First big bowl - accident recovery !

[OldWood]

This was one of those "Oh b$%^&*r !!", etc. moments. My first attempts at a bowl greater than my normal 6". I'd got hold of some larger section maple which is all flame and early rot which turned well, but I got the control of my measurements wrong when turning out a 10" piece and have gone through the bottom . I will not in future take 2 bites with the 6mm drill for depth as clearly this adds to the danger !

Anyway I'm sure that there will be someone who has done similar and decided the shape and previous turning was good enough to attempt "the incorporation of a feature" as a repair. Any guidance please. I could re-invent the wheel but I'm sure plenty have done it before me.

Thanks
Rob

 

[gus3049]

Happens quite often I suspect.

The usual way I've seen is to add an 'accent' in contrasting wood (unless you can match exactly in the same wood!!

A bit of yew with a 'walnut accent' attached! Now its finished and oiled I've almost forgotten I didn't add it on purpose

 

[boysie39]

Gee thanks Gordon,
I have about three weeks work in the Shed now.
UKW always something to learn.

 

[chrisbaker42]

I had a similar problem with a nice ash bowl and did not wish to turn a nice large piece into firewood. It now has a very nice mahogany foot which was glued in place and then returned to the lathe for the returning of the inside.

 

[Jonzjob]

I have never had the silly embarassment of going through the bottom of a bowl y accident. This was a feature

So was this

I thought that I had photos of a couple more too, but I can't stop to find them now as i have been trying to get a photo of a pig flying past our window :roll: :roll: :roll:

 

[boysie39]

I have never had the silly embarassment of going through the bottom of a bowl y accident. This was a feature

So was this

I thought that I had photos of a couple more too, but I can't stop to find them now as i have been trying to get a photo of a pig flying past our window :roll: :roll: :roll:

I knew it, I knew it, and nobody would believe me, and me after giving up the drink an everything .

Tanksh berry mush john.

 

[gus3049]

And of course, if one tries to make the walls a little too thin on hollow forms.......


.....one can have a very small er..... whatever it is indeed. I'll sell it as a jewelry bowl or an egg cup for goose eggs. Its nice Box wood so it feels good - small but imperfectly formed, this bit wots left is almost 3" high #-o .

 

[OldWood]

Ah, good - and I see that all the 'good' turners do it too, so at least I get some comfort not being in that classification myself.

Unfortunately the bottom of the bowl had developed a rather over-turned internal shape so the plug had to be a stepped affair - I cut a disc off a laburnum bough which I've just glued in, so I'm hoping that it will be a nice feature. All the extra work will encourage me not to do it again - hmm, I wonder how long that will last ?

I'll post a picture when it's done.

Rob

 

[Jonzjob]

What I do when I 'design' such a 'feature' like that into a bowl is to cut a tapered hole just a little smaller than the chuck jaws, mounted and spinning obviously, turn a tapered plug so that the bottom of the taper is as close as I can get it to the underside of the bowl, glue it in place and when the glue is dry turn it down to match the bowl without going through the bottom again!

Good-ere-init!!

 

[gus3049]

Ah, good - and I see that all the 'good' turners do it too, so at least I get some comfort not being in that classification myself..............

..........all the extra work will encourage me not to do it again - hmm, I wonder how long that will last ?

Rob

Hmmmm, not sure who these 'good' turners are! Must be Jonzjob, I am but an egg.

It seems to go in patches, p'raps its the weather or the phases of the moon. I managed my first eleven months of turning without a single similar mishap. In the last six weeks there have been..... er.....shall we say 'several' small mishaps that have lead to design opportunities.

Actually it may be a matter of confidence. Now I am old old hand at this game, I know of course that I can do it well, do it quickly, and do it wrong.

 

[OldWood]

What I do when I 'design' such a 'feature' like that into a bowl is to cut a tapered hole just a little smaller than the chuck jaws, mounted and spinning obviously, turn a tapered plug so that the bottom of the taper is as close as I can get it to the underside of the bowl, glue it in place and when the glue is dry turn it down to match the bowl without going through the bottom again!

Good-ere-init!!

That does assume that there is enough depth of wood in the hole for a taper to be effective. I'd drilled in from the top to give me a depth marker and because it was a bigger bowl than I'd done before, the initial hole wasn't long enough and had to be taken out of the backcentre chuck and extended. It must have stopped about 0.5mm from the base as the failure was quite large diameter and thin. So I cut back an area of the inside flat and made a 70mm dia infill with a 35mm dia tenon on it to fill the tidied up hole and large enough to glue to the inside. Time consuming - I'm away off now to see if it will work !

Thanks for all your support, guys.

Rob

 

[Jonzjob]

Backc entre chuck? Is that a screw chuck?

Now look 'ere Rob, if you are going to throw difficulties and excuses in here? Just use a shallower taper! No probs with a 1/64" depth :roll: :roll:

 

[OldWood]

Backc entre chuck? Is that a screw chuck?

Now look 'ere Rob, if you are going to throw difficulties and excuses in here? Just use a shallower taper! No probs with a 1/64" depth :roll: :roll:

Sorry John - "tail stock" chuck. Here's some pictures. I just cut a disc of a laburnum bough for the plug - it has the curious effect on the 'inside' photo of appearing to be a tunnel - a 'black hole'. The bowl is 9 " in diameter from maple rescued from a firewood pile - a certain amount of flaming I think I would describe it as. I didn't put a finish on the inside before the photos to reduce glare.

One problem is that the wood wasn't as dry as I thought it was and has moved just enough to give me a headache tidying up the inside of the foot.

Rob

 

[OldWood]

At least it didn't hit me !

 

[gus3049]

I think you might leave it a fraction thicker next time (hammer)

 

[Jonzjob]

Rob, you broke that nice bowl :shock: :shock: :shock:

Why does it need to be thicker Gordon :? :?

 

[gus3049]

Rob, you broke that nice bowl :shock: :shock: :shock:

Why does it need to be thicker Gordon :? :?

I thought maybe it wouldn't have exploded but looking again, it does look adequate. Why did it break?

 

[OldWood]

It broke because I put it on a set of button jaws to clean up the bottom of the plug - it was proud and had been made on a glue chuck so was 'gluey'. Cutting something flat like this on the face is an area I'm not confident in - had several catches in the past, so I decided to scrape it gently. And it caught again. Luckily it went away from me !!

To a certain extent Gus is right as the bottom bulge of the shape is a bit thin - 4 to 5 mm - though that wasn't the problem. That was my lack of skill sadly.

Assistance needed on how I should have done it please.

I was so pleased with the effect of the laburnum inset that I think I will do that again as an inset feature and not a repair !

Ahh well, c'est la vie. I at least got the confidence to turn larger bowls out of it, and some photos as a memory !

Rob

 

[gus3049]

Not sure why it should happen unless you had overtightened the jaws and put the bowl under too much tension. Looking at the shape of the bowl this seems a possibility. 4 to 5mm seems quite adequate to me, my yew bowl with the walnut 'accent' is 2 or 3mm at the bottom.

I use a cutter with a metal cutting profile for both roughing and fine cuts. Used gently it puts very little strain on the wood. Perhaps the fact that the plug was sticky didn't help but if the tool is sharp enough, it should cut through anything.

I don't have a set of Cole jaws and just use a disk of MDF with concentric rings cut in it and bring the tailstock up to support it. If I don't want a dimple in the bottom of the bowl and there is no thickness to remove one, I have a wooden cover for the revolving centre. Clearly, with a plug in, you have to be very gentle indeed but it might be good practice