my NE disaster

[Michael James]

My 1st attempt:
OK, this chunk of wood was shaved off the heartwood and sitting on my fireplace pile for next spark up come wintertime. It looked fairly dry, certainly drier than when I cut it. Jeff has introduced me to anchorseal and all my other green stuff is sealed. I know that now.
The tree is chinese elm which is EVERYWHERE in this metro area due to an early mover n shaker importing them to shade up the town (circa 1920 or so). Ive never seen it finished so I thught Id take what Im learing here and give it a go, full well realizing it was not going to end up a keeper. I think with some oil, Im going to like the wood. It was from a tree a friend grew up with on his dad's ranch, so the goal is ultimately a sentimental piece.
The shape was coming along ok, and as I was getting my depth, and started to thin out the edges it caught a crack and here we are. I dont feel bad about the break, usually its because Im experimenting and attemptiing to do something that the tool was not designed to do.

Question: How to you get the bark to "cooperate" when you get to the final thickness. Do you stop the lathe and hand sand the edge? Use a sharp knife, chisel? All hints tips and general comments are welcome.
The pics are from the cell phone, again, but I think their clear enough to see what happened, and what Im asking. Thanks in advance!
mj
ps - I see the other new NE post an will read that, but I think my question is different (remember Im a newbie!:))

[John Keeton]

Michael, I have very limited experience with NE stuff, but in looking at the piece of wood it appears to have several cracks. Taking a piece like that to a wide, thin form would be challenging to say the least. I think you would do much better with NE work to do it when the piece is very green - but, having only done a couple, you will get better advise from others.

I will say, however, that it does look like the elm will finish out nicely.

[Dennis Ford]

From your description, it sounds like your sequence of cuts was part of the problem. The wood having some cracks when starting may have contributed to the blow-up also.

When you want thin walls, especially on a natural edge piece, turn the inside in sections. Turn it to a shallow depth with finished wall thickness and then increase the depth and finish the wall thickness on that section. Do not go back to a previously turned section except to blend it with the next section. A negative rake scraper (or really good technique with a gouge) will allow you to touch up a little bit but I consider this risky.

[Nathan Hawkes]

Dennis's response is spot on. As the turning progresses on the inside, the bowl is starting to move (warp) due to water constantly flying out of the endgrain and changing the moisture content of the whole piece. In other words, as you are hollowing the bowl, it is warping slowly but constantly. Always sharpen your tools more than you think you need to, take very deliberate cuts, and work on that one section at a time. I stop the lathe frequently with interior hollowing and use my hands to feel the surface, and calipers to check the uniformity of the wall thickness. Also, be sure to check for end grain checks before you start hollowing. CA glue may help, but turning away the crack is the only sure way to keep them from ruining your bowl.

[Michael James]

I didnt consider opening a bowl up the same as hollowing out, but duuuuh...I guess it is. I saw the cracks, took no precaution, and was NOT surprized by the catch... but assuming that I got it to shape on the next one, heeding these suggestions... do you have to hand smooth / finish sand the bark-y edge? I cannot even guess how else to do it.

ps - put a coat of 50-50 tung oil on it, and it really brought out the yellows, lightening up the brown..... I'll try some BLO on another spot

Thanks gang! :D

[Allen Neighbors]

Michael, you've got some good advice here. I'd like to add a little bit of my technique (if you could call it that).
When I turn a piece and want to leave the bark on it, I first shape the outside. As soon as I first get to the wood under the bark, I stop the lathe, and put a lacquer wash on the wood where I've turned, then I CA the cambium layer under the bark. (Lacquer wash 65% Lacquer/35%Thinner). The wash keeps the super glue from staining the wood. I then shape some more, then the wash, and more CA. I keep this up until I have gotten the bark bared all the way around the bowl. Then I finish shaping the outside.
I then do the inside the same way. When turning the inside away, I go from the rim toward the center, to bare the bark. Going from the center out to the bark will nearly always take the bark off. After you get the bark edge shaped, don't come back to it, like was previously said. I do both, green and dry wood this same way. Sharp tools, and light cuts, as fast as you can safely spin it. Have fun!!!

[Nathan Hawkes]

As far as the bark, and sanding in general is concerned with natural edge pieces, I always sand with the lathe stopped. I make my own sanding mandrels from foam and MDF discs, and threaded inserts. This way, I have 1 mandrel per grit, and can (sometimes) use a sanding disc for more than 1 project. Usually I use a couple of each grit per piece, depending on size. Sorry for the tangent. My point is that you need to be very gentle with the bark --I only sand away the worst tool marks with 100 or 150 grit that i can't remove when I'm turning it, and then don't touch the bark again until 400grit or higher, and then ONLY to get the scratches out that are huge--I don't worry about getting the bark "shiny" smooth. Also, its a lot easier to keep the sapwood from getting "muddy" looking if you don't sand the bark. I use an air compressor to blow off the dust between grits. There isn't any way to keep the bark even, or even attatched for that matter, if you try and sand with the lathe turning.

Edit: I sometimes use CA glue, sometimes not. It depends on the the time of year the tree is cut. Typically logs cut in the winter months have tight bark, and those cut in the summer will lose their bark due to the huge amount of sap in the tree. At least that's what I've heard, and its been my experience as well. I used to try and saturate it until I found that some woods will show staining from the CA glue after they start to age with sunlight exposure, even if you don't see it right away. For me, that's a big factor, but not for everyone. I now use it mostly just to stiffen up soft spots in the bark. Also, its worth noting that whenever you're using large amounts, or really any amount of CA glue, USE A RESPIRATOR! CA glue produces TOXIC gas.