Discussion in 'Woodturning Discussion Forum' started by Jamie Straw, Jun 23, 2016.
Odie. Fixed it. Thanks for pointing it out.
I suppose somewhere along the line we should have asked why you think you need a thin parting tools and what your going to use it for. If your just making boxes that are 2" or less in diameter just about anything will work. I use my reground paring knife for these. If you need to Part wider boxes then the wider blade parting tools are more useful. Parting tools that are thick at the top and thinner at the bottom tend to tilt on you when you cut. Metal lathe tools are ground this way but they are clamped in a tool rest and can't tilt. Sorby makes a parting tool that is thicker in the middle. Doesn't bind as much but you have to be pretty finicky when you sharpen it because the cutting tip needs to be right on that wide area of the body of the tool.
Nick Cook developed his for his honey dippers. He didn't need a thin tool per se but needed one that left a kerf that didn't need sanding because it's hard to cut into each of those honey dipper cuts.
One of my favorite thin parting tools is a key hole saw I bought at the flea mkt for $1. Ground the teeth of and shortened it, then ground the tip to the angle I wanted. It's fantastic and comes with it's own handle. Later today I'll try to post a photo of my parting tools.
I think that is the joker....if you buy exotics and use every bit of that wood....aka Alan Batty....then a thin parting tool is a must, if you cut your own blanks from trees (note plural) maybe a thin parting tool is not so much needed
John, you know I hadn't really thought about that. Truth is I mostly use my 1/8 inch parting tool. But, when I'm doing a box with figured wood want to match the green and want to lose his little grain as possible between the lid and base then I really do like to have as thin a kerf as possible. My little veneer saw is great for small stuff, but I wouldn't want to part off a two or 3 inch diameter box with it
I have several different parting tools and my favorite is my thin parting tool. It wastes less wood, parts faster because of wasting less wood, and enables better grain matching. When I want a really thin kerf, I have a Japanese style very thin (0.005") flush cutting dowel saw. I use it with the lathe running slowly in reverse. I'm more inclined to ask myself why I need a thick parting tool, but thin parting tools aren't easy to use for really deep cuts.
For parting waste blocks from an otherwise finished bowl, I could easily get by with a standard diamond parting tool. When I got my Nick Cook "fanged" parting tool, I was doing some boxes at the time. I wanted thin, because it's very desirable to have the grain match the body and lid with as little variation as possible. A thin kerf is better for this purpose.
I've since decided that most lids will eventually not fit the body very well, given some elapsed time......no matter what you do.....unless you give them a fairly loose fit from the start. A loose fit doesn't give that satisfying aesthetic tweaking of the senses that a snug fit does.......so, it's a no-win situation. I went back to exclusively doing what I know best......bowls.
Since I already have the Nick Cook fluted parting tool, it's still my 1st choice, even though a thin kerf isn't very important to parting away the wasteblock. A clean cut is nice to have, even though it's not an absolute necessity.
BTW: When I part away the wasteblock, I always alternate the cut from left to right side of the kerf just slightly, and bring the depth into the interior approximately 1/2" at a time. This gives approximately a 110% wider kerf than the thickness of the NC parting tool, and avoids all the problems associated with a kerf that is the same size as the thickness of the tool itself.
Hey Bill, what would you say is the maximum safe diameter you would be comfortable using that saw on?
Maybe 3/4" on a good day. I think I used it once on a piece about 1 1/4 inch, but if you let the kerf get deep enough for the wood to flex and pinch the blade, something is going to give ... From my personal experience, it's much smarter to cut part way on the lathe and then stop the lathe and use the saw the right way to finish the cut. Otherwise, before the saw gets yanked out of your hand, you'll get pulled over the toolrest and knock the wood out of the lathe with your knuckles. There are better ways to take the wood off the lathe ... just trust me on that one.
A hacksaw with the blade mounted backwards works pretty well.
With the lathe in reverse on slow speed I have used it to cut 3-4"
The kerf is wider than the blade but you have to stop the lathe when there is 3/4 to 1/2" of wood remaining because when thin the piece being cut off will wobble and bind the blade.
Agree with Mark and Bill about matching grain advantage (though I've yet to make a box) But I use my current thinnish PT (cheapo from PSI) for various things in both spindle turning and bowls -- often to cheat on getting a place to start a cut with a gouge, since I haven't totally learned how to just go straight in from air when need be. I haven't done any spindle turning for several weeks, but when I was on the bottle-stopper kick, I used it fairly often. I don't anticipate a "tilting" problem with the D-way - the taper is very small and I can usually feel if a flat tool edge isn't sitting flat on the tool rest, especially the new one I have. In case someone who's lurking wants to see it in action, this video shows Dave sharpening and using it. He's having fun, can't stop parting off discs.
I'm wondering how many nicks and cuts he has on his hands. He must be like me ... I'm always getting a splinter, scrape, scratch, blister, or burn.
I noticed that too......sort of makes you wonder what you didn't see.......
For those who don't know Dave, here's a paragraph from his "About Dave" page: "Dave retired from Operating Engineers, he was a diesel mechanic, welder and fabricator for 40 years. Dave spends some of his retirement hours tending his oyster and clam beds and spoiling his cat. Dave was looking for an art medium now that he was retired, having worked with metal most of his adult life he considered metal sculpture but felt wood was a much softer medium, readily available considering the area in which he lives. Like many woodturners Dave started out working in his garage. He now turns in a large studio, approximately 3300 sq ft. on the shores of South Puget Sound."
Between the mechanic/welder/fabricator work and tending clams, yep -- he'll have lots of nicks and cuts. What's awesome is the work he does and the lathe he built. He makes gorgeous hollow forms, among other things. And if you fast forward to about 7:20 in this video, he'll tell you about his lathe.
I actually like that idea better than using my veneersaw. I could probably buy 50 hacksaw blades for the price of my saw. And since it's a little bit thinner blade less friction and grabbiness.
He's also really good guy to talk to. I bought my CBN wheels from him.
3300 s.f. shop. Wow! Mine is 9 x 27.
If you subtract three thousand then you have the size of my shop 300 square feet.
Here's my trick for getting matching grain. I use a thin parting tool. The thinner the better. I push the cut in about 1/4 to 3/8". This will now be my fulcrum for further cuts. I don't pull the parting tool all the way out. I start the second cut about 3/8" in and push in another 3/8". Move the tool to the left or right and make another cut to widen the kerf. I keep doing the same thing going deeper and deeper until I've cut the box in half. If I pull the parting tool out during this process I'm careful to insert it back into the original kerf without enlarging it. This way I get the clearance inside to keep the tool from binding but I've never widened the original cut so I get the minimum waste of wood at the lip where your box will meet. I measured my homemade thin parting tools yesterday and the small one is .035" and the bigger ones are .045 and .050". I doubt your saw will take a much thinner kerf if at all. I have used saws but my parting tools are so much faster.
...and super-helpful to those who are willing to take the trip to his shop. I've had two sessions with him -- if I need one of his tools, I pick it up rather than having it shipped. He helped me more with sharpening than all of the YouTube videos combined (no offense to John L., I just needed help from right over my shoulder).
I'd love to get up there someday. My son and a buddy spent a couple of months in the Oregon / Washington area during a summer break and he fell in love with it. There was a Christian rock weekend they attended and they ended up just staying there.
I'd love to meet Dave, buy some tools and maybe take a class. Then fill my pickup with a bunch of madrone to bring back here to bayou country.