In this two-part series, experienced turner Richard Findley looks into the techniques of turning bowls without a chuck.
Why, and is it possible?
When deciding on topics for this series, I cast my mind back to my own journey through turning. I’ve had many questions directed to me on my travels around the turning clubs of Britain. Something I am often asked by those new to the craft, and indeed something I queried myself is, “Do I need a chuck?” “No, but it makes life a lot easier.” This was the conclusion I came to when I started turning, so a chuck was pretty high on my to buy list. Hence, I have never turned a bowl without one. I know it’s possible to do without a chuck, as the title suggests. I know the theory of how it’s done – I have just never tried. Until now! I have decided to make two bowls using two of the most straightforward methods I can think of. This is using the most basic equipment that everyone will have. I should point out at this stage that this is not another article on how to turn a bowl. I am focusing specifically on the holding methods of working without a chuck.
The chuckless theory
I have chosen to use two methods to explore turning without a chuck. Both will involve using a faceplate – something that almost every lathe has as standard. The first method involves gluing on a sacrificial waste block of timber to allow the use of screws without marking the bowl. The second will rely on jam chucking to enable me to hollow the bowl. In theory, as long as I get my holding points secure and properly formed, turning these bowls should be as simple as turning with a chuck. We shall see!
Preparation
The first job is to select the timber. I choose two pieces of ash (Fraxinus excelsior), without faults or anything that may trip me up along the way. These are in sizes that a new turner would be likely to have: 190mm diameter and 50mm thick. As one piece will need gluing to a sacrificial block, I pass the block over the planer while it is still in board form, and cut the two discs from it.
Glue block bowl method
Gluing the waste block
Some people attach the block using a glue gun, or cyanoacrylate for speed. I use neither in my workshop, so stick with proper wood glue. It quickly becomes apparent that the main drawback of the block method is that you need to plan ahead and glue the block on at least the day before you intend to turn the bowl, to allow the glue to fully cure. Luckily, I remembered the day before my photo shoot. I have picked an off-cut of sapele (Entandrophragma cylindricum), which contrasts well with the ash, and shows clearly in the photos. With the meeting faces of the bowl and the glue block planed flat, I use polyurethane glue and G-cramps to secure the block in the centre of the ash blank.
First stages of turning
With both of my bowls, I use the faceplate to mount the blank to work the base. The faceplate for my old Wadkin lathe is larger than most modern faceplates at 165mm diameter, but it’s what I have, so it is what I’ll use. I check the length of the screws, to make sure they definitely aren’t going to mark the bowl, then drive them home with a driver. With the blank mounted, I round off the waste block and begin to shape the underside of the bowl.
Planning
It quickly becomes apparent that without a little planning, the glue block would encourage an overly large base to the bowl – not something I want. A pet hate of mine is when my equipment tries to dictate to me what I can and can’t make. My plan is for a simple curve to the underside of the bowl, with a little interest added in the rim. To avoid a fat bottom, I try to visualise the curve of the bowl and cut accordingly. This means that I don’t cut the curve simply from the edge of the glue block to the rim, but cut into the bowl somewhat, giving extra ash to work into a foot and allow the curve to continue further round the bowl once the waste block is removed. The final re-turning stage is going to be all the more important for this bowl.
Once happy with the shape of the bowl, I sand by hand to 320 grit. I am acutely aware that when I re-turn the base and remove the waste block, I may need to slightly rework the curve of the bowl. To ensure I can easily remount the bowl to do this, I use the tip of a skew to cut a small but important dimple in the centre of the base.
Hollowing the bowl
The next issue that presents itself: When I remove the faceplate from its initial mount, I need to try to position it perfectly on the waste block to ensure the bowl runs true. Thanks to the little dimple I cut previously, I am able to position the point of my compass in the centre, and draw a circle in the position of the screw holes. Those holes are a little closer to the edge of the block than I would like, but with a small pilot hole to ensure the screw drives in true, this shouldn’t be a problem. When I run the lathe with the bowl now mounted for hollowing, there is a tiny amount of run out.
This doesn’t matter, as I want a wider, more decorative rim. If I had wanted to make a thin walled bowl, this would cause an issue. The only way I can think of avoiding this would be to own two faceplates and mount the second, using the tailstock to help find the exact centre. With the bowl securely held with four 25mm screws into the sacrificial block, I am comfortable taking some quite aggressive cuts and turning the inside of the bowl as I normally would.
Summary
In this first article I have discussed how to fix a bowl onto a lathe using a sacrificial piece of wood. Like with all things, there are pros and cons to this method. Remember that it takes time to fix the item to the block of wood securely. If this proves an inconvenience then you should consider the jam chuck method, which I will discuss in part two of this series. This effectively involves machining a plug and socket that is held together with a tight fit. Read about it in part 2.