HELP!....please!

[Les Symonds]

I was playing this morning, with some ash that I cut down for firewood, but decided that at least some of it might work its way into the workshop. Whilst I've pottered about with bits of 'damp' wood and have tackled the occasional natural edge, this was the first time that I'd gone the whole-hog and mounted a big lump of dripping wed log on the lathe.

I guess that the idea was to just have a bit of fun and get a feel for working like this, but I got carried away and a nice looking bowl began to emerge from the shavings that I was producing. I decided to try to salvage the bowl, if only as a gift for family/friends....but I hit a few problems and could do with a bit of advice. So here's a few questions.....
1. with a shape like this, how do you manage to roll the bowl gouge around the inside without, as the point of the gouge gets deeper down into the bowl recess, snagging the shaft of the gouge against the rim?
2. how do you measure  the depth of the bowl so that you know how deep to cut the bowl itself, and how deep to recess the foot. I found this especially difficult once I'd reversed the bowl onto a dolly and brought the tailstock up against it. Assessing how deep to cut the hollowing of the foot was quite a mystery!
3. roughly how long do these take to dry out....this bowl is 7" deep x 8.5" diameter, with a wall thickness of 5mm
4. I've sanded down to 400 grit, but I imagine that as moisture reaches the surface and evaporates, it's going to raise the grain. So, what's the normal regime for this sort of turning?
5. finally....how on earth do you apply the rule of thirds to a shape like this....with such a random shape to the height of the rim, how do you decide what is one-third of the height?

I'd love to save this bowl....given the effort that I've put into it, and I know it will not be good enough to sell, but my son has seen it and wants it, as does my wife and a friend who just called in.....so any help that you guys can give will be appreciated. By all means be critical....I won't be in the least bit offended.







Les

[woodndesign]

Les, You could give it a coat of oil to slow the drying .. also/as well store in cool, dry and air place, even a cool room in doors, you can weigh the piece and note water lost as weigh decrease till stabilized.

A really nice piece .. Down to hand sanding if necessary ... Finally make two more and have them fight over which they like ..

If you lose any it was firewood ...

Cheers  Dewi

[Paul Hannaby]

Here's my answers - not necessarily the only solution!

1. with a shape like this, how do you manage to roll the bowl gouge around the inside without, as the point of the gouge gets deeper down into the bowl recess, snagging the shaft of the gouge against the rim?
Use a gouge with a steeper bevel, i.e. 60° or more if necessary. This will have the effect of moving the gouge away from the rim. In extremely narrow/deep bowls you may find the only solution is to switch to a hollowing tool instead of a bowl gouge.
2. how do you measure  the depth of the bowl so that you know how deep to cut the bowl itself, and how deep to recess the foot. I found this especially difficult once I'd reversed the bowl onto a dolly and brought the tailstock up against it. Assessing how deep to cut the hollowing of the foot was quite a mystery!
The simple answer to this one is you don't! I usually use a set of calipers to measure the wall thickness of the bowl. The vessel calipers with one straight leg and one curved leg are particularly useful because you can put the straight leg between the chuck jaws and measure the thickness all the way to the middle.
3. roughly how long do these take to dry out....this bowl is 7" deep x 8.5" diameter, with a wall thickness of 5mm
It will depend to some extent on the type of wood and the environment it is in but at a guess, a couple of weeks to a month for a 5mm wall thickness. The thinner you make the wall, the faster it will dry.
4. I've sanded down to 400 grit, but I imagine that as moisture reaches the surface and evaporates, it's going to raise the grain. So, what's the normal regime for this sort of turning?
Probably not worth sanding it until it is dry but you could go for the other option and wet sand it to a finish. That way the grain shouldn't get raised as the wood dries.
5. finally....how on earth do you apply the rule of thirds to a shape like this....with such a random shape to the height of the rim, how do you decide what is one-third of the height?
Some rules are made to be broken so don't lose any sleep over it!

[TWiG]

I rarely turn bowls this shape as I find it very awkward for the reasons you have given , however I can concur with P Hannaby ... use a different grind on your bowl gouge , or a hollowing tool with a scraper tip in a shear scraping mode , and then prepare to sand more than usual !!! as for drying ... I turn a lot of hollow vessels from green wood and turn , sand ,and finish when still green ( sometimes I dry the surface with a blowlamp .. carefully ! ) and always get a good finish with the added benefit of some surface texturing , especially with burrs , when completely dry , I  NEVER do this in summer ...   This will vary considerably with different woods , The large foot you have left on this piece may will give you problems though but should be easy enough to re-shape / re turn once it has finished its distortion and hopefully not split ... personally I would have turned a much smaller foot for a more pleasing form ( to my eyes anyway )  ... however its fun playing at different things .. Terry...

[The Bowler Hatted Turner]

Hi Les,
            I can't add much to what has already been said, just feel happy that you are turning what a lot of people do not.
Regards
John BHT

[Les Symonds]

Cheers, guys, for all the advice. One question, Terry....in view of the fact that you're applying a finish over moist material, I was wondering what sort of finish you apply.....presumably an oil!
Les

[TWiG]

Yes   Liberon finishing oil , takes a few coats to get a good satin lustre , but getting one coat on fairly quickly really slows the drying rate , I usually need to sand with 600 grit once the  piece is completely dry and then apply 2 more coats for my desired finish . You have to sand pieces made from burr almost straight away  or or the surface becomes so uneven ( which I really like ) it would be almost impossible to sand once the wood is dry and distorted , so I found it works OK for burr wood I do it to most others as well now .  Terry...

[Les Symonds]

hi Terry...do you ever use Danish oil....just wondered how the two compare?
Les

[Bryan Milham]

Les,

Your questions have been answered very well so all I can add are the couple of things I sometimes do differently.

I use Lemon Oil on wet timber. I can't actually give a reason except it's thinner and I therefore think it penetrates easier (someone correct me). I leaves a matt finish but this can be re-finished once the wood is dry with thicker Danish and other finishing oils etc. The other thing is it stinks like kerosene, so be prepared to have it sat around in the workshop for a week or so while the smell dissipates.

The other thing is sanding inside the bowl. You'll find that it's difficult to get that deep inside. I found the easiest method was to make my own sanding arbour. You will have seen images of people putting the arbour into a Jacobs chuck (1st Image) or a wooden holder. My method is to purchase some 50mm Hook & Loop (Velcro) and make my own extended arbour (2nd Image). I have several so I can reach any length into a form I need and also if you touch the form on the rotating arbour it's wood, not metal.

[Les Symonds]

Thanks, Bryan....I like that idea....I might try turning a similar shape, boring it and setting a steel rod into the centre of it, so that I can mount it hanging down from my pillar drill. That way, I could set the table down, out of the way, and work the bowl at a convenient height and be able to see into it.
Cheers...Les

[Richard Findley]

Hi Les

There is an article by Mark Sanger that you would find interesting in the latest Woodturning Magazine. He discusses design (including plenty on using the thirds 'rule') also a good depth gauge design.

Regarding bowl gouge angles, I have an ongoing 'discussion' with a professional woodturner friend of mine. He swears by using a 45 degree angle and constantly tells me that my 60-65 degree gouge is useless. Personally I find a roughly 60 degree grind on a bowl gouge with the wings ground back a little way, to be the most versatile grind which does for most bowl designs. The problem with the longer grind is that, as you found, it is very restrictive on all but the most basic bowl. A 45 degree gouge may cut slightly better but then you need a number of other gouges to do other jobs and other shapes.

There is more about my bowl gouge in the previous months Woodturning Magazine.

Hope this helps

Richard

[Les Symonds]

Thanks Richard....I've been getting by with just the one bowl-gouge, but had a second one for a Christmas present....maybe I'll rethink the 'angle issue' before I re-grind it (at the moment, it's square-ground).
Les

[ken rodgers]

Hi Les,
Like Bryan stated I also use Lemon Oil on most off my turnings especially those from wet/green wood. I apply a very heavy coating of the oil which I find penetrates the wood very quickly, leave for about half a hour and coat again, then leave to dry in a cool well aired environment.
After a few days another coat of oil is applied and wiped off and this is repeated for several weeks.
I have been doing this for sometime now and have not experienced any pieces cracking/splitting - wood used being Holly, elm, oak sycamore, beech and cherry
Regards
Ken