Knowing when wood is punky?

[Rachel Aberle]

I had a batch of wet maple I’ve been working with. As a new turner, I thought my skills has slipped. Last week I couldn’t get a smooth cut at all. I kept sharpening the gouge, made sure bevel support and it would be okay for a spell then create bounce on the wood and it took long to get rid of it. So once I turned the wood around to work on the inside, I found that it was punky on the inside, some rotted areas. This may also explain while the piece was round, it shook the lathe when trying to speed up, I couldn’t up the speed much at all.

Today I decided to try turning some Chinese Elm I have and what a difference. My cuts were like butter.

Is there a skill to learn earlier on that wood is crap on the inside. Should I have assumed the troubles I had on the outside of the maple were a sign of poor insides? Note: newer turner here so was thinking it was me at first.

 

[John Walls]

I get alot of tear-out on punky wood myself. While I've ... almost... got decent technique down to eliminate tear-out of solid wood, punky, my favorite, smooth cuts still elude me. I get punky maple and box-elder, most times I can tell from the outside or chainsawed ends if/how punky it is. If I can't put a finger through it, I turn it then sand alot. I do every so often turn a piece that is solid on the outside and punky on inside. I'm not able to detect until I cut in if it's punky or not, well, sometimes I can tell by the weight, solid wood is much heavier than wood with soft/punky insides. So as a rookie myself, I would vote on weight as a good clue.

 

[Rachel Aberle]

I get alot of tear-out on punky wood myself. While I've ... almost... got decent technique down to eliminate tear-out of solid wood, punky, my favorite, smooth cuts still elude me. I get punky maple and box-elder, most times I can tell from the outside or chainsawed ends if/how punky it is. If I can't put a finger through it, I turn it then sand alot. I do every so often turn a piece that is solid on the outside and punky on inside. I'm not able to detect until I cut in if it's punky or not, well, sometimes I can tell by the weight, solid wood is much heavier than wood with soft/punky insides. So as a rookie myself, I would vote on weight as a good clue.

Good points. Interesting that it wouldn’t stabilize at all to turn up the lathe while being round. So different from the Chinese elm I turned, was able to turn up lathe easily without the vibration.

 

[Richard Coers]

Wet maple isn't much of a description of the species. If it's silver maple, it can tear out easily on the end grain. Wet hard maple turns as nice as turning a potato. Chisel bounce is an operator error, not a result of wood species. Usually you can see by the color that there is some rot. It's unusual to see perfect color on the outside and then an inch away it is completely rotten.

 

[Rachel Aberle]

Wet maple isn't much of a description of the species. If it's silver maple, it can tear out easily on the end grain. Wet hard maple turns as nice as turning a potato. Chisel bounce is an operator error, not a result of wood species. Usually you can see by the color that there is some rot. It's unusual to see perfect color on the outside and then an inch away it is completely rotten.

I wish I knew exact beyond maple.

 

[Don Wattenhofer]

sure bevel support and it would be okay for a spell then create bounce on the wood

The hard / soft of partially punky wood is an indicator that it is punky and it will cause the bounce with too much "bevel support".

 

[Rachel Aberle]

The hard / soft of partially punky wood is an indicator that it is punky and it will cause the bounce with too much "bevel support".

What would be considered too much?

 

[hockenbery]

T

What would be considered too much?

I like for the bevel to float over the part just cut.
Too much is when I can feel a slight downward pressure from the bevel dragging over the wood.
I need a loose grip on the tool to be able to feel it.

When I put the bevel on the wood to pick up the cut I should be able to slide the tool back a forth on the bevel feeling contact but no resistance. Resistance is from too much pressure against the wood of from sap.

If resin builds up on the bevel this creates bevel drag.
With some woods I sharpen a sharp tool to clean the bevel.

 

[robo hippy]

Well, worst piece I ever turned was a side grain piece of coconut palm. Never again! Nothing could get it to cut cleanly. Turned a shop dried for many years piece of Koa. Not the hardest wood I ever turned, but left nasty tear out. I was able to tame it by misting it with water and very gently turning away the wet stuff. Maple has a tendency to be difficult to turn cleanly, just the structure of the wood. Some times the tear out can be tamed by using a 600 grit wheel for the gouge edge for your finish cuts. I have better luck with the wheel than I do with a hand hone. A high shear/slicing angle is good for a smoother finish cut, as in drop handle and cut with the wing on the outside, and BOB type tool on the inside since you can't drop the handle very well on the inside of the bowl. If the wood is rotten, as in you are tearing out chunks rather than getting cuts and shavings, I don't even try, though some like the challenge of taming the nastiest pieces of wood they can find. After 25+ years of bowl turning, I am getting better at predicting what the piece of wood will require for taming, or if I should just burn it. I do have a wood stove....

robo hippy

 

[Odie]

Since I buy wood from photos online, I've found the best way to judge punkiness, is to take a close look at the end grain. Some provider's saws are sharper than others, and some use table saws, band saws, etc., but if I see any major tearout there, I pass.

Still, it's difficult to know for sure, and I still get burned occasionally, but I still take my chances now and then.

I can say for sure that a well turned piece of spalted wood will have plenty of admirers.....and will sell.

-----odie-----

 

[Don Wattenhofer]

What would be considered too much?

For me not more than about 15% in maple, but for something like birch about 1% or less.

 

[Don Wattenhofer]

Well, worst piece I ever turned was a side grain piece of coconut palm.

I think the subject is woodturning not grass turning.

 

[Mark Jundanian]

Interesting that it wouldn’t stabilize at all to turn up the lathe while being round.

The punky areas are less dense than the good wood. So even round it may have been out of balance.

 

[robo hippy]

Grass turning would be bamboo.... Not sure what palm is..... You can do spindles and end grain pieces, and they to come out much cleaner than side grain....

robo hippy

 

[Don Wattenhofer]

Grass turning would be bamboo.... Not sure what palm is..... You can do spindles and end grain pieces, and they to come out much cleaner than side grain....

robo hippy

I had heard that it isn't really wood and any samples of it I have seen sure didn't look like wood, but then it doesn't look like grass either. I tried looking up on the internet but did not find anything to define it as wood or something else.
So maybe I should have called it "Big Tropical Plant Turning" or just not said anything.

 

[hockenbery]

Pa

Grass turning would be bamboo.... Not sure what palm is..... You can do spindles and end grain pieces, and they to come out much cleaner than side grain....

robo hippy

Palms are a classified a grass too.

Palms have long fibers. When they are densely packed it turns fairly well because the fiber support the ones being cut
When loosely pack it doesn’t turn well because each fiber without support bends and tears rather than cutting.

 

[Rachel Aberle]

Well, worst piece I ever turned was a side grain piece of coconut palm. Never again! Nothing could get it to cut cleanly. Turned a shop dried for many years piece of Koa. Not the hardest wood I ever turned, but left nasty tear out. I was able to tame it by misting it with water and very gently turning away the wet stuff. Maple has a tendency to be difficult to turn cleanly, just the structure of the wood. Some times the tear out can be tamed by using a 600 grit wheel for the gouge edge for your finish cuts. I have better luck with the wheel than I do with a hand hone. A high shear/slicing angle is good for a smoother finish cut, as in drop handle and cut with the wing on the outside, and BOB type tool on the inside since you can't drop the handle very well on the inside of the bowl. If the wood is rotten, as in you are tearing out chunks rather than getting cuts and shavings, I don't even try, though some like the challenge of taming the nastiest pieces of wood they can find. After 25+ years of bowl turning, I am getting better at predicting what the piece of wood will require for taming, or if I should just burn it. I do have a wood stove....

robo hippy

We have a fire pit. . Being newer I’ve been okay with Ash, walnut and elm so far but walnut wasn’t easy at all. Probably this batch of wood but I also had a dried blank I had purchased with not much luck. A change in technique to work with it as you’ve mentioned.

 

[Leo Van Der Loo]

I had a batch of wet maple I’ve been working with. As a new turner, I thought my skills has slipped. Last week I couldn’t get a smooth cut at all. I kept sharpening the gouge, made sure bevel support and it would be okay for a spell then create bounce on the wood and it took long to get rid of it. So once I turned the wood around to work on the inside, I found that it was punky on the inside, some rotted areas. This may also explain while the piece was round, it shook the lathe when trying to speed up, I couldn’t up the speed much at all.

Today I decided to try turning some Chinese Elm I have and what a difference. My cuts were like butter.

Is there a skill to learn earlier on that wood is crap on the inside. Should I have assumed the troubles I had on the outside of the maple were a sign of poor insides? Note: newer turner here so was thinking it was me at first.

Yes there is a lot to be learned when going to turn wood, also the tree species, like there does not grow a Chinese tree in Wisconsin, but lots of Siberian Elm and still some American Elm probably

For punky wood,
It does normally show if wood is in bad shape, color will show it, lines and spots, also on the endgrain of the log, your nail will be able to mark the soft punky wood.

Sometimes you can be lucky and find spalted wood, like Maple or Birch and Sycamore that is spalted and still pretty solid, but you have to learn to recognize this, the same with tree species.



Like the Chinese bark you can see below.
Siberian elm will grow all over in the cold north like Siberia, it has a a mature tree very rough bark with deep fissures, here is one growing behind my place in London Ontario.




The Siberian elm and Chinese Elm

 

[Rachel Aberle]

Yes there is a lot to be learned when going to turn wood, also the tree species, like there does not grow a Chinese tree in Wisconsin, but lots of Siberian Elm and still some American Elm probably

For punky wood,
It does normally show if wood is in bad shape, color will show it, lines and spots, also on the endgrain of the log, your nail will be able to mark the soft punky wood.

Sometimes you can be lucky and find spalted wood, like Maple or Birch and Sycamore that is spalted and still pretty solid, but you have to learn to recognize this, the same with tree species.

View attachment 43766

Like the Chinese bark you can see below.View attachment 43761
Siberian elm will grow all over in the cold north like Siberia, it has a a mature tree very rough bark with deep fissures, here is one growing behind my place in London Ontario.

View attachment 43762


The Siberian elm and Chinese Elm
View attachment 43765

Good catch. The sawmill place said Chinese elm but I bet it’s Siberian. Lots and lots to learn. I wish there was a good course on identifying this all for a lay person.

 

[Tim Tucker]

Rachel- the phrase “good catch” is one that gives me shivers….

 

[Rachel Aberle]

Rachel- the phrase “good catch” is one that gives me shivers….

Oops sorry

 

[Tim Tucker]

Only kidding you….

 

[Don Wattenhofer]

Sometimes you can be lucky and find spalted wood, like Maple or Birch and Sycamore that is spalted and still pretty solid

The white birch we have here in central MN (about 200 miles south of Rainy lake) in my experience when it gets spalted it is also punky within a very short window of time.

 

[robo hippy]

Leo, years ago, flew into Winnipeg for a fishing trip out of Kenora. Driving from the airport to the hotel where I was meeting up with family, the cab driver mentioned that Winnipeg had the highest per capita # of American Elm trees in North America. There were a bunch of them after I started looking.

robo hippy

 

[Leo Van Der Loo]

The white birch we have here in central MN (about 200 miles south of Rainy lake) in my experience when it gets spalted it is also punky within a very short window of time.

Yes Don, the Birch has a short time between fresh and rotten wood, probably half a year if winter is included in that time.

I got a bunch of Birch from a bundle that was sitting as a drain under the new driveway to my son's place he was building (1/2 mile long) done in the summer and I had a look the next year, it was spalted but not rotten yet, I cut all the ends I could use off, peeled the bark off (very important as the waterproof bark will not let the wood dry) and turned a bunch to boxes and some Birdhouse ornaments, still have a bucket with those sticks in it to be used in my next life I think .

 

[Leo Van Der Loo]

Leo, years ago, flew into Winnipeg for a fishing trip out of Kenora. Driving from the airport to the hotel where I was meeting up with family, the cab driver mentioned that Winnipeg had the highest per capita # of American Elm trees in North America. There were a bunch of them after I started looking.

robo hippy

I have been several times in Winnipeg, and yes they still have mature White Elm AKA American Elm, though the ones I have seen (City Park) were not as large as the ones that grew faster south, like I've seen in S. Ontario.

We still have a few White Elm trees here in town, but they are slowly dying off, one at a time.

This is the White Elm bark from the Winnipeg Elms.

 

[Tom Lucas]

I tried to save some beautiful spalted apple. I learned a lesson from it: if it's punky best to just burn it. I wasted several hours, pluse about a pint of cactus juice trying to save some of it. What a waste of time and money!

 

[Emiliano Achaval]

T
I like for the bevel to float over the part just cut.
Too much is when I can feel a slight downward pressure from the bevel dragging over the wood.
I need a loose grip on the tool to be able to feel it.

When I put the bevel on the wood to pick up the cut I should be able to slide the tool back a forth on the bevel feeling contact but no resistance. Resistance is from too much pressure against the wood of from sap.

If resin builds up on the bevel this creates bevel drag.
With some woods I sharpen a sharp tool to clean the bevel.

I hate to clog up with CBN wheels with sap. I keep large 3M pads that I buy at the welding supply store to clean up the gouges before I sharpen them on my wheels. I stopped even using the black sharpie because I could see the wheel picking up the black.

 

[Emiliano Achaval]

In Hawaii, we let the Cook Pine spalt for about 4 months. We water it every day. I have a sprinkler on a timer so I don't have to do it manually. Once you get the nice spalting, it can go from nice to punky, then rotten all within a short few weeks. I do not bring in large loads anymore because I can't get to it before it turns punky.

 

[Leo Van Der Loo]

I tried to save some beautiful spalted apple. I learned a lesson from it: if it's punky best to just burn it. I wasted several hours, pluse about a pint of cactus juice trying to save some of it. What a waste of time and money!

Tom you got to know before you start if the wood is still usable, also wood that is wet keeps on rotting, so turn it and dry it.

I've turned lots of Apple wood, some of it spalted, it can be very nice, and probably also a challenge to cut clean.

I have 3 rough turned Spalted Applewood bowls in the next 2 pictures, they were just about getting too soft, but I was still able to rough turn them, rough turned 2008.





Got a picture of one of these finished about half a year ago, PTO (Polymerized Tung Oil) as the finish on it (it is the lower right one of the above picture).

 

[Tom Lucas]

Tom you got to know before you start if the wood is still usable, also wood that is wet keeps on rotting, so turn it and dry it.

I've turned lots of Apple wood, some of it spalted, it can be very nice, and probably also a challenge to cut clean.

I have 3 rough turned Spalted Applewood bowls in the next 2 pictures, they were just about getting too soft, but I was still able to rough turn them, rough turned 2008.



Beautiful pieces. Mine was too far gone and I didn't know better. I have some fresh cut drying. Expect it will spalt where it is (dark and humid). Will try to catch it when it's just right.