Found some downed trees today in Brooklyn

[John K Jordan]

I just had a thought. How concerned should I be regarding ambrosia? The logs with the darker heart wood seems to be ambrosia. I haven't found any worm/beetle holes but I'd hate to infest my shop with any wood boring insects. I work in a shared shop with about 6 other wood workers so combined we have several thousand board foot of various lumber. This is the only green wood, though there is a bit of air dried stock. Do my turning blanks belong in the yard?

I don't think you have to worry about that. Ambrosia beetles are forest bugs - I've never heard warnings about them in the shop. Now you can worry if you see powdery frass below tiny powder post beetle holes. PPBs are mostly attracted to green/wet wood. (I once saw a bunch flying towards me from the woods, some landing and starting to dig into the end grain of some log sections I was cutting up outside of my garage, likely attracted by the smell of freshly cut sugar maple.)

The picture you showed of the log sawn in half with a darker center doesn't look like ambrosia to me. I always see ambrosia beetle holes (one to three) in the middle of what are usually narrow streaks.

This page shows typical ambrosia maple, various side views and end grain pics: http://hobbithouseinc.com/personal/w...20ambrosia.htm

JKJ

[chuck van dyck]

I don't think you have to worry about that. Ambrosia beetles are forest bugs - I've never heard warnings about them in the shop. Now you can worry if you see powdery frass below tiny powder post beetle holes. PPBs are mostly attracted to green/wet wood. (I once saw a bunch flying towards me from the woods, some landing and starting to dig into the end grain of some log sections I was cutting up outside of my garage, likely attracted by the smell of freshly cut sugar maple.)

The picture you showed of the log sawn in half with a darker center doesn't look like ambrosia to me. I always see ambrosia beetle holes (one to three) in the middle of what are usually narrow streaks.

This page shows typical ambrosia maple, various side views and end grain pics: http://hobbithouseinc.com/personal/w...20ambrosia.htm

JKJ

Ah, yes! These photos clear that up pretty well. Agreed, what I have is likely not ambrosia. I was dealing with some punky dark wood on my inaugural bowl, but now I’m thinking maybe I left some of the pith.

This sure is fun!

John, thanks again for the guidance and advice.

[chuck van dyck]

Finally had a chance to turn one of the blanks. I have no idea what I'm doing, but this is very enjoyable. I don't own many bowl turning tools as I've always been focused on spindles. 1/2" bowl gouge, 1" round nose scraper, parting tool. I think that's what I used on this. I actually found it pretty hard to get to the bottom of the bowl while staying on the bevel...I'm gonna experiment with regrinding my gouge some. I think I'm at like 55*ish now but honestly can't remember. I need to buy one of those protractor things.

Walls obviously taper off pretty drastically and the bottom is a little heavy. Hit it with 80-220 and am pretty happy with the surface, although I burnished with shavings and I think I overheated the walls cause I heard a little "creek". Hairline fracture...

Anyhow, lookin forward to turning the rest eventually. I got 12 blanks and am quickly realizing, that's too many blanks, haha. If any Brooklynites wanna swing by and grab one, hit me up.

IMG_1789 (1).jpgIMG_1791.jpg

[John K Jordan]

Very nice. I like the elegant shape on the outside AND the wood! Looks like you have some interesting figure in that wood. The contrast between the dark and light is striking.

The tools you have are good. Some people get a second bowl gouge and grind it at a different angle so they can more easily cut through the "transition" and across the bottom. But smaller angle such as 40 to 45-deg may be better for sides, inside and out, and for detail and tight spots. However, the inside of a shape like yours is difficult with any gouge.

I don't turn many bowls, but when I do I use the same tools as for platters - sometimes use a bowl gouge but generally cut with a Hunter Hercules tool. This, like some other Hunter tools, can be used either as a gouge or as a scraper. I might use the Hercules or, depending on the shape, another Hunter tool as a scraper to shape the insides of a bowl shaped like yours to the wall thickness I want.

I often like to leave the bottoms a little heavy since I like the way it feels in the hand, but not too thick. If a green wood bowl is too thick in the bottom the uneven stresses from shrinking while drying can cause cracks. I don't know about burnishing with shavings but aggressive sanding while the piece is spinning can heat the wood and create more stress than if dried slowly. Someone who finish turns a lot of green wood bowls may have good advice on this.

FWIW, I've never been much of a fan of burnishing with shavings although I know many like to. I prefer to remove tool marks with a negative rake scraper, smooth with hand scrapers with the lathe off, then go directly to fine sandpaper, sanding mostly by hand with the lathe off.

When I do turn green wood bowls I almost always twice-turn them: rough turn the bowl first to fit the shape I want, leave the walls thick, then put it up to dry for a few months. When sealed and dried slowly they almost always survive without cracks. Then when completely dry I finish turn to remove the out-of-round distortion and create the final shape. Of course turning hard, dry wood can be more work than throwing easy green shavings across the room but I like to end up with a round, unwarped bowl or platter.

As for shapes, famous woodturner Richard Raffan suggests something most of us have trouble doing: he recommends periodically cutting a bowl in half as a learning experience to evaluate the cross section, saying it will lead to better shapes and pieces with better balance. I've done this a few times but I have to force myself - I hate to cut up a piece I just turned, especially if I like the shape. It's easier if the wood is unremarkable!
I have on occasion happily cut pieces in half as a teaching aid to illustrate how I shape certain things, for example, the bells of handbell Christmas ornaments:

bells_cutaway_IMG_5169.jpg

I'm really glad to hear you are a spindle turner! A number of experts agree that spindle turning teaches the fine tool control that will let you turn anything. (I always start students on spindle turning, first with a skew, then a spindle gouge.) I've known turners who started and stuck with green wood bowls and couldn't turn a spindle if they had to! Turner/teacher Frank Penta told me that in the trades, apprentice turners had to demonstrate proficiency with spindle turning before they could advance to face turning.

JKJ

Finally had a chance to turn one of the blanks. I have no idea what I'm doing, but this is very enjoyable. I don't own many bowl turning tools as I've always been focused on spindles. 1/2" bowl gouge, 1" round nose scraper, parting tool. I think that's what I used on this. I actually found it pretty hard to get to the bottom of the bowl while staying on the bevel...I'm gonna experiment with regrinding my gouge some. I think I'm at like 55*ish now but honestly can't remember. I need to buy one of those protractor things.

Walls obviously taper off pretty drastically and the bottom is a little heavy. Hit it with 80-220 and am pretty happy with the surface, although I burnished with shavings and I think I overheated the walls cause I heard a little "creek". Hairline fracture...