13 Ways To Ruin A Woodturned Bowl is a tongue in cheek way of looking at what we really need to do to make a well-turned bowl.
It’s important to know that during the wood bowl turning and learning process, which is never ending, there will be mistakes, and some bowls will turn out less impressive than others.
If you value the positive lessons learned from failure, then here is a list of techniques that will accelerate that failure. 😉
(1) Don’t fuss with the tenon shape
Make any old cylindrical shape for the tenon.
The tenon (or mortise) is the main connecting point and the only way your bowl blank is being held to the lathe.
Take your time and create an angled dovetail tenon that matches the angle of your four jaw chuck.
A tenon shaped as just a cylinder can quickly work free and come loose during turning and send your woodturned bowl flying.
Would you like to see some tenon shapes that can possibly get you in trouble? Check out this article next.
(2) Ignore The Tenon Shoulder
The area at the bottom of the tenon is of little importance.
The shoulder, which works in conjunction with the angled tenon dovetail, must be flat and make firm contact with the top of the four jaw chuck.
If the shoulder does not seat to the top of the jaws, vibration will occur while you turn.
The tenon is used to hold the bowl blank, but the shoulder prevents any side motion when force is applied to the woodturned bowl.
Even a tiny gap at the top of the jaws means the bowl can shift back and forth in the chuck.
Make the shoulder smooth and flat, or you can even make it taper down a bit into the tenon.
If a bowl blank does not sit flush to the chuck jaws, stop, and return the blank to the previous position and correct the shoulder.
(3) Cut in any direction with the bowl gouge
Whatever direction you want to cut on the bowl is fine.
The fiber structure of a side-grain bowl blank (about 90% of bowls are turned side-grain) is like a bundle of straws.
As the woodturned bowl rotates, the gouge is cutting end grain, side grain, end grain, side grain nonstop.
Cutting with a “supported” cut means to cut the top fibers, or “straws” when there are longer straws underneath supporting the downward pressure of the bowl gouge.
Some people call a supported cut “cutting with the grain” or turning “downhill.”
A supported cut leaves a smooth finish because the end grains are not torn thanks to the underlying fibers that support the cut.
When you cut “against the grain,” “uphill” or unsupported, the fibers rip, and the finish is not smooth.
Yes, you can cut in any direction with the bowl gouge, and for roughing out the shape of the bowl, it doesn’t matter as much.
However, if you’re looking for a beautiful smooth finish, and who isn’t, make supported cuts to achieve your desired results.
Be sure to see, Supported Grain Cuts for much more about this topic.
(4) Turn as fast as you can all the time
Lathe speed is designed to go as fast as possible all the time, regardless of the size of your woodturned bowl.
Turning as fast as your lathe will go will produce vibration first of all. But much worse, turning too fast puts you in danger of being seriously hurt.
In general, the larger the diameter of a bowl you turn, the slower you need to make the lathe.
The outer edge of the bowl is traveling the fastest. I know this might seem confusing at first, it did for me.
Let’s take a 15” bowl as an example. If the lathe is set at a speed that makes one rotation in 1/10 of a second, the center of the bowl and the outer edge both make one revolution in 1/10 of a second.
Think about a post in the ground. Imagine putting your hand on top of the post and walking around the post. It might only take five or six steps to complete one turn.
Now imagine being 50 feet from that post and walking a full circle around the post. This much larger distance must be covered in the same exact time that it took you to walk around the post with your hand on top.
Centrifugal forces pull stronger on the outer edges of a bowl and can send pieces of debris or the whole bowl flying if the lathe speed is too high.
This article goes into great detail about determining and controlling lathe speed, check it out.
(5) Take your time roughing a green bowl
Bowl turning should be relaxing. If you’d like to turn the exterior of a bowl today and return next week to clear the interior, that’s perfectly fine.
Turning the outside and inside of a bowl blank at different times, especially if the wood is green or wet, most likely won’t end well.
A piece of wood is under a lot of pressure by different forces, in particular, cellular tension and moisture content.
When you begin turning the exterior of a bowl blank, you are releasing tension bound up inside that tree. Exposing the exterior only still leaves tremendous force at play in the middle of the bowl blank.
If you wait a length of time, the internal pressure combined with the loss of moisture at the exterior bowl surface will crack the end grain.
How long is too long? Well, as always, it depends on many things, but mainly the species of wood, moisture content of the bowl blank, and the relative humidity in the air.
Some people, in dry climates, have to wrap a turning on the lathe with plastic just to take a coffee break. Thinking you can return in several days to core out a bowl, regardless of your particular climate, just isn’t realistic.
If you commit to starting a woodturned bowl, turn both the exterior and interior. This is true if you’re roughing out a twice turned bowl blank or making a finished bowl.
To learn more about various methods to control the drying of wood bowls, see this article.
(6) Ride The Tip
A bowl gouge tip or cutting edge is what does the works, so drive the tip into the bowl blank for the best cuts.
Yes, the cutting edge of the bowl gouge does do the cutting, but to make a smooth, clean cut, you need to “ride the bevel.”
Some people like to call it “floating the bevel.” Riding or floating the bevel, either way is the act of focusing more on the bowl gouge bevel than the cutting edge.
When the bevel is parallel and flush with the cutting surface, the bowl gouge edge will shear away a clean thin layer of material as the bowl gouge precedes.
If the bowl gouge bevel is not flush with the wood surface and the tip of the gouge is leading the pass, there is no support for the cutting edge and the tip skips along aimlessly leaving grooves and ridges instead of a smooth finish.
Learn more about riding the bevel by reading this next.
(7) Ignore a hot bowl gouge
Of course, the bowl gouge is going to get hot, it’s doing a lot of work.
The bowl gouge should work very efficiently and not heat up too much while turning.
If a bowl gouge is heating up, it most likely needs to be sharpened. A dull gouge does more rubbing than cutting, which causes heat forming friction.
Another reason a bowl gouge might heat up is from being overworked. Applying too much pressure can cause the gouge to bite more than it can chew and heat up.
Let the cutting edge do the work and don’t introduce much forward pressure into the cut.
It is possible for very hard wood that is dry to cause a bowl gouge to heat up even when it is sharp, and the cuts are not being forced.
If this is the case, take your time and don’t force the process.
Cool the gouge in water periodically and sharpen frequently.
(8) Forget to heel rub
The heel of the bowl gouge, at the bottom of the bevel, serves no purpose and is not used for anything.
The heel of the bowl gouge plays a significant role in bowl turning.
Especially when you are first learning to turn, the gouge heel is a critical feature to assist in the learning to turn.
When we ignore the heel and simply slide a bowl gouge across the tool rest into a spinning bowl blank, we are bound to get some nasty catches.
We just need to drop the bowl gouge handle a little bit and let the heel touch the spinning surface first to get our orientation right. By lifting the handle and bringing the tip off the heel and onto the bevel, we make a controlled clean entry cut.
The A, B, Cs of woodturning might benefit from adding the heel, making the steps Anchor, Heel, Bevel, Cut. Yes, AHBCs is not as flashy as the ABCs of woodturning, but it will result in a smoother cut.
Also, use the heel to pick up where a cut left off. By dropping the handle and rubbing the heel, we can position the gouge precisely back into a break cutting path.
The act of raising the handle and introducing the cutting tip also lets us easily control the depth of the cut. Starting with only a minor shave at first, the cutting edge engages as the handle comes up.
If catches are a problem for you, here are a few reasons catches occur, and here is an article that details how to avoid catches.
(9) Return To Rim
When you are finishing a woodturned bowl and nearly finished, it’s ok to return to the top rim if you’d like to make a few more passes.
Not So Fast
Once the rim of a bowl has been established, and the majority of the bowl interior has been removed, the rim is no longer stable.
Returning to the rim edge of a nearly complete woodturned bowl will result in an annoying “clack-itty clack” sound.
The inner support of the bowl structure has been removed, and the centrifugal force on the bowl is pushing and pulling at the bowl, causing the sidewalls to flex.
If you make a rim cut, after the bowl center is cleared out, the tool marks will most likely appear on opposite sides of the bowl interior. The bowl gouge will touch one side, and the bowl will pull away, then the opposite side will hit the gouge and so on.
Remember to take your time and form the top rim of the bowl while there is plenty of center mass still remaining in the bowl and do not return to the rim once the bowl is cleared out.
(10) Lock Knees and Push With Hands
Just move the bowl gouge with your arms and hands and stand still while you turn a bowl.
It is our first approach when we start to turn to want to move the bowl gouge with our hands. It makes sense, most “hand tools” require us to manipulate them in all sorts of ways.
The bowl gouge is different than most hand tools.
Our ultimate goal is to make smooth flowing curves on the exterior and interior of our turned bowls.
To achieve these flowing curves, we do NOT want to depend on our hands and arms. Our hands and arms have many joints and are great at making lots of small detailed motions.
We want large sweeping motions, not small short motions. To make broad, sweeping motions, we need to pivot with a larger arch.
The best approach to make sizeable smooth cutting passes is to lock the bowl gouge against your body and make little to no upper body movements. Instead, unlock your knees and shift your body weight from side to side to create the motion.
Position the tool rest in the center of the entire cut you make and position your feet parallel to the tool rest.
Lean slightly to the side to begin the cutting pass. Shift your weight to bring your body to center and continue until you are leaning a bit to the opposite side, all while keeping the gouge firmly against your body.
At no point will you need to reach or feel like you are going to fall over. At first, practice these moves before you turn on the lathe.
After a while, this body shifting “dance” will become second nature and your bowl forms will precisely reflect your motions.
(11) Sand With The Lathe Running
Apply the various grits of sandpaper to your woodturned bowl as it spins on the lathe and you’re done.
Wake Up Call
Sanding with the lathe running only is a recipe for scratch marks in your final wood bowl surface.
Because we turn side-grain oriented wood to make bowls, we have side and end grain throughout each bowl.
When the sandpaper cuts into the spinning side grain, it smooths it nicely. However, when that sandpaper is going perpendicular across the end grain, it rips the end fibers and leaves scratch marks.
Yes, you can run the lathe to sand, but then stop the lathe and sand “with the grain” (the surface grain) to remove the scratch marks.
Then proceed to the next sandpaper grit and so on. Read this article that will show you how to best sand your wood bowls to perfection.
(12) Sign with your favorite pen
Any old pen or pencil you have around is fine to sign your bowls.
Not So Fast
Remember where that woodturned bowl came from? Yes, it was a living tree, and there are a ton of things going on in that wood, many of which we have no clue about.
Inside the wood, even once it’s been turned, there is moisture, tannins, oils, and who knows what other chemical components.
Using an ordinary pen or pencil is not the best way to sign this dynamic material surface. It is not uncommon for pen, and especially pencil signatures to just fade away and disappear.
If you’d like to use a pen, use a high-quality archival permanent ink pen, like this one.
An even better way to sign your name and information to the bottom of your woodturned bowl is with a wood burning pen or iron.
(13) Forget Finishing Instructions
Just smear the finishing product on and then wipe it off or apply however someone else explained.
Finishing products come in an infinite variety. And ideas and opinions on how to use those finishing products exceed infinity.
The funny thing is that the manufacturers of the finishing products want you to get the most out of their product. Why? Because that’s why you bought it and they want you to be a happy customer.
So the manufacturers print these things on the product called “instructions.” Ha! We only need to read and follow them.
I have to tell you, I’ve learned this first-hand with the finishing product that is now my favorite finish.
When I was first introduced to a specific linseed oil-based finish, I was “told” to just wipe it on and let it sit for 5 or 10 minutes and wipe it off.
I did just like I was told, and the finish was good. Good enough that I bought some of the finish for myself.
When I got the finish, I read the can, and the instructions were much different than “wipe on and wipe off.”
The “real” instructions were to wipe on a very thin layer and let it sit for one hour before wiping off any excess. Then let the finish sit for 24 hours and burnish the surface with 0000 steel wool.
Oh. My. Goodness! The surface was fantastic after I followed the manufacturer’s instructions.
What was good before was now great, just from following the real instructions. Imagine.
Woodturned Bowls Ruined
I hope you’ve enjoyed this tongue in cheek, somewhat backward way of pointing out some of the more critical aspects of making woodturned bowls.
Although some of the examples are funny, all of these points are very real, and I see or hear about people doing them all the time.
Turning wood bowls requires the understanding of numerous skills and techniques.
If you are new, realize it will take time to build up this knowledge base. If you are experienced, appreciate where you are and know that there is always something new to learn.
So, how have you ruined a wood bowl? We’ve all done it, usually in numerous ways. Share a comment below.