Which tool??

[Grumpy John]

Merry Christmas and a Happy New Year to all

I have recently come across some banksia cut down late December (06) and have been busy roughing out bowls and storing them in rubbish bins filled with shavings.
I am attempting to do a "closed in" (is that the correct term) bowl and was wondering what is the best hollowing tool to use for a bowl of this size.
Also does banksia react badly when dried in a microwave?

Thanks in advance
GJ

[Speanwoody]

I have used this tool to do hollow forms to date and it works okay see attached spalt ash hollow form its about 4.5 inches high, http://www.cws.au.com/cgi/index.cgi/..._id=1107370094

[Skew ChiDAMN!!]

I use a home-made tool for the major hollowing and use a Sorby Hollowmaster (the same as SpeanWoody) with custom tips to get up under the lip and "hard to access" places. But don't get hung up on brand-names; any good goose-necked tool would do the same job, once you master using one.

Banksia? I've found that to be one of the woods that're really prone to checking. I've yet to have a large(ish) piece that hasn't split during normal air-drying, regardless of how well I seal it. I've had moderate success with microwaving Banksia pen-blanks, but I haven't tried nuking larger pieces. Yet.

If you nuke yours, I'd be interested to hear how it goes! The pictured bowl looks to have some seriously nice figuring, don't forget to post pix of the finished piece!

[turnerted]

Hi
I have used Bruce Leadbeatter's hollowing tool with some success for jobs like this . Google for him for details on his web site or ring him on 0297185395 .
I havn't tried it on banksia .

Ted

[Grumpy John]

Hi Skew
I've been seriously thinking of getting the Sorby hollowing tool since I had a go at making one. I didn't realise that there was a flat on the botton and mine is all round and it "rolls over" when I take a cut. The bar is only 12mm dia and is too small to machine a flat on it.

[rsser]

For reviews of hollowing tools, see http://www.fholder.com/Woodturning/lyn.html

I'd be hollowing those pieces asap; the most reliable drying results come from pieces with even thickness walls.

Only done one bit of Banksia, and some Hakea, and both were prone to cracking, so keep a sharp eye on yours and if it starts then seal the end grain or wrap in shavings in a plastic bag and hollow as soon as you can.

[Skew ChiDAMN!!]

I've been seriously thinking of getting the Sorby hollowing tool since I had a go at making one. I didn't realise that there was a flat on the botton and mine is all round and it "rolls over" when I take a cut. The bar is only 12mm dia and is too small to machine a flat on it.

Mine doesn't have a flat either... but it is quite a few years old. One of the first off the production line, I believe. (Second hand = cheap. ) The flat may be a new refinement?

So long as the cutting edge of your bit is aligned with the straight edge of the shaft, it shouldn't matter whether it has a flat or not. I like to roll mine, so a flat would be more of a hindrance than anything!

You do know that you should only rest the straight section of the shaft on the toolrest, not the curved arc? Otherwise it will roll over every time, because of the leverage on the tip. This means a lot of tool overhang over the toolrest and to make up for that I rehandled mine with a handle twice the length of the stock one. (I consider that a "fault" in the Sorby design. ) It also means increased chance of chatter, but I guess that forces you to learn proper techniques. ie. Sharp edge and light, shearing cuts.

Frankly, your tool looks to be perfect for the job! Just a matter of getting used to the foibles of goose-necked tools.

For reviews of hollowing tools, see http://www.fholder.com/Woodturning/lyn.html

Thanks for that link, Ern. Another one to add to the collection...

[Grumpy John]

Hi Skew
The overall length of my hollowing tool is approx 400mm (16") but the handle is only 20mm (3/4") dia. Maybe I should make a bigger handle for it before I part with $100+.

cheers
GJ

[Skew ChiDAMN!!]

I wouldn't worry about the dia. of the handle so long as it's comfortable to your hand; the length is what is important. Every inch longer gives that little extra piece of control.

For example, let's say that the arc part of the shaft is 4" long and that, when first starting the undercut, you're resting the start of the curve on the toolrest, then you have 12" of "effective handle" (in a 16" tool), giving you 3:1 leverage. Even that's not really enough for my taste... I'd much prefer 5 or 6:1. So, I'm a weedy bloke.

But as you go deeper, say you have 8" of tool overhanging the rest, then you only have 8" of handle and 1:1 leverage. Trust me, the lathe is stronger than you and will win every argument.

I'd rather have a 3' handle that's normally "too long" (except for really deep hollowing) than a handle that's "too short" all the time.

Sorry if I sound like I'm lecturing... I just thought I'd add an explanation of the "why's" for anyone else who may read this thread.

[Grumpy John]

Skew
Thanks for the heads up on the dynamics of using a hollowing tool . I think I'll make a longer and thicker handle and knurl it for better grip. I'm using aliminium for the handle because I have several other tools I interchange using a couple of grub screws.

Cheers
GJ