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Grumpy John
28th June 2008, 05:29 PM
G'day All,
I am keen to turn some natural edge bowls and have already "googled" turning natural edge bowls and have book marked 5 sites that give plenty of information. What I would like to know from any forumites that have turned NE bowls is are some timbers more suited to having a natural edge. Does the bark have remain on for it to be a NE bowl. Are there any hints or "tricks of the trade" that could be passed on. I plan to do a WIP of my first bowl and will post pics when I find a suitable log.

http://www.woodworkforums.ubeaut.com.au/showthread.php?t=74872

Cheers
GJ

Caveman
28th June 2008, 06:06 PM
G'day GJ,

Have done several NE bowls - I reckon they generally always look better with bark still on, but unfortunatly this is sometimes impossible.

One species that still seems to look good without the bark is Casuarina - seems to be very rough under the bark anyway.
The pics are of a C. cunninghamiana that I rough turned very wet then dried out for several months - a little bit of spalting occured under the wax coated after roughing out which resulted in the black streaky marks:shrug:.

They generally require a fair bit of sanding with the lathe stationary on the 'wings' (power sanding makes it nice and easy).
Other than that keep those knuckles on your side of the tool rest whilst it's spinning and you should be ok:oo:.

Calm
28th June 2008, 09:23 PM
John i have tried a couple and found the hardest part was getting the right log so it ends up balanced with both "wings" equal. The bark looks good but i dont see it as a major point.

Good luck they are a real buzz when they come out right.

weisyboy
28th June 2008, 09:53 PM
i love nat bowls

so easy just cut the log inhalf and stick it on the lathe.

working out how to mount it is the hardest part to start with but otherwise its easy.

sanding can be done with the lathe running just aproch the edge with caution with the bottom of the paper touching firest to avoid losing fingers.

go for it.:2tsup:

joe greiner
28th June 2008, 10:00 PM
One trick I've found helpful is to dribble some CA glue on the bark and cambium (thin layer just under the bark) to preserve most of it. The CA can be the final finish on the bark itself. Wear proctologist gloves at this step, and wipe with the lathe stationary. A lint-free rag works better here than a paper towel, because it doesn't leave tiny bits of paper to remove from the bark. You may need to repeat as turning progresses, and usually best to cut away any parts of the underlying timber until CA no longer shows there - just for appearance, unless the whole piece is destined for CA finish.

Tool bounce can be a problem when cutting air, timber, air, timber, ... And sandpaper chatter too. Expect to do some tedious hand sanding, or very gentle power sanding. Dremel with a disk or drum sander can reach into tight spots, but high speed requires an even more gentle touch. (Dremel at its lowest speed.)

The irregular NE can prevent use of Cole jaws or Longworth chuck for finishing the bottom. A vacuum chuck with a central pad would probably be best for this. But without a vacuum chuck, you can make the tenon long enough to undercut most of it, as if the piece were a goblet, and cut off the last of the nubbin by hand. Or, use a jam chuck with support from the tailstock to finish most of the bottom, and again cut off most of the nubbin by hand.

Joe

funkychicken
28th June 2008, 10:19 PM
Mounting is easy; I drill a hole in the bark side in which the chuck jaws go. Then stick it on the lathe of course

Calm
28th June 2008, 10:41 PM
Mounting is easy; I drill a hole in the bark side in which the chuck jaws go. Then stick it on the lather of course

Then what shave it????:D:D:D:doh:

rsser
29th June 2008, 02:31 PM
Have tried Olive, Banksia, Almond (the nut), Red Mallee Burl and Walnut. The bark on the last two tended to fly off.

Like Joe, I've used CA to hold bark on but the drawback is that you either get a narrow dark line of it or else you have to treat all the bark and that darkens it considerably which can make it look silly.

NeilS
29th June 2008, 09:02 PM
Further to the useful comments from the others:


I use a large Forstner bit to create an initial recess in bark side for deep chuck jaws to grip or for small faceplate to seat
Often don't halve log when retaining natural edge, espeicially on smaller diameters. Halving log results in quite low sides at the low point of the dip which, in my case, can look a bit floppy if not carefully resolved. Working with full log offers more scope for fuller forms and lift.Neil

Calm
29th June 2008, 09:11 PM
Further to the useful comments from the others:

I use a large Forstner bit to create an initial recess in bark side for deep chuck jaws to grip or for small faceplate to seat
Often don't halve log when retaining natural edge, espeicially on smaller diameters. Halving log results in quite low sides at the low point of the dip which, in my case, can look a bit floppy if not carefully resolved. Working with full log offers more scope for fuller forms and lift.Neil

Very good comments Neil,

i will try the hole next time as i see it gives a better chance of getting the natural edge balanced/equalised better. The other one i'm not sure of leaving the pith n the bowl. still worth a try.

cheers

Grumpy John
29th June 2008, 09:11 PM
Further to the useful comments from the others:

I use a large Forstner bit to create an initial recess in bark side for deep chuck jaws to grip or for small faceplate to seat
Often don't halve log when retaining natural edge, espeicially on smaller diameters. Halving log results in quite low sides at the low point of the dip which, in my case, can look a bit floppy if not carefully resolved. Working with full log offers more scope for fuller forms and lift.Neil

How do you hold the log whilst creating a recess with the Forstner bit, or do you use the Forstner bit in a drill press and clamp the log to the drill table?

Chipman
29th June 2008, 09:17 PM
That would be the forstner bit in the drill press John


Chipman:)

TTIT
29th June 2008, 11:39 PM
Very good comments Neil,

i will try the hole next time as i see it gives a better chance of getting the natural edge balanced/equalised better. The other one i'm not sure of leaving the pith n the bowl. still worth a try.

cheersGive it a go David. I've done a few with the pith involved and had no problems - even some timbers that are reknown for splitting. Seems as though hollowing down to a thinnish wall relieves enough stresses to allow it to stay intact.
All good advice NeilS:2tsup:

Grumpy John
30th June 2008, 11:26 AM
That would be the forstner bit in the drill press John


Chipman:)

Thanks Chipman, that's what I figured but I never fail to be surprised by the ingenuity of the people on this Forum. Just remember there are no stupid questions, just stupid answers.

NeilS
30th June 2008, 08:35 PM
do you use the Forstner bit in a drill press and clamp the log to the drill table?

Yes and yes.

Neil

NeilS
30th June 2008, 09:11 PM
I've done a few with the pith involved and had no problems - even some timbers that are known for splitting. Seems as though hollowing down to a thinnish wall relieves enough stresses to allow it to stay intact.

Yes, that's also my experience and if any fine cracks do develop from the pith they will radiate out in a pleasant way from the pith centre like medullary rays and, if an issue, are readily sealed with SG.

Neil