bowl can be made using end-grain directed wood fibers.
Primarily, the wood fibers run from top to the base of an end-grain bowl.
Making clean grain supported cuts with end-grain bowls requires that the bowl gouge is used in opposite cutting directions compared to side-grain bowls.
Understanding support grain cuts when turning is critical. Here’s an article that thoroughly covers this topic.
While the bowl turning grain orientation of an end-grain bowl is not common, it can work well for ornate more artistic turnings.
End-grain turning also works well for hollow forms and deeper bowls that start to be more vase or vessel-like compared to a traditional bowl shape.
Because the end-grain bowl has vertical running wood fibers, the exterior appearance and wood patterns will be different than side-grain bowls.
Attaching an end-grain bowl to the lathe works excellent with a tenon because the tenon is compressing wood fibers. However, don’t use a mortise with an end-grain bowl.
A mortise attachment point will expand, push apart and break the wood fibers on an end-grain bowl and potentially fly off the lathe.
The inside bottom of an end-grain bowl is made up of one-hundred percent end-grain.
If an end-grain bowl is made with a porous wood, the bottom of the finished bowl can be mostly perforated, and act more like a sieve than a bowl.
Also, if the end-grain bowl blank contains the pith of the tree, there is a good chance of having cracks or splitting in the bowl bottom.
These are all reasons why most wood bowls are turned used side-grain oriented wood, also minus the pith.
Simple Bowl Blank Locating
The simplest way to approach bowl turning grain orientation is to take a medium round log and split it in half lengthwise through the pith.
After a log is split, there are two half-circle halves that can be used to make two bowls.
The most straightforward approach is to use the flat side of the split log as the top rim side of the bowl.
It is usually best to remove the excess corners by rounding the bowl blank on a bandsaw. You can also trim off the excess wood in the field using the chainsaw.
Small And Whole
If you come across smaller logs, approximately four to six inches in diameter, you can turn an entire cross-section into a wood bowl.
Many times I’ve come across downed limbs and cut off a small cross-section and used that to form a bowl.
I simply mount the whole piece, sideways or side-grain to a screw chuck or spur bit drive center, and form a small tenon on the tailstock side before flipping and forming the bowl.
This technique utilizes the entire piece of wood and usually contains the pith.
Again, depending on the type of wood, the pith area will react differently.
I have done this with oak and watched the pith area slowly blow apart the whole bowl.
I’ve also made this type of small bowl with elm, and the pith moved but it didn’t even crack a tiny bit.
Seeing the pith structure and surrounding grain patterns makes this little bowl look amazing!
You will need to experiment and see what works best for you.
Natural Edge Blank Orientation
Using the same split log from the example above, you can make a natural edge bowl.
Instead of orienting the top rim to the flat side of the log, make the curved bark edge the top of the bowl.
I like to make a level flat spot in the bark side of the blank large enough to accept a faceplate.
This flat spot can be made with a hammer and chisel or a small grinding wheel. Here is the grinder and cutting wheel I use.
With the natural edge blank attached to the lathe, I then use the flat side of the log to form a tenon and shape the bottom of the natural edge bowl.
Another thing to keep in mind with a natural edge bowl blank is the blank can be shaped longer on the initial log than a regular bowl.
The extending wings of a natural edge bowl do not need to be confined within a perfect cylinder as a regular bowl does.
I cover this detail along with nine other tips in my Live Edge Bowl – 10 Secrets For Turning Success article, here’s a link to take a look.
Regular and Natural Edge Bowl Grain Orientation
Because the natural edge bowl is turned in the reverse direction of the regular bowl, the wood grain pattern is also reversed.
As this illustration details, the location of the pith and the extending grain arcs is located at the top of a regular bowl, but at the bottom of a natural edge bowl.
Because the pith and subsequent grains are positioned opposite in each of these bowls, the bowl grain appearance is also different.
Having the pith at the base of the bowl, with the natural edge bowl, creates a small oval in the bottom of the bowl with progressively larger grain ovals coming up the sides of the bowl.
With the pith located near the top rim on a regular bowl, grain patterns can look more like a letter X as they proceed through the bowl sides.
Balanced Wood Grain Orientation
For a while, when I first started turning, I would wonder why some of my bowls had grain patterns that crept up one of the sides of the bowl and weren’t centered.
The answer is in the pith.
In order to have a beautiful, centered grain pattern, the pith area needs to be centered or balanced in the bowl blank.
I was simply cutting logs in half based on where they were laying on the ground.
The pith was the target point at the center of each log, but I wasn’t bothering to visualize and balance the wood on each side of the pith.
How To Balance Your Blanks
Instead, of merely cutting a log in half through the pith, first, look where there is an even amount of wood on each side of the pith.
If the pith is perfectly centered in the log, then cut away. But we all know that rarely is the pith perfectly centered.
Draw a line through the pith that is equal in length on both sides of the pith.
That is where you want to cut to achieve balanced grain lines within a final wood bowl.
Making this balanced cut will sometimes leave you with odd-sized pieces to turn. In most situations, that will usually be better than turning with an off-centered pith location and out-of-balance grain patterns.
Orienting Wood Grain In Large Bowl Blanks
The luxury of obtaining large logs to turn can allow you to be more creative in your bowl blank creation process.
Large Log Negatives
Ok, learn from my mistakes.
When I had my first opportunity at getting my hands on some BIG logs, I was thrilled.
With my chainsaw roaring, I split log after log right down the middle and made two HUGE half-circles.
While this approach of just splitting a large log and dreaming of making the world’s largest bowl can work, there are a few drawbacks.
First of all, the blanks are massive and very difficult to work with, and exhausting to turn.
Secondly, the more massive logs have more extensive pith areas, and those areas are still present in the remaining split logs.
The width of the chainsaw cut does not remove the entire pith tension area. The pith cracking area on some large logs can be several inches wide.
The flat faces of the logs still split on me due to pith inclusion, and I had to waste all that surface area away on the lathe.
Large Log Upside
Now, instead of thinking of large logs just like small or medium logs, I approach large logs more like a butcher.
How and where can I get the most valuable cuts?
Using a lumber crayon (here’s a link to the ones I use), I mark off the entire pith area and work from there.
Usually, I will designate a quarter-sawn area above and below the pith waste area.
If you have a very linear wood grain pattern, don’t overlook the quarter-sawn areas. Check out this article for some quarter-sawn inspiration.
Working outward, I will mark the thickness of the first slabs until I’m left with the outer curved blanks.
Using this technique gives me the best use of the large log and provides many turning options.
The inside flat slabs can be oriented to the lathe on either side depending on which way you’d like the wood grain to appear on the final bowl.
Bowl Blanks From Crotch Wood
Tree crotches are the bane of mills, tree trimmers, and even firewood splitters.
If you can’t locate tree crotches for yourself, ask around, and any of these sources will usually be happy to get rid of their wood crotches.
A tree crotch can be turned in numerous ways.
For making bowls, I prefer to split the crotch in half through the pith area, leaving two Y shaped pieces, with flat bottoms made from the cut.
The wood crotch can be the origin of some of the most amazing natural edge bowls, but there is definitely an element of luck involved as well.
Tension and merging growth patterns in a crotch, called flame, can be quite striking. But getting the flame where you want it depends where the final bowl bottom is located.
After a few natural edge crotch bowls, you will get a sense of where the flame might appear and begin to position the bowl bottom to best display the flame.
I start by using the same technique of leveling a top bark-covered area with my angle grinder to form a flat mounting surface for the faceplate.
The flat side of the crotch is used to form a tenon and then curved to form the bowl bottom before flipping the bowl for finishing.
Quarter Sawn Bowl Blanks
I came across this amazing quarter-sawn wood grain pattern when I was working a large Honey Locust tree.
The grain of the Honey Locust is very uniform, linear and makes incredible quarter-sawn patterns.
Quarter-sawn wood is wood that is cut perpendicular to the grain lines.
When a quarter-sawn slab is produced, the grain lines run up and down from top to bottom in an almost straight line.
Larger logs usually produce the most even and straight quarter-sawn blanks.
The effect of these vertical grain lines can be very graphic and
linear in nature and provide for dramatic-looking bowls.
Don’t let the lines fool you. A quarter-sawn bowl blank is still usually turned in a side-grain orientation.
Remember where the end-grain open wood fibers are located to determine if a blank is side or end-grain oriented.
Are you interested in making a quarter-sawn wood bowl? Read this article next.
Bowl Turning Grain Orientation Conclusion
Perhaps, as you read this, you’re picking up an overall idea about bowl turning grain orientation.
Yes! You can pretty much orient a piece of wood any way you’d like when making a wood bowl.
I’ve covered most of the basics here and some of the more advanced ways to orient wood grain in your bowls.
Later with experience, you could, for example, orient a piece of wood at a forty-five-degree angle and form a bowl. The process would be challenging, but it is possible.
Whether it’s a regular rim bowl, natural edge bowl, crotch bowl, quarter-sawn bowl, or an end-grain bowl, you can make whatever you want.
While you can orient wood almost any way you’d like, the bowl blank orientation will affect the final bowl’s overall wood grain appearance and performance in one way or another.
If you’re starting, I suggest keeping it simple. Make a few regular rimmed bowls, then experiment with a natural edge bowl.
Compare the grain patterns of the two bowls and begin to appreciate subtle differences in wood grain appearance.
By understanding how you can orient a piece of wood the way you desire, you will then have more control over the final look and appearance of every bowl you make.
You’re gonna want to read these too:
• SUPPORTED CUT WOOD GRAIN – BOWL GOUGE CUT DIRECTION
• TWICE TURNING WOOD BOWLS – HOW TO STEP BY STEP
• TURNING GREEN WOOD BOWLS – THE PROCESS
As Always, Happy Turning,