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What's the most difficult KD hardwood to turn a bowl?

Odie

Odie

Panning for Montana gold, with Betsy, the mule!
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I've recently turned some kiln dried purpleheart that I'm thinking is the most difficult wood to get a clean cut across the end grain. A close second might be marblewood.

What's been difficult for you?

1291 Marblewood (5).JPG 1429 purple heart (5).JPG
 
Turned a piece of Black Palm a couple months ago......tearout on the end grain was so pronounced, that I didn't bother to finish it. The tearout was doable when roughed out, but much more dramatic after the MC was stabilized. Won't ever buy any more of that. I suppose I could have finished it, but I felt the general look of Black Palm didn't warrant the effort that would have been necessary to complete it. I have one more roughed piece of Black Palm that will probably sit on the shelf for next to eternity! 😀

I still will buy some nice pieces of Purpleheart and Marblewood, when I run across a good deal. I wouldn't bother with either of them ever again, if it wasn't for they being such truly unique and interesting woods.....
 
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I don't think that it makes any difference in turning characteristics whether the wood was kiln dried or air dried if we're talking about turning wood that is thoroughly dry.

Fir, cedar and zebra wood tend to splinter easily. Spalting wood sometimes is difficult to to get a clean cut in end grain because of tear out. Wood that has a high mineral content can be impossible to turn because it dulls tools so quickly. Cocobolo is so hard that it dulls tools and turning is a slow process, but the wood cuts cleanly. I don't know how I would compare degree of difficulty among these various unrelated problems.
 
Bill Boehme said:
I don't think that it makes any difference in turning characteristics whether the wood was kiln dried or air dried if we're talking about turning wood that is thoroughly dry.
Click to expand...

Actually, it does, Bill.......some KD woods are actually lower in MC, than air dried. I have gotten KD woods that were the other way around, as well. I've gotten some KD blocks that registered 14%, that (after roughing) still lost weight in my own shop environment. I've also gotten some KD woods in the past that registered as low as 6% MC......(That's the lowest I've ever seen.) I wonder if this 6% wood will actually increase in MC over time......? I'll bet it does, but haven't ever done any tests to confirmed that. I guess this all boils down to just who's kiln we're talking about, and how it was stored afterwards.

However, for the purposes of this discussion, I'd like to hear what experiences anyone has to offer about either KD, or air dried woods. Specifically, my intent is to discuss the turning characteristics of dry wood when finish turned to completion.....either KD, or air dried.

Good point about spalted woods. I've tossed out plenty of it that has been impossible to have a clean enough cut for sanding purposes.

ko
 
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I agree on spalted, worst was a piece of Virginia soft maple salted.....seems that the area turned a yellow with brown area.....my sister loved the shape for her sewing odds
 
I have got some rough outs drier than the relative humidity by using a microwave oven. I use the weight method of keeping track of the moisture content and I have had bowl blanks gain weight for a day or two after drying. I have moisture meters one is pin type and the other is a proximity gauge and they are kind of like an educated guess. Pretty good after you get to know the readings to expect. I sometimes see bowls that are 10 to 20 percentage points different depending where you check the bowl. End grain is always the lowest reading and the bottom tenon is the highest. I usually get the cut edge bowls a little drier than a natural edge bowl. I don't mind the NE bowls warping a bit but I do expect them set level and not wobble.
 
Huge differences in properly dried woods and methods. I did flat work for some years, and working air dried, solar kiln dried, or vacuum kiln dried woods was a pleasure. They cut and work almost like green wood. Kill dried wood, after getting used to the other woods, is a pain, and I never ran into any that didn't have 'internal stresses' as in it would cup, bow, and just plain twang when you would rip a board, or saw a plank for book matched sets. Run an air dried board through the table saw and you get shavings. Run a kill dried board through the saw, and you get dust. Same thing with running through the planer or jointer.

Odie, you can get the palm to cut fairly well, but it has to be an end grain turning, not side grain like normal bowls. I had a friend give me a piece of coconut palm once. I still haven't forgiven him....

robo hippy
 
odie said:
Actually, it does, Bill.......some KD woods are actually lower in MC, than air dried. I have gotten KD woods that were the other way around, as well. I've gotten some KD blocks that registered 14%, that (after roughing) still lost weight in my own shop environment. I've also gotten some KD woods in the past that registered as low as 6% MC......(That's the lowest I've ever seen.) I wonder if this 6% wood will actually increase in MC over time......? I'll bet it does, but haven't ever done any tests to confirmed that. I guess this all boils down to just who's kiln we're talking about, and how it was stored afterwards.
Click to expand...

The main reason for my comment is that I don't think that I have ever run across turning blocks that were kiln dried. When I did flat woodworking I usually bought my wood from Hardwood Lumber Company of Dallas. I usually bought rough edged lumber that wasn't planed or just skip planed on one side. Much of the less commonly used hardwoods were air dried and it was difficult to find anything thicker than 8/4 KD hardwood. Turning blanks are typically thicker than what the lumber dealer sold and it is almost always waxed which tells me that it wasn't kiln dried.

But, my thought is that the difference between kiln drying and air drying might account for a small difference in stability during or after turning, but I can't imagine that it will have any difference on some of the fundamental characteristics such as tendency to splinter. I've always heard that KD wood will have a slightly lower moisture content than air dried wood, but since I don't know whether I have actually turned any KD wood, I can't offer any personal experience that there is an observable difference.
 
Bill Boehme said:
The main reason for my comment is that I don't think that I have ever run across turning blocks that were kiln dried. When I did flat woodworking I usually bought my wood from Hardwood Lumber Company of Dallas. I usually bought rough edged lumber that wasn't planed or just skip planed on one side. Much of the less commonly used hardwoods were air dried and it was difficult to find anything thicker than 8/4 KD hardwood. Turning blanks are typically thicker than what the lumber dealer sold and it is almost always waxed which tells me that it wasn't kiln dried.

But, my thought is that the difference between kiln drying and air drying might account for a small difference in stability during or after turning, but I can't imagine that it will have any difference on some of the fundamental characteristics such as tendency to splinter. I've always heard that KD wood will have a slightly lower moisture content than air dried wood, but since I don't know whether I have actually turned any KD wood, I can't offer any personal experience that there is an observable difference.
Click to expand...

You could very well be correct that the difference between KD and air dried isn't going to be drastic insomuch as how it responds to the tool. I suspect there will be a difference, but how would you know for sure......other than drawing our own intuitive conclusions based on our own personal observations? Most of us will agree that very wet wood will turn differently than the same wood that has the MC stabilized. I guess, in order to draw a definitive answer to the question, two blocks of wood, of the same species (or, even from the same tree).....one KD, and the other air dried, could be mounted and turned. That would give observable differences that could be conclusive.......well, in theory, anyway! 🙂 I've never really cared that much to know for sure, but it does seem to me that even small differences in MC can become the transitional point between a good tool surface, and a surface that requires more sanding......all other things being equal, of course.
 
I prefer dried wood for platters and boxes. While dried wood may be thick enough for shallow bowls i prefer green wood for bowls and dry the turned bowl. Dry Wood for hemispherical bowls 10"+ just isn't available.

Cutting spindle orientation works well on dry wood so boxes cut cleanly.
Shallow bowls and platters are oriented face grain making it difficult or impossible to cut cross grain which leaves clean surfaces in bowls with the cutting tools.
cutting into the end grain often makes tear out. Light cuts and shear scraping are needed for a clean surface.

Palm can be turned but it is not wood. Sharp tools, light cuts, dense palm blank, carful attention to cutting the fibers so that they are supported will minimize the tear out. Palm is very much like a bundle of broom straws.
 
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If you run a hand plane over some KD wood and some air dried wood, there is a huge difference in how they cut. Any KD wood will come out of a kiln at a moisture content lower than what is generally achieved through air drying unless you are in Palm Springs or some other dry place. As it sits out in the open, it will the MC levels will go up until it is at 'equilibrium', then both KD and AD will have the same moisture levels. It is next to impossible to dry anything evenly at thicknesses over 8/4 and get any kind of equilibrium. It can be done, but really difficult.

robo hippy
 
Regarding air dried versus KD, years ago I had automatic variety lathe very similar to one in the YouTube video link. The manufacturer specified air dried birch as the ideal turning wood. Being in the Pacific Northwest you take what the local suppliers have, which is not air dried birch. So I had to compromise on air dried hard maple although I was never sure air dried or KD maple made much difference.

Note the cycle time per part, they can run much faster if the part doesn't have so much detail. Making the cutters is quite an art.


https://www.google.com/url?sa=t&rct...lJsbgw&usg=AFQjCNHdDA8SwmHPE4YKh1iptwdZaY6Bcw
 
A co-worker gave me some tigerwood today, this wood is very dense and hard.
He broke a number of drill bits drilling holes in this wood, we will see what it does on the lathe.
 
Several different species are sold as tigerwood. Here is a link from Wagner Meters (maker of wood moisture meters) that gives information on Lovoa trichilioides which I presume is the real tigerwood. Even Gonçalo Alves, the Brazilian hardwood is also sometime marketed as Tigerwood. To add to the confusion, there are at least a couple different species that are often sold as Gonçalo Alves.
 
When you start down the path of researching "wood" tree species the list grows quickly.
There are thousands of species of trees and many of the common tree species have many
types included in their family. Hard enough to keep track of the domestic species in this country
when you add the rest of the world to the list you get around 100,000 species.
 
Okay, lets start with the A's...

🙄🙂
 
Clifton C said:
I like Bradford Pear, but do I have to wait till we get to the "P's"?
Click to expand...

By all means P now if you need to. I'm sure others have been in your position, Clifton. </deadpan>
 
odie said:
I've recently turned some kiln dried purpleheart that I'm thinking is the most difficult wood to get a clean cut across the end grain. A close second might be marblewood.

What's been difficult for you?
Click to expand...

Can't match your experience with purpleheart, I do recall dry Madrone and dry chestnut were extremely difficult (but with novice status, that doesn't mean much). Just want to throw out there, I overheard a couple of bowl turners discussing how much lathering up a difficult dry bowl blank with soap and water makes the cutting much easier. Haven't tried it m'self.
 
Mimosa. Stringy and blunts tools quickly. Pretty dense too.
 
Turned some of the tigerwood today and it was not as difficult to turn as I imagined.
I have turned hickory wood that was much harder then the tigerwood.
 
Jamie Straw said:
Can't match your experience with purpleheart, I do recall dry Madrone and dry chestnut were extremely difficult (but with novice status, that doesn't mean much). Just want to throw out there, I overheard a couple of bowl turners discussing how much lathering up a difficult dry bowl blank with soap and water makes the cutting much easier. Haven't tried it m'self.
Click to expand...

The purpleheart bowl that inspired this thread was completed yesterday (except for the foot), I had such a difficult time with the last one, that I did a fairly easy shape that lent itself to easy sanding.
IMG_2457.JPG
Today, I'm working on a new problem bowl......black and white ebony. I have turned a couple Gabon ebony bowls in the past, but l haven't ever turned black and white ebony. It's not similar at all.....!

This piece of wood was very expensive, and I don't want to take any chances experimenting with unknown techniques. It wasn't all that difficult to get a reasonable cut when it was wet. Now that it's stabilized, it's being very difficult to get a decent cut. I'm a little hesitant to use soap and water on it, because I'm not sure how to remove soap, once it is introduced into the wood. Maybe you could ask your turning friends just how they deal with this.......?
I worked on this again this afternoon, and came up with a better surface than you see here, but still not as good as I'd like prior to sanding.

Unfortunately, this black and white ebony roughout developed a severe crack during seasoning, and will need an epoxy repair. I'm not sure I can sell this one, because the split is pretty obvious (not shown in this photo).......darn it! 🙁 Even though there is a serious flaw, I want to finish this one as best as I can......for the experience of it. It was such a disappointment to see the split. :mad:

I was warned by the seller of this block that black and white ebony is known for splitting badly......anyone want to comment on that? Has anyone else made a bowl out of black and white ebony before?
IMG_2458.JPG
ko
 
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Odie,
Your purpleheart bowl turned out great! I like your detail on the rim of the bowls.
How do your apply such fine lines on the rims? I would assume a sharp tool and delicate precise cuts?
 
Mike Johnson said:
Odie,
Your purpleheart bowl turned out great! I like your detail on the rim of the bowls.
How do your apply such fine lines on the rims? I would assume a sharp tool and delicate precise cuts?
Click to expand...

Good morning........🙂

Thanks, Mike.......Yes, "sharp tool and delicate precise cuts" is the name of the game for cleanly cut detail grooves. I do mine with a spear point scraper, which can be made out of any standard scraper ground to a point. The angle of the point is acute.....about 20-25°, or so. I haven't been able to do a raised bur without bending the very tip of the point over, so I use a ground bur that is refreshed every time I use it, so that it will cut as clean as possible. A raised bur would work better, but if the very tip of the point is bent over ever so slightly, the results won't be as good. When cutting the detail groove, it's plunged in straight with steady even pressure, very close to exact centerline of the workpiece. (Never above centerline) Detail grooves are done at around 1000rpm, but each lathe is probably different, because it's necessary to adjust rpm for the very least amount of situational vibration, as possible. The faster the rpm, the cleaner the cut.......with the caveat that the faster the rpm, the more it will exacerbate any vibrations you do have.......damned if you do, and damned if you don't sort of thing.....so, it does take a little knack, and familiarity with your own lathe's tendency to vibrate. (And developing your ability to assess the clues, and adjust the speed accordingly.) It's not a quick plunge, but a very slow thrust with steady even pressure. It's such a slow cut, that it only creates a very fine dust. It does take a little practice to get the hang of it, but once the light bulb turns on in your secondary consciousness, it's very satisfying to create a detail groove without any tearout whatsoever.

ko
 
many years ago I used to buy air dried wych elm from an old fashioned sawmill and that was very difficult to achieve a clean cut on.

recently I turned a box with some port orford cedar and although the swirly grain was amazing, I really struggled to get a clean cut.
here is a picture of the boxDSC_0985.JPG
 
IMG_2459.JPG

Update on the B&W Ebony bowl........Well, thank heavens for the raised bur scraper. I was able to get a clean enough surface to start sanding at 240 grit. I haven't taken it to a finer grit yet, because the bowl now has an epoxy fill for the crack. Hopefully, it won't stick out like a sore thumb, as I added some of the sanding dust to the epoxy while mixing.

BTW: I was wearing my modified women's softball fielder's mask while I turned this one. I wasn't sure it wouldn't explode into pieces while I turned! 😱
IMG_0627.JPG
 
Had some free time on the lathe this morning and tested a few tigerwood pieces.
Made a simple bangle, napkin ring, coaster, and ring.
The wood was nice and solid for making hollow ring type items.
My next item might be a spinning top, the heavy dense hard wood will work nice for a top.
The wood sands and polishes like a hard maple.

tigerwoods.jpg
 
odie said:
View attachment 21422

Update on the B&W Ebony bowl........Well, thank heavens for the raised bur scraper. I was able to get a clean enough surface to start sanding at 240 grit. I haven't taken it to a finer grit yet, because the bowl now has an epoxy fill for the crack. Hopefully, it won't stick out like a sore thumb, as I added some of the sanding dust to the epoxy while mixing ...
Click to expand...

Looks like an opportunity to experiment with a creative rescue such as a couple pewas or some wire staples or leather lacing.

I first heard about using a pewa patch from Hawaiian woodturner Kelly Dunn and for the benefit of anybody who is not familiar with the process, here is a YouTube video.

View: https://m.youtube.com/watch?v=7srlFcsK0eQ
 
Bill Boehme said:
Looks like an opportunity to experiment with a creative rescue such as a couple pewas or some wire staples or leather lacing.

I first heard about using a pewa patch from Hawaiian woodturner Kelly Dunn and for the benefit of anybody who is not familiar with the process, here is a YouTube video.

View: https://m.youtube.com/watch?v=7srlFcsK0eQ
Click to expand...

Thanks for posting that demo, Bill.......I've seen these Pewa's before, but this was my initiation for how it is done. As for the Black and White Ebony bowl with the split, shown in this thread......well, the crack has already been filled with epoxy mixed with some sanding dust. I don't expect it will be an invisible repair. I'm hoping it won't look too bad after it's final turned completely, inside and out. As you can see, the split goes most of the height of the bowl, so turning it out wasn't really an option, from my POV. I've got my fingers crossed, but am prepared for a total loss, if that's what's in the cards for this one.

ko
 
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