bowl turning, grain direction?

[Brad Pearce]

I'm planning on turning some hard maple salad bowls made from glued-up pieces that I can section with my bandsaw. Question is, is it better to align the grain such that I'm turning with grain outside the bowl or the reverse. In this case, all interior turning would be end grain but the outside might look better?
Thanks, Brad Pearce

[Dick Strauss]

Brad,
You'll have the easiest time getting clean cuts by aligning all of the side grain around the perimeter of the bowl.

Normally a bowl blank consists of side grain and end grain. The end grain portion is the area hardest to to cut cleanly and usually requires more sanding to make it look nice.

I hope I answered your question...

[Sean Hughto]

I'm very new at turning, but I have a good deal of expereince in flat woodworking. I think you might want to avoid setting it up so you are hollowing out endgrain in a bowl (as opposed to a small round box or vase) as the strength of the bowl may be compromised. Think of the grain as a bundle of straws. If you hollow out the middle of that bundle and also undercut the sides to form the curves, depending upon the form, you might well end up with some very short grain at the curve near the bottom. In other words, the bottom of the bowl might break out.

Now I'll sit back and wait for all the pro turners here to tell me how misguided and wrong I am. I welcome it, as I'm always happy to be set straight, if my intuition is misguided. ;-)

[Mike Minto]

correct me if i'm wrong; i may be mis-understanding your proposal. if you have the wood laid so that you have end grain inside the bowl, you must also have end grain outside the bowl. to have end grain inside or outside, and not on the other, the grain would have to bend 90 degrees, yes? usually with segmented turning the end grain ends are glued together to make rings, with edge or face grain to the inside/outside. mike

[Mark Burge]

I've been watching this thread with the same thought that Mike had, except he explained it better than I could have. But the other thing that I thought maybe you were saying was that the grain of a board leaning in a particular direction. Like when you are hand planing and you need to go in only one direction to get a clean cut. That type of grain direction does not usually seem problematic on the bowls I have made. The orientation of a bowl means that sometimes you will be cutting up hill and sometimes down hill in relation to the grain of the wood. The only noticeable places where the cut is affected is on the end grain sections. That is where tearout is a problem. Light cuts and sharp tools are the solution to that issue.

[Brad Pearce]

All of you have good comments. I didn't clearly state my question. I realize that you are going to have side and end grain exposed regardless. However, it seems that if the end grain is parallel to the lathe drive versus a 90 degree angle you might have a bias in how easy it is to turn and how it looks. I glued the 1 3/4" square maple sections so that their edge-grain is exposed top to bottom. So naively, is there a direction that best preserves that look? Perhaps it really does not matter with a bowl?

[Sean Hughto]

Your question is still unclear to me. I drew a picture that may help. If you are asking whether the red layout for a bowl is better than the blue, the answer is no, IMO, for the reasons I stated in my first response above.

[Brad Pearce]

Sean, thanks for taking the time to do the drawing. This is hard to describe. The bowls I'm considering would be made from either (A) sixteen of the pieces the way you have four drawn [giving a 7" square rectangular tube] or (B) a set of eight, made by two of yours side-by-side. Setup A would be sectioned at the bandsaw in roughly 4" slices [7x7x4"] to give an end-grain parallel to the lathe drive center. For setup B, the sections would be cut in 7" squares [7x7x31/2"] and mounted so that the end-grain would be orthogonal or 90 degrees to the lathe drive center. So in setup A, the bowl hollowing would be directly into the end grain with side grain exposure on the sides. For setup B the reverse would be true. Textbook turning tells one to use side grain or parallel grain direction for spindles and end grain direction for faceplates. It makes sense for these extreme examples of shape. However, a bowl is somewhere in between, thus my questioning what might be better. Again, I would like to keep the really neat appearance of the edge-grain maple, which almost looks curly-like. Hopefully this makes more sense.

[Richard Madison]

Brad,
For bowls you typically want the wood grain direction perpendicular to the axis of the lathe, as already mentioned. It almost sounds as if you're asking whether the edge grain or the face grain should be toward the inside and outside of the bowl. To restate, edge grain in and out would give you face grain top and bottom. And vice versa. In that case it mostly just depends on the wood and how you want the finished product to look. It's your call.

[Brad Pearce]

Richard, you have it, although perhaps hard to say without some experimentation. I'm leaning toward my described setup B, which is the wood grain perpendicular to the lathe axis as you state, also the same as the blue circle as drawn and described by Sean. I'll post some pics when done...