Roughy re-handle and SO bowl

[Robomanic]

After the natural edge Redgum bowl I finished a couple of weeks ago, I decided that my 20mm roughing gouge needed a new handle.

87728

I got itchy fingers and decided to do some damage to a SO blank that Ern gave me a while back.

87729 87730 87731

As a number of experienced folk predicted, my chute and dusty quickly got overwhelmed with the curlies and the chute was removed (it was getting a bit soggy too :oo:) It still managed to collect some shavings though :doh:

87732

Very happy with the new length and the bowl seems alright, but I have some questions...

- Does the rim look thick/thin enough? It is a uniform 30mm from lip to base (plus the 5mm tenon on the base). Is the 1/10th diameter rule close enough or is it timber specific?

- It is packed in a material bag with shavings to slow down the drying. I have filled the bowl and then 'hollowed' the shavings out so that there is not many covering the bottom, leaving a lot around the rim. Waste of time? Thinking that the base could do with more exposure than the lip. Any thoughts?

- Was it a mistake to leave the sapwood on?

The mc1100 stood up ok, but the legs will be getting replaced. Compared to some previous posts, the keen observer might see a lot more ballast on board for this one :o. A sand-filled heavy RHS stand with lugs to take a 1/2" dynabolt is on the cards, which should help a lot.

Any comments or tips are greatly appreciated :)

[tea lady]

Looking good Shannon.:2tsup: Bigger handles for roughing gouges are much better in my mind. They hane to be able to reach your hip.

As for the bowl, are you going to turn it again when it is dry? What is this rule of 1/10 the diameter? Is that just for wet turning? :?

[Robomanic]

Looking good Shannon.:2tsup: Bigger handles for roughing gouges are much better in my mind. They hane to be able to reach your hip.

As for the bowl, are you going to turn it again when it is dry? What is this rule of 1/10 the diameter? Is that just for wet turning? :?

Thanks,
Yep - the plan is to re-turn it after it dries (prob should have mentioned that :doh:)

I think I picked up the rule from a Richard Raffin book somewhere. For wet turning the idea is to leave a wall thickness of 1/10th the bowl diameter, and it should leave you enough to turn it true after drying.

I was tempted to finish it wet but I am not there yet (and decided to play it safe after mounting this basically square)

[robutacion]

Hi Robomanic,

For a green rough turning, is good enough. It has enough "meat" thickness to allow for a considerable amount of "twist & turn" while drying! :D

I found very effective and safer to coat the green turnings with some timber stabiliser, such as the one I use, Fungishield from FeastWatson before I store them to dry. I don't have much testing done with green timbers drying in sacs with their own shavings, but I believe that it works quite well, others will be able to expand on it a little more or a search on "green turnings" will produce some good results.

PS: I like big handles also, obviously...!

Cheers:2tsup:
RBTCO

[Grumpy John]

For wet turning the idea is to leave a wall thickness of 1/10th the bowl diameter, and it should leave you enough to turn it true after drying.


Hi Shannon,
I find that the 10% rule of thumb works pretty well for most timbers, however I'll probably leave 50% on the next Melaleuca bowl I do :D

[hughie]

The mc1100 stood up ok, but the legs will be getting replaced. Compared to some previous posts, the keen observer might see a lot more ballast on board for this one :o. A sand-filled heavy RHS stand with lugs to take a 1/2" dynabolt is on the cards, which should help a lot.



Defintely,defintely change the legs etc. No matter how much you load up the bottom tray with extra wieght the legs will still flex badly......:~ I had the best part of a 100kg on mine and it still danced around and I could see the legs flexing. :o :C

So I threw it out and built a new but rather substantial one from 200x65 Oregon and 20mm plywood. The legs are hollow to allow sand ballast, I reckon 150-200kgs in both. Then I will be fitting flexible type feet similar to MRI scanners..courtesy of
Stu-in-Tokyo. :U

[Robomanic]

Hi Shannon,
I find that the 10% rule of thumb works pretty well for most timbers, however I'll probably leave 50% on the next Melaleuca bowl I do :D

Hahaha,


Then I will be fitting flexible type feet similar to MRI scanners..courtesy of
Stu-in-Tokyo. :U

Can you elaborate? I was going to bolt mine down with car tire tread between the foot and the concrete to give it a little flexibility. The poor headstock bearings might last a little longer that way.

[hughie]

[




Can you elaborate? I was going to bolt mine down with car tire tread between the foot and the concrete to give it a little flexibility. The poor headstock bearings might last a little longer that way


In order to contain vibration you have to mechanically isolate it. If you bolt your machine down with a rubber pad between the machine and the floor, this is not mechanical isolation, as the bolts still make the connection. Its a bit like a electrical connection.

MRI Scanners feet are a sandwich of materials. I used wood,cork and rubber ie

wood-cork-wood-rubber all glued to gether to form one solid block. This I fixed to the lathe stand as the feet. This then isolates the vibration from the floor and the cork/rubber has a degree of vibration absorbtion, plus the additional wieght I have placed on the lathe. sori no pics as the lathe is in mothballs awaiting the new shed to be built.

[Robomanic]

yep you are right Hughie, left out an important bit.

There will be two layers of rubber. Concrete -> rubber -> steel plate foot -> rubber. The bolt goes through the lot and the nut screws down on top of the top piece of rubber. This way the foot can float (a little) between the two layers of rubber, while the bolt is holding the whole assembly down firmly.

[rsser]

My band-sawn lumps of SO are checking in the sapwood. The rough-outs have no sapwood and look fine: all end grain and knots are sealed with paint-on goo. I've gravitated to this after trying things like you've done here.

On another thread folk have recommended removing all sapwood. With dry SO blanks I've not found a prob with the sapwood but all I can say is check your rough-out every day. This log was wet beyond the scale on my el-cheapo moisuture meter: > 35% (but that's not correcting for density; see the scales in Bootle).

Another option is to completely finish-turn green in one session (do a search for tips). This will give you a somewhat oval bowl which may or may not be found attractive.

With Helmut's bowl at 's turn-on a widish rim revealed the lace figure that quarter-sawn SO and similar are renowned for so you might consider this for your second rough-out.

Best of luck Shannon.

[Robomanic]

I check it like you suggest and maybe I'll finish it green on the weekend. Knew it was very wet and did not want it to warp as I was turning it. SWMBO likes round ones better too so if it lasts the distance I would like to finish it dry.

[turnerted]

Shannon
If you get impatient to finish your bowl , weigh it every week or so and when it seems to be no longer distorting and the weight is only dropping by about 10gm or so every time you weigh it ,Rough turn it again just leaving the wall about say 5mm thicker than you want to finish it , then it will dry a lot quicker then you can finish it .
Ted

[rsser]

To green turn to finish is a whole other ball game.

Don't mean to suggest you can't change codes mid-way, and go for it if you want to; just read up on green turning.

[Robomanic]

Shannon
If you get impatient to finish your bowl , weigh it every week or so and when it seems to be no longer distorting and the weight is only dropping by about 10gm or so every time you weigh it ,Rough turn it again just leaving the wall about say 5mm thicker than you want to finish it , then it will dry a lot quicker then you can finish it .
Ted

Thanks Ted, sounds like good advice.

[Robomanic]

Cracks started to appear in the sapwood after a hot day in the shed, so decided instead of letting them propagate through I'd finish it wet.

Here is the finished article, Fingers crossed ~10mm it is thin enough and it will dry slowly enough to warp and not crack.

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Thanks for the interest everyone.

[artme]

Looks great Shannon.:2tsup::2tsup::2tsup:
Sure hope there is no more splitting or cracking. Perhaps if you store it in a cbinet for a time this will help.

[Ed Reiss]

:2tsup::2tsup:top notch, Shannon!

[Robomanic]

...
What'd do you finish it with Shannon?
...

A lesser of two evils I am afraid. Had a choice between Wipe On Polly or Organ Oil Wax polish. I didn't want to risk the WOP over such green wood because I thought the sap might foul up the drying/hardening. I would go for danish oil next time if I had my choice but any suggestions are welcome.

[rsser]

Green wood - I use nitrocellulose sanding sealer followed by wax.

Though by the time they're ready for finishing many bowls are close to dry.

Raffan recommends waiting til they are dry; if you use a recess mount in the foot you can then mount 'em in the lathe to make it a bit easier. Course if they go oval you have to spin slow if not at all.

[rsser]

To add: not tried it but can't see why you couldn't use a few coats of weak White Shellac. The meths would combine with any moisture left. Though the wax may not bond too well straight away.

Of course, if you don't mind a bit of darkening, then use normal shellac.

Some folks hit the surface with a heat gun to get the surface dry quickly. Not tried this either ... and would be wary of doing it on desert acacias (not that we come by those green much in Melb.).

Hope this helps.

Edit: I get the n/c sealer from The Woodsmith in Melb for about $22 a litre. Pour say 200 ml into a jar, add 100 - 200 ml of auto paint thinners, drop a short brush into it (shortening the handled if needed) and then for application: paint the piece with it, wipe excess off with a rag and then cut it back with 0000 steel wool. Cap the jar. If in a rush, drop the rag stage. In under a minute I'm ready for the next stage).

Edit 2: BTW, if you sign the foot of your work with a felt tip pen, do it after the n/c sealer goes on. DAMHIKT! (With an oil finish, do it on bare wood).

[Robomanic]

I did dry the surface but it seemed to only last minutes before more moisture leached out from underneath.

(if any of the moderators are interested - would you like to move the posts concerning my particular piece to here:
http://www.woodworkforums.com.au/showthread.php?t=81827
please?
That would be posts 60, 61, 62 and this one.

[DJ’s Timber]

(if any of the moderators are interested - would you like to move the posts concerning my particular piece to here:

:2tsup:

[Robomanic]

Man, he IS always watching... :2tsup: thanks DJ

[rsser]

Onya DJ.

[tea lady]

Should at least leave a link to the other thread. :)

[DJ’s Timber]

Should at least leave a link to the other thread. :)

Done :2tsup:

and reciprocal link back to Gallery thread (http://www.woodworkforums.com/showthread.php?t=83777) as well :; :U