Weekend projects - Simple salad bowl archive

Friday 18 September 2015

Mike Mahoney starts off his new series of turning things for the home by showing you how to make a simple salad bowl from an ash bowl blank

Gallery

I picked the salad bowl for my first article in my new 'make it & use it' series because I believe every household should have one. Besides, most of us woodturners have given bowls a try at some point or another. There are many factors to consider when attempting to make a bowl for your kitchen. The first thing is the size - what is appropriate for your needs? A typical bowl size is 255 x 90mm. It will hold just about anything we want to put into it. If you need to make your bowl larger, however, I would think about adding 25mm in diameter for every person in your home. The height of the bowl will have to be proportioned as well. To understand proportion better, I follow this equation: whatever the diameter of the piece, the height should be one-third of that number. For instance, a 305mm diameter bowl should be 10mm tall. Likewise, a 610mm bowl should be 200mm high. Plus or minus a bit is not that big of a deal. However, don't underestimate how proportion affects your bowl's beauty and function. Bowls that are too deep in comparison to their diameters are hard to use. Bowls that are too shallow look wanting. Along with proportion, base diameter is also an important consideration. For a functional piece, I would never make the base diameter smaller than one-third of the rim diameter. Having too small a base will make your piece unstable which will limit its use. Too large of a base may hinder its beauty. My 255mm bowl has a 90mm base. This bowl can be completed in around two hours.

Tools used:

10mm bowl gouge

12mm shear scraping gouge

12mm spindle gouge

12mm traditional gouge

16mm bowl gouge

A note on drying

Air drying bowls is different for every woodturner due to a number of factors, including the area we live in, where we store them, wood species, and moisture content of the wood. Since I live in an arid desert climate, I wax the entire piece. If you live in a more humid climate, you may just do the end grain or not apply a sealer at all. Drying times will also vary significantly depending on the above factors. This ash (Fraxinus excelsior) bowl will dry in 90 days in my drying room and will then be ready for turning.

A note about design

Most bowls have the same shape. What you do between the base and the rim is how you will create a theme or personality to your work. The sky is the limit. For me a well-designed bowl will have a detail somewhere between the top or bottom one-third of the piece. The detail's scale should be proportionate to the object you are making.

STEP 1

Start the project by taking a piece of ash which has a 305mm diameter

STEP 2

Next, split the log through the pith using a chainsaw. You can then round the blank with a bandsaw

STEP 3

Drill a hole to accept the screw centre or a screw chuck; this will attach firmly against your chuck and you can then apply the tailstock

STEP 4

Firstly, remove wood on the largest diameters of the bowl blank working parallel to the bed of the lathe using a 16mm bowl gouge

STEP 5

After it has been trued up you can start to shape the sides of the bowl. These are a quick series of cuts to get to the rough shape of your future bowl

STEP 6

Now form a tenon that will be nearly half the size of the bowl's diameter. I recommend that all woodturners doing any sizable turning consider having a large chuck that can grip large diameters; a must-have tool for safety. The tenon in this case is 125mm with a 6mm gripping area

STEP 7

Once you have formed the exterior in its rough shape and the tenon, remove it from the screw and attach it to your chuck. Notice there is no gap between the face of the chuck and the wood. This is a crucial point to make. If the tenon is improperly formed then it will have an opportunity to fail, potentially leading to disaster

STEP 8

Now true up the face of the blank with a 16mm bowl gouge, then start to remove the interior. This particular bowl will be 25mm thick when completely roughed out

STEP 9

Before you apply a green wood sealer, roll the corners of the rim of the bowl. This helps in the drying process. Sharp corners create stress points that can facilitate a crack

STEP 10

Once this is accomplished, apply the green wood sealer...

STEP 11

... making sure that all of the surface is coated. Store in a cool place

STEP 12

After the bowl is dry, put it back on the lathe and re-turn the tenon. Support it up against the chuck and also bring up the tailstock for support

STEP 13

Once the tenon is clean and true, put it in the jaws of your chuck. Next, true up the rim. I have found it best to establish the rim first before designing the exterior

STEP 14

Now true up the exterior with a pushing cut, working with the grain, then take a series of shear scraping cuts with the 16mm bowl gouge

STEP 15

Once you have the desired shape, change to a 12mm gouge that is made from a softer tool steel and is swept back severely. This helps put a steeper shear angle on the wood for a smoother surface. The softer tool steel gives a keener edge

STEP 16

Once you have the design finished on the exterior, detail the rim. I like to have a very thick rim that has a slight ogee curve sloping inwards. Use a 10mm bowl gouge with a short bevel to accomplish this

STEP 17

Then undercut the rim using the same gouge. I cut two-thirds of the way down the bowl always working top to bottom. The under cut of the rim facilitates gripping. Check to make sure the surface has been cut cleanly since this is a mostly end grain cut. It requires the sharpest edge you can get. If a sharp tool and good technique is still giving you torn grain then you can lubricate the cut with a bit of the finish that you will later apply to the finished piece. This usually will solve the problem

STEP 18

Next, use a 12mm bowl gouge with a traditional grind to finish the bottom one-third of the bowl. The traditional grind, in my opinion, will give a better surface than any other designed gouge; this is because of its unswept wings, which cuts the wood with a steeper angle than a fingernail design in this situation

STEP 19

When you have a smooth curve on the interior you can use either a hand or power sanding technique to refine the surface of the entire piece - I power sand with a 75mm disc sander

STEP 20

Remove any blemishes with the lathe turned off. Be careful to keep the sander moving so you do not create any flat spots. Once all the blemishes are removed sand from 120 to 320 grit with the bowl spinning in forward and, if you have it, reverse. I finish off with a hand-held 400 grit paper sanding in forward and reverse. Once sanded, spray a light mist of water over the entire piece. This raises the grain. After a minute or two of drying sand with the same old 400 grit paper to cut the raised grain, again in forward and reverse. Apply enough pressure to get a bit of shine on the wood. By using this process you will remove the ability of the wood to become furry when it gets wet with use

STEP 21

Now remove the bowl from the chuck and remove the tenon marks using a vacuum chuck, or similar method

STEP 22

Use a series of shear scrapers to blend the tenon with the sides

STEP 23

Now detail and finalise the base and sand with the same process as before. And to finish, sign and date the piece, then apply the finish. I used a heat-treated walnut oil for this bowl. The finished article should look something like this


Woodworkers Institute

Tagged In:

Mike Mahoney , Weekend Projects


Handy Hints

1. The screw centre is the most convenient way to mount a bowl blank of this size. Make sure the face of the bowl blank screws firmly to the face of the chuck otherwise you will bend the screw. Other options are two or four-prong drive spurs. This will allow you to balance the bowl's grain if you do not cut it out of the log correctly
2. Inspect your roughed out bowl carefully. Make sure all cracks radiating from the pith have been removed
3. When making a cut on the interior rim the gouge has a tendency to skate across the rim of the bowl. To solve this, bring the gouge to a horizontal position and make contact with the top or point of the gouge. Therefore there is nowhere for the gouge to skate. The skating is caused by the force of the spinning bowl making contact with the gouge below the top of the gouge. The spinning bowl hits the gouge and drags it to its end point - the top of the bowl
4. If you are giving the salad bowl as a present then provide the recipient with some care instructions. Proper care should ensure a long life to your project. Here is a sample of what I put on a postcard that I give out for every bowl I make: "After use, simply hand wash with normal dish soap then let air dry. Occasionally recondition the bowl with mineral or walnut oil. With proper care this bowl will last for generations"
5. Before you spin the bowl to power sand, remove any torn grain or blemishes with the lathe turned off. Make sure you are constantly moving your disc so you don’t create any flat spots. Use air compression to clean the wood grits

Diagrams Click an image to enlarge