Turning Large Wooden Bowls

I really like bowl turning. And what I wanna talk about here is turning big chunks of wood on your leg. So, first off, what's the deal with this blank? This is a piece of butternut, dripping wet green. That means it's heavy. We're gonna talk more about that in a sec. What it started as is a piece of crotch wood from a tree. And what I did is I roughed it out to get it to a point where it's reasonably round mounted on a chuck that I could get onto the lathe there. Now, why are we going down this road? When I work with these really big chunks it gives me the opportunity to turn a large bowl. You'll also notice that we're a little off balance here. This is gonna end up as a natural rim bowl. I love how those look, but we have to deal with the fact that our whole blank here is a little bit off balance. So what are we looking for? On your lathe, we wanna have a machine that's got some mass to it. So what that means is that we've got a bed and a leg system that is steel cast iron. Lot of weight, lot of mass, so that if this does spin with some vibration, it can dampen that vibration. Additionally, with the vibration, we wanna make sure that when stuff is locked down, it's gonna stay locked down. So we wanna make sure that these handles are really doing their job and keeping things in place. One of the most important things is speed control. Because we're eccentric here, we can't just turn this baby on at a real high RPM. What we really want to do is dial the RPM in to a point where it's safe. So as I work with the speed control here what I'm looking for is the highest that I can turn this without it bouncing all over the floor. And that's why this variable speed control is really nice 'cause it's really infinitely variable. And it lets me dial that in to just the right spot. Gonna try there. So what I'm looking for is the point where maybe the layers starts to shimmy just a little bit. And I wanna be below that point 'cause I don't want the lathe bouncing around. Next thing we need here is low-end torque. We're gonna start cutting this using a scraping technique. And in order for that to happen, the lathe has to keep up with the work that I'm trying to do. So, low-end torque means that when I apply the chisel to the work, we're not gonna stop the bowl. The lathe is gonna be able to power through, give everything a final lockdown here. Let's start cutting. Now our end goal at this point is simply to get this round. Now that I've taken a little wood off, we can bring the tool rest in, always checking to make sure the tool rest doesn't hit. Second verse same as the first. As this starts to round out, I'll be able to increase my RPM. Which is a benefit to getting good cut quality. Let's talk about where we're going with this. And then I'm just gonna get back to turning. 'Cause this is a blast. This is the bottom of the bowl. Chuck is currently temporarily holding the top of the bowl. I'm gonna keep rounding, rounding, rounding, generate the shape down here. Got some beautiful butter nut grain starting to come through. Put a recess in the bottom, that'll accept the chuck. Then we'll turn this whole thing around. So I'm just gonna keep on keeping on, taking away everything that doesn't look like a bowl. What do you think? This is pretty cool. I'm real happy with it. Here's where we're at. I switched from my scraper to a bowl gauge to optimize the surface finish. Now we talked about the wood being green. So as you see those shavings coming zinging off of here like pieces of spaghetti, part of that is the impact of the fact that this is some greenwood. Now, the other thing I've done is created a recess down here on the bottom. I gonna finished that, which means I'm gonna get that cone out of the center. That's gonna allow me to turn this whole assembly around and start hollowing the inside of it. Which I can't wait to do. Real happy with the outside, looking forward to get the inside hollowed out. All right. This butternut bowl is really coming along. Couple things to point out here. One, notice that my tool rest is out here and I'm working on the side of the bowl. That's away from me instead of near me. This is a great feature, which is about having reverse on the lathe from a body dynamic. What it means is that, I can stand and turn like this instead of leaning over the lathe to turn on the inside face over here. So currently we're running the lathe in reverse, in order to work on that edge. Back to using the scraping technique to get my hollowing going here. And then when I have a bunch of wood out of there, I'll go back to the shearing technique to optimize my surface finish. Tool rest is backed up or tailstock is backed out of the way to make sure that I don't inadvertently bump my elbow. As I'm working on hollowing the inside. I got a lot of wood to come out of here yet. I predicted this would be about a 30 gallon day which is the shavings we're producing. And I think I'm pretty close to right on that. So back to work for me, we'll come back and have a look, when I'm a little further along on the inside there. That butternut bowl is really coming along. The inside is really dynamic. There's a lot of green going inside there, little punky spot. We'll what happens there as I go. I've got a lot of wood to take out of that yet. Let's talk about working with greenwood and what needs to happen next. Variety of ways that you can deal with this. One is take out a bunch of wood, but leave a thick wall, let that dry. And then after it's completely dry and it's gone kinda egg shaped on you, come back and finish the turning. Also, if you look on the internet, you'll find stabilizers. You can use chemicals to stabilize the wood that prevents that cracking and egg shaping from happening. By stabilizing the cells of the wood themselves. So just poke around a little bit. There's a lot of information out there, about working with greenwood and stabilizing it. Following the turning. I'm gonna come back, finish my turning. However, there's something else about working with large bowl blanks I wanna show you. For a little bit here I'm gonna take this bowl off, make some changes on the machine here, show you what I'm talking about. In the world of lathe buying advice. If you're gonna turn big bowls, here's something to look for. What I've done here is slid the headstock all the way down to the end of the bed on this particular machine. And for the first time, we can kinda see what this 20 inch extension down here is for. With a head stack down here and my tool rest and banjo and extension on that 20 inch extension. That gives me a really big diameter capacity here off the end of the machine. Turning big bowls, a lot of stuff going on here. It's a great way to take advantage of logs that you can get probably for free. It's a great way to get big chunks of wood, so we can get the lathe, get large diameter, deep bowls. Remember those techniques I talked about for dealing with that greenwood. Try working with greenwood, try working with those large bowls. It's a lot of fun, more than you. It's a very addictive hobby.