Bowl Gouge sharpening

[Lightweeder]

I'm still trying to get decent edges on my tools and have had another go with my Tru-Grind. I can sharpen my spindle gouges by hand :? but I'm a bit in awe of the bowl gouge. I've got a passable edge on it, but it's quite vicious and catchy. I'm sweeping the wings back a bit more each time, and it's helping, but if I keep going, I'll have a similar profile to my spindle gouges. What is the preferred approach to the wings, please.

 

[CHJ]

LW, I assume your bowl gouge has an end on profile somewhat similar to this, with a deep flute.

Where are you on the shape of the wings compared with the angles shown?

This it typical of mine:

 

[Lightweeder]

Mine's looking like the 35 or 45 degree ones Chas - yours is massively swept back, compared to mine. I remember watching a demo by Andrew Hall, the hat man, and his was swept back like yours. So, are using a 75 degree angle ? Is it easy enough to have the wings swept back and still manage a rounded nose at that angle ?

 

[CHJ]

That one is 55 nose angle LW. My normal one (below) is 45, my other 'pick up' favorite for the bottom of bowls is 55.

The shape of the nose is down to how long you dwell on any particular spot, if it's getting too pointed then dwell longer on the front not the sides.

It is very easy to spend too long dwelling on the sides (as a natural result of the mechanics of the jig swing) and this results in breaking into the bottom of the flute.

This is my work horse:

I am still struggling to use this grind on dry wood in push mode using the full benefit of the long wing (best finish) and need a lot more practice OK in green. It grabs (digs) with the slightest inattention to posture etc.

I have one ground to Ellsworth, and this is even harder for me on hard dry wood. It gets used as and when I can get the confidence.

 

[wizer]

It all sounds so simple when you read it. But translating it in the workshop is hard. I have found that, like with most things in life, trial and error is the name of the game. You might waste a gouge finding your favourite setup. but at least you'd have found it. It's either that or keep your eye out for some cheap 2nd hand gouges so you can try a couple\few setups at the same time. That's what I'm doing at the moment and I'm surprised what a difference all the different setups can provide.

I see pro turners using just two gouges to turn a bowl. But personally I'm finding three or four useful. My new 25mm Straight Bowl Gouge is great fun! :shock: :lol:

 

[DaveL]

My new 25mm Straight Bowl Gouge is great fun! :shock: :lol:

And I thought the 1/2" one I have just picked up was on the chunky side. :shock:

 

[wizer]

it's a bloody beast Dave. But the perfect tool for finishing the bottom of large bowls. But if you don't take care, it will eat a large chunk of the bottom :shock:

I got it from Allen and he has bigger ones :shock: :shock:

 

[devonwoody]

Wizer, please pack in a bowl gouge with your anticipated visit. :wink:

 

[Lightweeder]

Chas - thanks. Your 'work horse' grind looks like the one that's causing me the problems, though my wings maybe can come down a bit. It's snatching at everything. I'm in the workshop this afternoon, and will aim at your swept back version. I'm not using this edge for hollowing bowls, it's more for the outside and 'truing up'. I've managed all this time without a bowl gouge, but it would be nice to get it right. As Wizer says, it might cost me most of the gouge, but it'll be worth it. Thanks people.

 

[CHJ]

LW, you might want to lower the top edge a bit from the sample above:

Like this:

That one is getting a little high, probably why it is grabbing on me.

But that edge must be Convex never Concave.

 

[Lightweeder]

Yes, I think wings need to come down a bit. They must be a fraction higher than the tip. I'll let you know how I get on, if I manage the swept back wings :shock:

 

[Lightweeder]

Well, 'result' 8) Not as deep a bevel as Chas's but deep for me, and it certainly shifts wood :shock: :shock:



I've got the co-ordinates for the future.

I've also been experimenting with a 3/8 spindle gouge, ground like a mini roughing out gouge. Is this something you all do ? It's proving very useful.

 

[CHJ]

Well done LW, when you get a form that works for you it brings such a pleasure to the proceedings.

I do have a straight ground shallow (spindle) gouge, I used to use it in the straight boring mode, now I tend to use a stiff straight scraper for that.

Tool profile and bevel grind I think is irrelevant if the tool and your method of approach works safely for you.

 

[Lightweeder]

Chas, thanks. I appreciate your time and patience.

 

[CHJ]

Chas, thanks. I appreciate your time and patience.

No problem LW, only glad the exchange got the results for you, not easy at long distance when there is so much room for mis-communication of intent.

Just watch the pattern you now have and make sure the almost straight top edge does not go concave.
Don't loose your templates of jig angles and stone to pivot point distance if it's variable in your setup.

You have mastered the key skill, tool profile is down to the person handling the tool and their appreciation of the mechanical attributes involved.
No matter what jig you use or how expensive and shinny it is if you can't get to grips with the mechanics of form generation then poor profiles will result.


I sincerely believe there is no such thing as a perfect profile to suit everybody, just some which provide the most common denominator for starters.

Lathe centre height, tool rest height and hand/arm differences all influence how a particular bevel approaches the wood.

 

[Lightweeder]

No problem LW, only glad the exchange got the results for you, not easy at long distance when there is so much room for mis-communication of intent.

I think it worked perfectly Chas. I couldn't keep going without this forum :wink:

 

[robo hippy]

I would guess that your catches are coming from how you present the cutting edge to the wood and not from the tool profile. In Chas' picture where he shows the gouge wing profile, the part of the wing that is inked in/high lighted , if used on the inside of the bowl is almost guaranteed to catch. I always roll the flutes away from the cut, so rather than being straight up and down, the gouge is more on its side. Does that make any sense?

robo hippy

 

[CHJ]

.....I always roll the flutes away from the cut, so rather than being straight up and down, the gouge is more on its side. Does that make any sense?

robo hippy

Spot on IME, precisely how I present them in push mode, nose bevel rubbing not side, can't yet use them in pull mode on dry wood with any confidence even with flatter top edge profile than the inked one.

 

[Lightweeder]

Robo - I was just truing up at the time, and working 'round the outside of my workpiece. You'll see from my pic' that I've taken the sides down, more in the way of Chas's, and it's 100% better. I take your point though, and thanks.

 

[duncanh]

Would it be useful if I came round some time to see what's happening and give some advice? I may have some free time next week.
And is any of that oak still lying around?