Differences cutting within wood??

[RegisG]

I'm still wading into turning pen sized pieces of wood, learning/practicing.
I had glued up a nicely grained piece and this morning started turning it. As I moved across, it was like my skew went completely dull. I touched it up on grinder but, on this piece of wood (unknown type) there was area very easy to cut. And then where the nice grain is, cutting was VERY slow. More scraping than cutting. Is this common or is there something that I "should" know?
Here are couple pictures of the wood I'm talking about.

Tips appreciated,
Regis

 

[Skie_M]

Where you went down past the bushing ... most likely you hit sapwood which is right under the bark ... also known as "pith". It could also just be rotted wood... it's MUCH softer than the rest of the tree.

Where the cutting was more difficult, you were cutting in very dense grain. There appears to be a knot there that you were cutting into. The grain patterning around knots is quite lovely, and much denser than normal, as the wood around these locations gets compressed by the growth of the tree.


Sharp tools, the highest speed you are comfortable using on the lathe, light passes ... keep that bevel rubbing the wood whenever you can!


The wood appears to be pine .... you may want to use a freshly sharpened bowl gouge and a sheer cutting motion.

 

[jttheclockman]

That is your basic knot in the wood. A lot more dense thus the different cutting properties. Need to adjust the approach and hang with it. Just know it is there and how it changes so that you do not ruin the blank. Could look real super when done and worth the effort. No not all woods are like that.

 

[RegisG]

Where you went down past the bushing ... most likely you hit sapwood which is right under the bark ... also known as "pith". It could also just be rotted wood... it's MUCH softer than the rest of the tree.

Where the cutting was more difficult, you were cutting in very dense grain. There appears to be a knot there that you were cutting into. The grain patterning around knots is quite lovely, and much denser than normal, as the wood around these locations gets compressed by the growth of the tree.


Sharp tools, the highest speed you are comfortable using on the lathe, light passes ... keep that bevel rubbing the wood whenever you can!


The wood appears to be pine .... you may want to use a freshly sharpened bowl gouge and a sheer cutting motion.

That really is a great grain pattern and that is I why I want to save it. Where it looks like I went below the bushing, this kit said to cut 1/8" down to the tube.
I was only turning about 2400 so I will bump up speed to little over 3000.

Because it looks so good I wish I would have saved it for a one-piece after I had more experience. Even though I am making some kits, mostly I am building skills.

I was quite surprised how drastic a difference the cutting was

Thanks,
Regis

Thanks,
Regis

 

[Skie_M]

It's all good, man ... this stuff DOES grow on trees, you know ...

 

[1080Wayne]

Where you went down past the bushing ... most likely you hit sapwood which is right under the bark ... also known as "pith". It could also just be rotted wood... it's MUCH softer than the rest of the tree.

Where the cutting was more difficult, you were cutting in very dense grain. There appears to be a knot there that you were cutting into. The grain patterning around knots is quite lovely, and much denser than normal, as the wood around these locations gets compressed by the growth of the tree.


Sharp tools, the highest speed you are comfortable using on the lathe, light passes ... keep that bevel rubbing the wood whenever you can!


The wood appears to be pine .... you may want to use a freshly sharpened bowl gouge and a sheer cutting motion.

`Pith`is the soft wood at the center of the tree or branch , generally the first years growth .

Knots are almost always harder than the surrounding wood , but the attractiveness usually makes up for the difficulty . Pine is frequently maligned for being too plain , but it`s knots are not .

 

[oldtoolsniper]

Sent from my iPad using Penturners.org mobile app

 

[RegisG]

Sent from my iPad using Penturners.org mobile app

That's great. I've heard most of those terms all my life (long time) but, other than heartwood and bark, didn't really know much else.

Thank you for the education.
Regis

 

[Skie_M]

Hmm ... I've always heard of the very soft wood layer just beneath the bark (between the sapwood and the bark) as pith, or pithy wood ... Looks like the proper term for it was the Cambium ...

 

[oldtoolsniper]

Sent from my iPad using Penturners.org mobile app

That's great. I've heard most of those terms all my life (long time) but, other than heartwood and bark, didn't really know much else.



Thank you for the education.

Regis

Well that picture depicts the perfect world. As others have said it appears as though you are dealing with a knot. That's a branch that looks just like that picture only inserted sideways. You are at the crossroads of two of those pictures combined at angles.

Makes for hard, soft, and everything in between when turning, it is also what makes for a beautiful piece of wood. On some of that stuff a chunk of 60 grit sandpaper may be the answer.

Sent from my iPad using Penturners.org mobile app

 

[leehljp]

Two items from me:

1. Many people use the skew like a scraper; it works much better when used as a skew! :biggrin: Seriously, early on some people tend to use the skew wrong. Hope that wasn't a contributor to your situation.

2. Next, a bad habit is developed that hurts in the long run when a tool is sharpened on any grinder and not honed. Honing takes the sharpness up a couple of levels with a few swipes. I may be reading people wrong, or they are skipping a step in explanations, but it is quite common to read that they sharpen on the grinder and go to turning . . . with little said about the honing. Honing may take a minute or two the first time after the grinder, and then honing can take place in a few seconds as a swipe across a leather strap or other. This honing can be repeated several times like this: hone, turn and cut some, swipe/hone a couple of time on each side, turn some, swipe, turn some etc, etc - and then grind when honing doesn't sharpen any more.

I was intrigued by your statement of "touch up" on the grinder. Generally a touch up at any given point is completed with a honing process. Chisels sharpened even on a Tormek should be honed. It REALLY helps.

 

[RegisG]

Two items from me:

1. Many people use the skew like a scraper; it works much better when used as a skew! :biggrin: Seriously, early on some people tend to use the skew wrong. Hope that wasn't a contributor to your situation.

2. Next, a bad habit is developed that hurts in the long run when a tool is sharpened on any grinder and not honed. Honing takes the sharpness up a couple of levels with a few swipes. I may be reading people wrong, or they are skipping a step in explanations, but it is quite common to read that they sharpen on the grinder and go to turning . . . with little said about the honing. Honing may take a minute or two the first time after the grinder, and then honing can take place in a few seconds as a swipe across a leather strap or other. This honing can be repeated several times like this: hone, turn and cut some, swipe/hone a couple of time on each side, turn some, swipe, turn some etc, etc - and then grind when honing doesn't sharpen any more.

I was intrigued by your statement of "touch up" on the grinder. Generally a touch up at any given point is completed with a honing process. Chisels sharpened even on a Tormek should be honed. It REALLY helps.

Your point is well taken. I know that I need to work on sharpening. I have a fine diamond wetstone and will have to try it on my skew. I even have leather strop for sharpening leather carving knife. I will work on honing as I do know that I need to improve my sharpening.

Thanks,
Regis

 

[TonyL]

I found these helpful:
https://www.youtube.com/watch?v=YFlZyGKYro4
https://www.youtube.com/watch?v=0U4Z-Rm6PjA&list=PLjRwVZZffCDRx9DdpsJQSflOwxlTR5B0m
https://www.youtube.com/watch?v=yhuEVVSkDtE&index=3&list=PLjRwVZZffCDRx9DdpsJQSflOwxlTR5B0m
https://www.youtube.com/watch?v=dNq2o2HeSVg
https://www.youtube.com/watch?v=jOvF5f1phhY