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Thread: First Platter & Mentors

  1. #1

    First Platter & Mentors

    Some have mentioned the advantages of having a mentor while learning the intricacies of woodturning. My first attempt at turning a platter provides ample proof to that claim. While I think the end result of what is shown below is OK and quoted as "nice" by my not so critical wife it nonetheless has flaws, the least of which is not being able to totally eliminate end grain tear-out. I'm still not sure how to handle it. The plate is mostly in the form of what Mike Mahoney recommends in his videos. It is about 13" in diameter with a rim thickness of about 1/4". I don't know the wood species but it really came to life after applying a heavy coat of walnut oil.
    Platter 001.jpgPlatter 002.jpg

  2. #2
    Join Date
    Sep 2012
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    Tampa Bay area
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    I think you did a pretty nice job. Thanks for posting the pictures.

  3. #3
    I think overall it looks fine. There is always some small area you can improve upon here or there, but don't beat yourself up.

  4. #4
    I would be using that every day.

  5. #5
    Even as a real young kid I knew what a flying saucer was , thatís a good one . Never liked the Frisbo plastic toys.

  6. #6
    It looks great. I don't see any flaws.
    I like the way yoou finished it.
    "All that is necessary for the triumph of evil is that good men do nothing."

    ďIf you want to know what a man's like, take a good look at how he treats his inferiors, not his equals.Ē

  7. #7
    Join Date
    Feb 2008
    Location
    E TN, near Knoxville
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    12,196

    Eliminate tearout and surface defects, my method

    Quote Originally Posted by Steve Mathews View Post
    Some have mentioned the advantages of having a mentor while learning the intricacies of woodturning. My first attempt at turning a platter provides ample proof to that claim. While I think the end result of what is shown below is OK and quoted as "nice" by my not so critical wife it nonetheless has flaws, the least of which is not being able to totally eliminate end grain tear-out. I'm still not sure how to handle it. The plate is mostly in the form of what Mike Mahoney recommends in his videos. It is about 13" in diameter with a rim thickness of about 1/4". I don't know the wood species but it really came to life after applying a heavy coat of walnut oil.
    Platter 001.jpgPlatter 002.jpg
    Steve,

    I agree that the result is "nice", actually more than nice! I like the design and form, especially the narrow rim at the outside edge the shallow dish and just inside the outer rim - I think it catches the eye, adds an interesting tactile feature, and enhances the piece. I've used a similar design in some of my pieces over the years. I've never watched any of Mahoney's video but if he uses a similar feature my opinion of him has just gone up.

    The rustic setting and background for the photo is also excellent, dynamically contrasting the smooth wood and the rough rock. Hard to tell from a photo but the wood looks diffuse porous and by the color could be cherry - you could examine the end grain with a magnifier or pay attention to the smell when turning. However, there are plenty of other species that don't look too much different though. One hint besides the smell might be the density. I have some exotic woods that look similar but they are more dense.

    Regardless, nice piece!


    Are you open to constructive feedback/criticism on the surface? If not, stop reading here!! Otherwise...

    You mentioned not knowing how to eliminate some tearout. It's much easier to tell when holding in the hand but even in the photos I do see some evidence of what may be tearout or what I sometimes call "micro-tearout". I can tell you what I see in the photos and how I would deal with it in my own turnings. I see circular bands on both the top and the bottom which are sometimes caused by the micro-tearout, shallowly torn fibers that persist in spite of considerable sanding. In the first photo I see two what may be concentric bands perhaps slightly darker than the rest of the wood in the given lighting. The second photo shows several similar concentric bands about half way between the foot and the rim. When turning the piece in the hand under directed lighting such bands sometimes change depending on the angle to the light. I also see what may be tearout on the flat just outside the foot and possibly on the foot itself. (Sure wish I could hold it in my hands.)

    The bands could also may or may not be exacerbated by slight hollows or raised areas, concentric ripples, usually easier to see when the piece is held in the hand and turned various ways when examined under point-source lights. (Diffuse lighting, such as from high fluorescent fixtures, doesn't help much.) Sometimes these bands don't show up until after the finish is applied, making them even more difficult to eliminate.

    I handle these in two ways at various points in after the finish cuts and during sanding. First, with the piece off the lathe (perhaps still in the chuck), I apply a generous amount of some liquid and immediately turn and rotate the piece under the light. Some people use mineral spirits but I prefer naphtha since it dries more quickly. The liquid does several things - it makes the surface slightly glossy so it's easy to see concentric ripples. Second, it is absorbed into rougher areas such as micro-tearout and make them more visible, especially it that brief period when the liquid is almost evaporated. Third, it can reveal scratches missed in the sanding since they will show up darker at the moment the liquid has evaporated from the smoother surrounding areas. I find the naphtha so useful I keep it in a bottle above the lathe and use it on almost every piece, applying it often between sanding steps. (another nice thing naphtha does is show me what the wood color and figure will look like after the finish is applied)

    Some ways I deal with these defects:

    • First, of course, razor sharp tools. If a gouge will not shave arm hairs it's not sharp enough!

    • Make very light finishing cuts. BTW, I start "practicing" my finish cut while removing wood before I get to the desired shape. After a half dozen practice finish cuts my hands and arms learn the shape and wood and I've kind of tuned my fine control to that surface. In talking with another turner we found we both to that, sometimes even starting practicing far earlier in the process, sometimes experimenting with different tools and different grinds in the process.

    • Finish cuts are followed by shear scraping or my preference, good negative rake scrapers. My favorite NRS for these types of pieces are ground from Thompson steel with my own grind, one modified and I think improved from what I've seen in use by experts and for sale. I'll put pictures below in case anyone is interested. After smoothing with the NRS I feel carefully for imperfections and mark any I find with a pencil for touchup with the NRS. All this is before sanding - I normally do little or no sanding when the piece is rotating on the lathe.

    • I remove the piece from the lathe (I leave it in the chuck) and examine it in good lighting. If needed, I put it back on the lathe for a touchup. Note that since I first hold the front/top until the bottom is shaped, smoothed, and finished, all this is first just on the bottom/back, repeated later for the other side.

    • All further smoothing is off the lathe. I start with hand scrapers, generally curved. I shape most of these from cabinet scrapers and sharpen them the same way. I'll also put a few pictures of these below.

    • The curved scrapers are my primary weapon for removing any remaining tool marks, micro-tearout, and scratches. I've written here about the process but briefly, I work "downhill" and either directly with the grain or at some angle from the grain direction - maybe up to 30-deg or a little more, depending on how it's working. In some cases the figure of the wood dictates a significant departure from the nominal grain direction. Note that the hand scrapers must be SHARP and have a good burnished burr.

    • Note that if hand scraping does NOT remove the tearout, it's probably because deep fibers are torn out. This may need additional and more aggressive NRS or even another finish pass (with sharper tools this time!) BTW, another thing that can help with problematic tearout is treating the area first with sander sealer before the finish pass or even make the last pass with the piece wet, perhaps with mineral oil. In real problem cases with junky wood I'll resort to stabilizing the wood, sometimes with fine CA glue.

    • Hand scraping eliminates the need for coarse sanding and especially, rotary sanding. After the piece is scraped smooth I'll use a fine sandpaper by hand, all over, usually 400 grit, sometimes 600 grit. I have some small platters that 600 grit was the only sandpaper needed, period. On flat surfaces and surfaces without deep curves I often use a pneumatic random orbital sander at a very low speed and with fine or very fine sandpaper.

    • After sanding and a last minute inspection with the naphtha on that side I often apply finish. The result should be a surface, completely free of tearout, ripples, and other defects.

    • Repeat with the other side.


    Note that I do all the scraping and sanding by hand with the piece removed from the lathe. I used to leave it on the lathe, lock it in a particular position, and bend over to work on it by hand. I found this hard on the back and difficult to see properly. My life changed when I bought a carving and finishing stand. This is mounted in the banjo and is threaded to fit the chuck. I unscrew the chuck and mount it on the stand, tilting to a comfortable position. This makes it MUCH easier to see and evaluate the surface.

    I've written about all this several times in the past so sorry if you've seen it before. I've also shown lots of photos. Just in case someone is interested I'll repeat some of those photos here.

    My negative rake scraper design, 60-deg included angle, ground far down one side and flat at the tip. The bevel is equal on both sides so I can change which side is the cutting side by changing the burr. I hold these in the hand, no handle needed. I sharpen on 600 grit CBN, hone away the grinder burr, and apply a smooth burr with a carbide burnisher. I make both "left" and "right" handed versions as needed. When one gets dull the edge can be revived with an extra fine diamond hone and the burnisher.

    _scrapers_IMG_7778.jpg scrapers_neg_rake.jpg NRS_curved.jpg

    A few of my curved hand scrapers. The two on the left are Stew-Mac scrapers, also useful. I shape the curves on a 1" wide belt sander with coarse grit - this keeps the steel much cooler then shaping with a grinding wheel. I sharpen them at 90-deg with a 600 grit CBN wheel, hone away the grinding burr and burnish a smooth burr.

    scrapers_favorite_IMG_7870.jpg _scrapers_IMG_7818.jpg _scrapers_IMG_7499_e.jpg

    The carving and finishing stand, Best Wood Tools. Can't turn without it. I think the features and controls on this one are far more useful than the competition.

    carvinig_stand_A.jpg

    A 3" pneumatic ROS in use by student, on a shallow curve. I also use a 2" Grex pneumatic ROS at times. However, most sanding is by hand, usually with small pieces of sand paper backed by a soft rubber eraser. After hand scraping, very little sanding is needed.

    sanding_IMG_20171212_094330_319.jpg

    Any questions, just ask. Or come visit for hands-on private mentoring!

    JKJ

  8. #8
    Thanks for the finishing lesson John. I need it.

  9. #9
    John, what is that tool in the middle of the two scrapers in the second picture? Nomenclature and use? Awesome post btw.

  10. #10
    Join Date
    Feb 2008
    Location
    E TN, near Knoxville
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    12,196
    Quote Originally Posted by John Kananis View Post
    John, what is that tool in the middle of the two scrapers in the second picture? Nomenclature and use? Awesome post btw.
    Thanks. Iím (very) slowly converting turners to some of the techniques that have save me SO much time and Iíve found to work so well.

    Sorry for confusion, I didnít label the picture well. The tool in the middle of the second picture is actually the same tool in the middle of the first picture but turned up 90-deg to rest on the flat edge. I wanted to show how I grind the two bevels equal for more flexibility to put the curved side on the left or right in use. In practice, of course, the two bevels can be ground almost any way as long as the included angle is less than 90-deg.

    All these are Thompson 10V steel. I shaped two from Thompson scrapers but the middle one is from a Thompson skew (note one rounded edge).

    I started out shaping these (and other tools) with an 80-grit CBN wheel but then switched to a 60-grit CBN - either way they take a while to grind! Occasionally I wish I had a 40-grit but I don't shape a tool from scratch very often.

    I sharpen all scrapers with a 600-grit CBN wheel, hone/strop off the grinder burr, and (IMO) create a more useful burr with a carbide burnisher. (These days I use the Arno burnisher: https://lostartpress.com/products/arno-burnishers) I wrote about this in the past but in case anyone interested missed it, I make gauges to set the angles on the grinder perfectly every time without trial and error. I first establish the angle then shape a piece of clear plexiglas with a flat for the rest and a curve for the wheel. I cut the plastic roughly to shape, make sure the bottom is flat, then refine the rounded edge by pressing against the wheel. I found that painting one side white made them much easier to read. For these scrapers I made one gauge with a 60-deg angle. (I usually make a different angle on the other end)

    (This picture shows all three with the sharpened edge up, the one made from a skew on the right.)

    NRS_IMG_7907.jpg

    This one is to set a 90-deg angle for the curved hand scrapers and the Stew-Mac scrapers:

    hand_scraper_setup_IMG_7898.jpg scraper_CBN_IMG_7894.jpg

    I use more than a dozen scrapers for smoothing. A few more pics of some in use:

    scraper_IMG_20150723_095603_525.jpg scraper_bowl_IMG_7856.jpg scraper_box_IMG_20171220_113442_765.jpg scraper_box_IMG_20171220_113048_415-1.jpg scraper-shavings-IMG_7864.jpg

    Sorry, I got carried away again. But NRS and hand scrapers work so well I get a little passionate! I see so many people making clouds of dust with coarse rotary disk when I know, for me at least, there is a way to do it more quickly and get a better result. Maybe some day I'll find time to make a video about all this.

    JKJ

  11. #11
    Great, thank you again!

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