Had an enjoyable afternoon in the shop as I'd some Xmas presents to make, one of which was a bowl made for a 200+ year old Sycamore blank from the old grounds of the Buxton grammar school.
While I was turning it I took some photos just in case anyone wanted to see how I go about turning a bowl from what was a very dry spalted blank. I would say from the start this is my way, there are other ways & I'm definitely not saying it is the best way, just how I feel comfortable going about turning it.
First off the blank is held in the chuck via a threaded screw drive & the outside shape is turned along with a spigot, no sanding is done yet.
This is then reversed & held in 2" jaws & the inside hollowing begins, when about 1" or so in & while there is still plenty of support as not much timber has been removed I finish that first 1" of the inside of the bowl with a scraper until I'm happy there is nothing that can't be removed with 240 grit.
I continue doing this roughly every 1" as I proceed hollowing out. As can be seen in the next photo due to the dryness & spalting of the blank there is quite a lot of tear out in the rough hollowing even though I was using a shape bowl gouge.
If I'd hollowed the complete bowl & then tried to clean up the insides with a scraper chances are I'd get a lot of vibration as the mass would have been removed & as the sides are quite thin I would have been left with an unsatisfactory finish.
Once happy with the inside shape & finish off the tools I sand both the inside & outside of the bowl. I find if I start with too course an abrasive I get scratch marks that are very difficult to remove so I try to get a tool finish that is good enough that I can start sanding at 240 grit.
I work down the grits to 600, as this is going to be finished on buffing wheels 600 is fine but I do give the bowl a coat of cellulose sanding sealer as this shows up any scratches I may have missed.
Happy with the finish the bowl is reversed again & mounted in cole jaws. The tail stock is bought up just as a precaution, my mandrel saver being ideal just to prevent any bowl movement away from the jaws, I can then remove most of the spigot.
The last remaining bit is cut off with a saw & the bottom sanded, then it's over to the buffing wheels to cut back & polish.
The finished bowl.
Hope this is of some use to a few of you, I know there are plenty out there with far more experience than me, but I thought whilst I was turning this I'd share how I go about things.
While I was turning it I took some photos just in case anyone wanted to see how I go about turning a bowl from what was a very dry spalted blank. I would say from the start this is my way, there are other ways & I'm definitely not saying it is the best way, just how I feel comfortable going about turning it.
First off the blank is held in the chuck via a threaded screw drive & the outside shape is turned along with a spigot, no sanding is done yet.
This is then reversed & held in 2" jaws & the inside hollowing begins, when about 1" or so in & while there is still plenty of support as not much timber has been removed I finish that first 1" of the inside of the bowl with a scraper until I'm happy there is nothing that can't be removed with 240 grit.
I continue doing this roughly every 1" as I proceed hollowing out. As can be seen in the next photo due to the dryness & spalting of the blank there is quite a lot of tear out in the rough hollowing even though I was using a shape bowl gouge.
If I'd hollowed the complete bowl & then tried to clean up the insides with a scraper chances are I'd get a lot of vibration as the mass would have been removed & as the sides are quite thin I would have been left with an unsatisfactory finish.
Once happy with the inside shape & finish off the tools I sand both the inside & outside of the bowl. I find if I start with too course an abrasive I get scratch marks that are very difficult to remove so I try to get a tool finish that is good enough that I can start sanding at 240 grit.
I work down the grits to 600, as this is going to be finished on buffing wheels 600 is fine but I do give the bowl a coat of cellulose sanding sealer as this shows up any scratches I may have missed.
Happy with the finish the bowl is reversed again & mounted in cole jaws. The tail stock is bought up just as a precaution, my mandrel saver being ideal just to prevent any bowl movement away from the jaws, I can then remove most of the spigot.
The last remaining bit is cut off with a saw & the bottom sanded, then it's over to the buffing wheels to cut back & polish.
The finished bowl.
Hope this is of some use to a few of you, I know there are plenty out there with far more experience than me, but I thought whilst I was turning this I'd share how I go about things.