Trouble turning a rock

[Brian Brown]

We had a bad early season snow storm today that broke branches off thousands of trees. I salvaged some of the larger stuff for turning. My problem is I got some Locust wood, and just for fun tried to make a goblet out of it. Turning the outside was really easy, but when I went to hollow it out, it was so hard, nothing would cut it. My bowl gouges couldn't touch it. They are sharp, sharpened freshly last night by my mentor. A scraper barely made a mark, so I tried the bowl gouge again. It ripped the goblet out of the chuck. Then I tried to drill a hole in it with a forstner bit at the drill press. After a lot of effort, I finally got a hole about 1 1/2 in. deep. Has anyone had any experience with Locust, and is it really this hard to make an endgrain cut, or am I just doing something wrong? How is it for making natural edge bowls? I got quite a bit, and have access to more, but I'm ready to take this to the landfill. It looks like it would be a nice looking wood, but I'm not sure it's wortth the effort! Thanks for the help.

Brian

[Dennis Peacock]

I don't know Brian. I've turned some pretty hard stuff a few times. The toughest I've had so far is some very dry, very hard Pecan as well as a chunk of Walnut that had been dry for a long time and turning it was mostly like turning concrete with a little dust mixed in. The other hard stuff I've turned was a piece of Red Oak. Hard stuff I tell ya, even cranking it up on the PM3520...what a challenge that was!!!!!

One thing is to experiment on tool presentation and pressure to the wood to see what makes a difference in how it cuts. Sometimes brute force is what it takes while other times it a very light touch with a sharp edge. The wood will tell ya if it wants to be turned or not. :rolleyes: :D

[Curt Fuller]

Same snowstorm has been dumping on us all day too. But the locust I've turned, although pretty hard, hasn't caused any of the things you mentioned. Especially not green. I would compare it to woods like hard maple or some of the exotics.

[Jim Becker]

Locust can be tough, especially if dry. If you are hollowing end-grain, try a hollowing tool which is essentially a scraper, but with a very small tip. Light cuts with engagement below center and with the tip canted a few degrees to the left should work, although you'll need to sharpen often. (which for those small tips is working the TOP of the tip with a hone, not grinding away a lot of metal from the sides)

Oh, that bowl gouge you had your mentor sharpen? It's no longer sharp. When you're working with your tools, you'll need to sharpen often; and even more frequently on especially hard material or stock that is spalted. The calcite in the latter will take an edge off in just several revolutions of the piece.

[Jim Kountz]

I remember dear ol Granddad telling me of a wood called lignum vitae (sp)?? He said that was some hard stuff too. They would make seals out of it for the drive shafts of ships...Granddaddy was the man!

[Dennis Peacock]

I remember dear ol Granddad telling me of a wood called lignum vitae (sp)?? He said that was some hard stuff too. They would make seals out of it for the drive shafts of ships...Granddaddy was the man!

Yup....and Lignum Vitae is also used a "cool blocks" for bandsaws too. ;)

[Dean Thomas]

Jim Becker is right. Locust can be some tough stuff. And of course, not all locust varieties are created equal. Some of them are like ironwood. They made fenceposts out of the stuff for a reason!! TOUGH WOOD.

If you've read this kind of explanation before, it might still be worth a glance.

Remember that all wood is essentially like a box of plastic drinking straws. If you try to do anything to the ends of plastic straws, you don't get very far--you have to go in from the side in order to shorten those straws. With wood, cutting endgrain is always tough, and some species tougher than others. If you stop trying to cut endgrain and remember that your main goal in life is to cut SIDEgrain, turning life gets easier.

There are several ways to accomplish this. One way is to drill into the center of your piece of wood, either with a spindle gouge or with a drill bit. Use a bowl gouge and start from center and move left. Keep the bevel of the bowl roughly perpendicular to the shaft, with the flute open enough to cut easily. At this point, as you move to the left, you are cutting SIDEgrain. You'll find that you can CUT a whole lot faster than you can SCRAPE and with less aggravation, IMO. Then once you've established basic shape and depth, you can get the rest of the project with appropriate tools including scrapers. Same rules apply as with any other bowl. Don't drill so deep that you have nothing in the middle to keep it strong.

Hope it helps.

[Brian Brown]

Dean,

Your advice make sense to me, but I think I may give up on this stuff for awhile, before it kills me. I cut a bowl blank with a chainsaw, and attached it to the lathe with a faceplate. As I was trying to true and balance the blank, the toolrest broke off my lathe, and banged up the end of my finger. Locust may just be too much for my little MIDI lathe. Oh well, there are alot more species brought down by this storm. When I get a new tool rest, I'll try something a little easier, or just go back to segmented work..

Brian

[Ron McKinley]

Yep, been there, done that. It does make good firewood though......Ron

[John Shuk]

Locust is also infamous for having loads of silica in it as well. Cutting dry black locust with a chainsaw is a good idea if you need to dull a chain quickly.

[Burt Alcantara]

Brian,
I'm in Boise. Last year a local aborist gave me a few honey locust logs about 6-8" in diameter. I also had a few small pieces of black locust that I can't remember where they came from.

I turned a few small bowls and boxes with no problem other then selecting the right finish. I don't think I did justice to the color and figure. I don't recall having any problems with them. I'm only turning since January of this year on a Nova 1624.

The wood was not really wet but would probably qualified as being green.

A few weeks ago I got 2 fresh honey locusts from the source. This is sitting in my storage area until I can get to it.

Locust is very hard and dense. Perhaps, because I made very small things I had better luck. The boxes are about 1.5", the bowls, if one can call them that, are about 2.5".

Don't throw it away. If you're any where near Boise let me know and we can work out a trade.

Burt