Dr.Al
Old Oak
After all the experimentation with the duplicator, I wanted to get back to more conventional turning for a little bit longer before I hang the lathe from the ceiling again.
I recently bought a couple of big bowl blanks. One of them is destined to be a new fruit bowl and is big, both in diameter and thickness. Turning a bowl of that diameter is going to be a bit challenging, so I thought I'd try with the slightly thinner one first (for which I have no particular target in mind).
It started off looking like this:
If you're eyesight is good enough, you'll have figured out it's Brown Oak and 280 mm diameter, 50 mm thick. If you look closely at the left-hand edge, you'll see the wax has been removed a bit - that's where I clearly didn't get the face plate quite central and had to hand plane a little off to get it to rotate without hitting the bed. The theoretical maximum diameter for my lathe is 281.4 mm, but I think we can realistically call it 280 mm max.
Turning the outside shape was quite straightforward and, with all the practice I had last year, I didn't have too much problem turning the inside either. With that all done, it looked like this:
So far, so straightforward. However, in order to maximise the thickness of the part, I'd hot-melt glued a bit of Sweet Chestnut on the bottom and that's what was held in the chuck:
That needed to be removed and there was zero chance that I'd get this in the Cole Jaws so a different approach had to be used. I did wonder about just soaking it in Isopropyl Alcohol (which will defeat a hot melt joint), but getting enough into the right places struck me as next to impossible without removing most of the Sweet Chestnut anyway, so I decided to remove as much as possible on the lathe.
In November I went along to a meeting of Gloucestershire Association of Woodturners and the demonstrator there handed out some cubes of foam. The foam came from the company for which he worked and is typically used for insulating sea kayaks if memory serves me correctly. After cutting it to size to fit the kayaks they have a lot of off-cuts and he'd brought along a box full for anyone who wanted a block to take away.
I cut the block in half and used Gorilla Glue to stick it to a bit of oak. Once the glue had been left to set, I skimmed the outside round, leaving a slightly rough finish, but it's foam, so that doesn't really matter.
One of the rarely but occasionally handy accessories I've got for my lathe is a live centre with an M33 thread on the end. When I'd removed the bowl from the lathe after doing most of the turning, I'd left it in the chuck and just removed the whole lot. I mounted the chuck on the M33 live centre and put that in the tailstock. I could then push the tailstock up against the foam block, compressing it rather a lot:
The foam block provides the transfer of the motive force, the chuck in the live centre keeps everything concentric, at least until I cut all the way through the Sweet Chestnut block at which point I would expect the bowl to go flying across the workshop!
I took it quite gently, stopping every now and again to see what it was looking like:
I'd mostly finished the bottom surface before gluing the Sweet Chestnut on, so in an ideal world I'd just remove the Chestnut and glue and leave an immaculate surface, but I'm not that good at turning! Has anyone on here ever tried turning a bowl with a sacrificial base held on with a couple of layers of masking tape and some superglue? It'd be quite easy to get off of course, but I'm a bit nervous about whether it'd hold well enough for hollowing out the inside of the bowl.
A bit more progress - you can see that a downside of this holding method (rather than just using a live centre into a centre dot) is that the chuck stops the rest from getting close, although it didn't seem to be too much of an issue:
This is the point that I decided to stop:
I took it off the lathe and used a Dozuki to saw off most of the sacrificial block, leaving this much:
Most of that got removed with the 80 grit sanding disc on the lathe spindle (visible in the background of the photo). The last bit got removed with a random orbital sander, using a bit of plywood as a temporary work surface:
I've found my Mike's Magic Mix now so I used that for the finish. It's had one coat so far:
Side view:
I found the process of turning away the sacrificial piece without the Cole Jaws a bit daunting but it worked quite well all things considered. Perhaps next weekend I'll psyche myself up to turning the big Ash blank into a fruit bowl.
I recently bought a couple of big bowl blanks. One of them is destined to be a new fruit bowl and is big, both in diameter and thickness. Turning a bowl of that diameter is going to be a bit challenging, so I thought I'd try with the slightly thinner one first (for which I have no particular target in mind).
It started off looking like this:
If you're eyesight is good enough, you'll have figured out it's Brown Oak and 280 mm diameter, 50 mm thick. If you look closely at the left-hand edge, you'll see the wax has been removed a bit - that's where I clearly didn't get the face plate quite central and had to hand plane a little off to get it to rotate without hitting the bed. The theoretical maximum diameter for my lathe is 281.4 mm, but I think we can realistically call it 280 mm max.
Turning the outside shape was quite straightforward and, with all the practice I had last year, I didn't have too much problem turning the inside either. With that all done, it looked like this:
So far, so straightforward. However, in order to maximise the thickness of the part, I'd hot-melt glued a bit of Sweet Chestnut on the bottom and that's what was held in the chuck:
That needed to be removed and there was zero chance that I'd get this in the Cole Jaws so a different approach had to be used. I did wonder about just soaking it in Isopropyl Alcohol (which will defeat a hot melt joint), but getting enough into the right places struck me as next to impossible without removing most of the Sweet Chestnut anyway, so I decided to remove as much as possible on the lathe.
In November I went along to a meeting of Gloucestershire Association of Woodturners and the demonstrator there handed out some cubes of foam. The foam came from the company for which he worked and is typically used for insulating sea kayaks if memory serves me correctly. After cutting it to size to fit the kayaks they have a lot of off-cuts and he'd brought along a box full for anyone who wanted a block to take away.
I cut the block in half and used Gorilla Glue to stick it to a bit of oak. Once the glue had been left to set, I skimmed the outside round, leaving a slightly rough finish, but it's foam, so that doesn't really matter.
One of the rarely but occasionally handy accessories I've got for my lathe is a live centre with an M33 thread on the end. When I'd removed the bowl from the lathe after doing most of the turning, I'd left it in the chuck and just removed the whole lot. I mounted the chuck on the M33 live centre and put that in the tailstock. I could then push the tailstock up against the foam block, compressing it rather a lot:
The foam block provides the transfer of the motive force, the chuck in the live centre keeps everything concentric, at least until I cut all the way through the Sweet Chestnut block at which point I would expect the bowl to go flying across the workshop!
I took it quite gently, stopping every now and again to see what it was looking like:
I'd mostly finished the bottom surface before gluing the Sweet Chestnut on, so in an ideal world I'd just remove the Chestnut and glue and leave an immaculate surface, but I'm not that good at turning! Has anyone on here ever tried turning a bowl with a sacrificial base held on with a couple of layers of masking tape and some superglue? It'd be quite easy to get off of course, but I'm a bit nervous about whether it'd hold well enough for hollowing out the inside of the bowl.
A bit more progress - you can see that a downside of this holding method (rather than just using a live centre into a centre dot) is that the chuck stops the rest from getting close, although it didn't seem to be too much of an issue:
This is the point that I decided to stop:
I took it off the lathe and used a Dozuki to saw off most of the sacrificial block, leaving this much:
Most of that got removed with the 80 grit sanding disc on the lathe spindle (visible in the background of the photo). The last bit got removed with a random orbital sander, using a bit of plywood as a temporary work surface:
I've found my Mike's Magic Mix now so I used that for the finish. It's had one coat so far:
Side view:
I found the process of turning away the sacrificial piece without the Cole Jaws a bit daunting but it worked quite well all things considered. Perhaps next weekend I'll psyche myself up to turning the big Ash blank into a fruit bowl.
- Rob
