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Thread: Shop safety - got nailed with a broken bowl today

  1. #16
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    Quote Originally Posted by John K Jordan View Post
    Thanks so much for posting that, David. Each of us needs reminders, over and over. I wonder how many never get mentioned.

    I wonder if a sticky thread compilation for accidents and near misses would be a good thing, not necessarily diluted with public comments but a single edited message for each story with photos if available: what happened, why, what to do differently.

    JKJ
    Thanks JKJ, I know I certainly need periodic reminders. I find myself slowly getting more and more comfortable doing things that might not be completely safe but I've gotten away with in the past otherwise.

  2. #17
    Quote Originally Posted by David Brimm View Post
    ....Not sure the exact speed but somewhere in the 1800-2000 range I suspect. I was bringing the speed up to put a little wax on it and hadn't touched it yet.
    Full disclosure-- I don't use wax finishes and have not made myself all that familiar with their application. That being said, for turning, I've always followed the Bowl Diameter (in inches) X RPMs should be in the 6000-9000 range. That is, for a 12" bowl, I'd probably be in the 500 to 750 RPM range. For finishing, I generally don't stray from this range either.

    Am I ultraconservative and off base or do any others have similar rules of thumb I should be aware of?
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  3. #18
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    Spinning a 12” bowl at near 2000RPM with splits in it, (seen or unseen, they were there) is asking for trouble, you are just lucky you did not end up in the ER or worse.

    Quote :{ I find myself slowly getting more and more comfortable doing things that might not be completely safe} and that is another indication of unsafe behaviour, I would advice to change that for your own self interest.

    There are several splits in that bowl, more than the lines indicate, though a little harder to see in a picture of Oak wood, but easier when held and swivelled in the light.

    splits in Oak bowl.jpg




    Have fun and take care

  4. #19
    Quote Originally Posted by Matt Schrum View Post
    Full disclosure-- I don't use wax finishes and have not made myself all that familiar with their application. That being said, for turning, I've always followed the Bowl Diameter (in inches) X RPMs should be in the 6000-9000 range. That is, for a 12" bowl, I'd probably be in the 500 to 750 RPM range. For finishing, I generally don't stray from this range either.
    Am I ultraconservative and off base or do any others have similar rules of thumb I should be aware of?
    I use speeds similar to what you do. I've turned several hundred bowls up to 16". For bowls, I don't think I've ever used anything other than the low range speed setup (1200 rpm max), even for smaller ones, and never to that maximum. 10-12" bowls would probably be 600-700 max. And sanding much slower. I do most finishing off the lathe.

    2000 rpm means that a point on the rim of a 12" bowl travels over 6000 feet per minute, or 100 feet per *second* -- over a mile per minute. That's highway speed -- 60+ mph.

    An extensive discussion of turning speed and guidelines (uses the Diam x RPM = 6000-9000), complete with chart/graph:

    http://www.docgreenwoodturner.com/lathespeed.html

  5. #20
    Quote Originally Posted by David Brimm View Post
    I find myself slowly getting more and more comfortable doing things that might not be completely safe but I've gotten away with in the past otherwise.
    David, Bob and Leo have highlighted much of what I might say, but your statement could be described as complacency. From Merriam-Webster - "...self-satisfaction especially when accompanied by unawareness of actual dangers or deficiencies. When it comes to safety, complacency can be dangerous."

    I would encourage you do to quite the opposite - the longer you turn, the more uncomfortable you should become doing things that are not completely safe. Most of us will sometimes engage in procedures that may have an inherent danger beyond the simple act of turning, itself inherently dangerous. Those procedures may have become
    necessary to overcome a problem that has developed. But, it is the heightened sense of awareness one develops with experience that causes us to take extra precautions in those situations that are necessary to prevent injury.

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  6. #21
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    First, I am glad you did not receive any more serious injures.
    One thing I did notice is that you said the lens broke.
    There are safety glasses and there are safety glasses.
    Look for the + rating (such as Z87.1+)

    There are tons available; mine are the Dewalt bifocals (About $8 IIRC)
    Similar to these but Dewalt makes many styles. Many other quality makers out there also.
    https://www.amazon.com/DPG55-11C-Ant...safety+glasses

    Short version:
    Without the + they must withstand a 1" steel ball dropped fro 50". Test over. No cracks, good to sell.
    With the + thy must withstand a heavier pointed object dropped from the same height. AND must withstand a 1/4" steel ball at about 100 ft per second (IIRC this is about the same as a 17 cal shot). Velocity test not required if they do not have the + rating.
    The Dewalt lens and all frame parts are embossed with the + as required.
    "I became insane, with long intervals of horrible sanity." - Edgar Allan Poe

  7. #22
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    Thank you, David, not only for writing about the event, but for allowing us to analyze this for everyone's sake - your sake, my sake, and everyone else's sake. If I have a lathe on for applying finish on a bowl, I never do that fast enough for a friction-wax finish. Slowest possible speed, wiping on and buffing off by hand. I do use friction polish on narrow spindles.

    I hope that heals quickly.
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  8. #23
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    First - glad you weren't seriously injured. I'm a newer turner and I have a Beall buffing system with the Beall "buffs" and they are driven off the lathe mandrel. Is it common to buff with the piece turning (just curious)?

    Thanks,

    Mike

  9. #24
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    Quote Originally Posted by Mike Goetzke View Post
    First - glad you weren't seriously injured. I'm a newer turner and I have a Beall buffing system with the Beall "buffs" and they are driven off the lathe mandrel. Is it common to buff with the piece turning (just curious)?

    Thanks,

    Mike
    Mike there is a good discussion in this thread but there are more if you type Buffing in the forum search location.

    http://www.sawmillcreek.org/showthre...05#post2586405


    Have fun and take care

  10. #25
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    Michael whatever glasses this turner was wearing doesn’t really matter, as they are not making him safe from heavy and fast moving pieces of wood, and for small splinters or loose pieces of bark, normal safety glasses should do, the real problem is, do you think one gets to be safe with safety glasses and or face shields ????

    Have a look what it did to this turner, neither glasses or shield will make you safe.

    High speed turning accident.jpg





    Quote Originally Posted by Michael Mills View Post
    First, I am glad you did not receive any more serious injures.
    One thing I did notice is that you said the lens broke.
    There are safety glasses and there are safety glasses.
    Look for the + rating (such as Z87.1+)

    There are tons available; mine are the Dewalt bifocals (About $8 IIRC)
    Similar to these but Dewalt makes many styles. Many other quality makers out there also.
    https://www.amazon.com/DPG55-11C-Ant...safety+glasses

    Short version:
    Without the + they must withstand a 1" steel ball dropped fro 50". Test over. No cracks, good to sell.
    With the + thy must withstand a heavier pointed object dropped from the same height. AND must withstand a 1/4" steel ball at about 100 ft per second (IIRC this is about the same as a 17 cal shot). Velocity test not required if they do not have the + rating.
    The Dewalt lens and all frame parts are embossed with the + as required.


    Have fun and take care

  11. #26
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    One other danger that I did not see mentioned is that a chuck expanding in a recess can break a solid piece, and any crack or weak section is much more likely to fail. A good solid ring of wood is required for a recess to withstand the expanding chuck.

  12. #27
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    Quote Originally Posted by Thomas Canfield View Post
    One other danger that I did not see mentioned is that a chuck expanding in a recess can break a solid piece, and any crack or weak section is much more likely to fail. A good solid ring of wood is required for a recess to withstand the expanding chuck.
    Not so popular these days, but I believe a face plate can be more secure than either a recess or tenon if there is enough wood in the base, or a glue block mounted on a faceplate. A face plate can act to hold a piece together rather than pry it apart.

    But even with a faceplate and a face mask I don't think I would turn a 12" piece over about 500-600 rpm.

    I have a friend who turns even larger pieces so full of voids they would certainly come apart when cutting the inside but he has never had one break. After turning the outside he cocoons it in reinforced strapping tape before removing material from the inside.

    JKJ

  13. #28
    Exactly what I'm experiencing. I have more respect now than I did when I started. Maybe it's posts like this or my own experience. Pay attention, if you're mind drifts quit and sweep the floor. Thanks for all these posts and thanks for sharing your accident. We can all learn.

    Quote Originally Posted by John Keeton View Post
    David, Bob and Leo have highlighted much of what I might say, but your statement could be described as complacency. From Merriam-Webster - "...self-satisfaction especially when accompanied by unawareness of actual dangers or deficiencies. When it comes to safety, complacency can be dangerous."

    I would encourage you do to quite the opposite - the longer you turn, the more uncomfortable you should become doing things that are not completely safe. Most of us will sometimes engage in procedures that may have an inherent danger beyond the simple act of turning, itself inherently dangerous. Those procedures may have become
    necessary to overcome a problem that has developed. But, it is the heightened sense of awareness one develops with experience that causes us to take extra precautions in those situations that are necessary to prevent injury.

  14. #29
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    Quote Originally Posted by Leo Van Der Loo View Post
    Michael whatever glasses this turner was wearing doesn’t really matter, as they are not making him safe from heavy and fast moving pieces of wood, and for small splinters or loose pieces of bark, normal safety glasses should do, the real problem is, do you think one gets to be safe with safety glasses and or face shields ????
    Leo, I did not intend that any safety glasses will protect from all injury. As you state "normal safety glasses should do" I somewhat disagree. Go ahead and wear your "normal" $1.50 safety glasses rather than ones with the + rating. I do think the ratings matter for lots of folks (those who don't want shards of broken lens in their eyes).
    I agree that glasses and shields do not stop injury but I do think proper protection helps mitigate damage.
    The soundness of the wood, speed, proper holding method and standing out of the line of fire, etc. are more important.

    I have a shield rated V50 (IIRC), ballistic grade. I also have the Bionic which is very light and has the + rating; it may not break easily but the lens will flex enough for you to still receive major damage.
    "I became insane, with long intervals of horrible sanity." - Edgar Allan Poe

  15. #30
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    Thanks for the comments, concerns and questions everyone.. much appreciated.

    You're all absolutely right for the most part. I did many things wrong, made many mistakes and got caught. Fortunately it didn't result in serious injury to myself or my wife. In retrospect I realize the speeds we were using were way too high for a bowl (let alone of that size). This was a bad mistake on my part and in part due to my inexperience turning bowls, I've turned a dozen or two over the course of 5 years or so but 95% of my turning is spindle work (think pool cues, etc). When doing this bowl (and ones in the past I now realize) I didn't use the full speed I would have with a spindle but I didn't cut the speed back nearly far enough for this kind of job. I spend 40-60 hours a week turning spindles commercially and was so comfortable and confident in my 'skills' that I forgot physics had a say in the matter. I won't make that mistake again.

    Sometimes it's hard for us to admit failures and mistakes to ourselves, let alone others, at least it is for me. In this case though I made myself share because I wanted to take advantage of this mishap to remind/warn people of the dangers we sometimes overlook or downplay. It's a bit embarrassing but if it helps other people be a little safer going forward then it's worth it in my mind.


    Quote Originally Posted by Michael Mills View Post
    First, I am glad you did not receive any more serious injures.
    One thing I did notice is that you said the lens broke.
    There are safety glasses and there are safety glasses.
    Look for the + rating (such as Z87.1+)

    There are tons available; mine are the Dewalt bifocals (About $8 IIRC)
    Similar to these but Dewalt makes many styles. Many other quality makers out there also.
    https://www.amazon.com/DPG55-11C-Ant...safety+glasses

    Short version:
    Without the + they must withstand a 1" steel ball dropped fro 50". Test over. No cracks, good to sell.
    With the + thy must withstand a heavier pointed object dropped from the same height. AND must withstand a 1/4" steel ball at about 100 ft per second (IIRC this is about the same as a 17 cal shot). Velocity test not required if they do not have the + rating.
    The Dewalt lens and all frame parts are embossed with the + as required.
    Hi Michael, thanks for the detailed post. Being a commercial shop we buy safety glasses by the case, all are appropriately rated but are not "+" rated. To clarify my earlier comment(s) about my glasses breaking, the arms broke off (one broke, the other just detached) and the bridge across the nose cracked thru but held the glasses together until I broke them upon removal. The lens took the brunt of the impact and didn't break though it did flex enough that the poly (or whatever) turned opaque. The glasses were actually pretty cool to look at since you could see how they stopped the impact and the effect it had on them, I really wish I'd been thinking clearly enough to have the wife take a picture of them. I credit still having both eyes to those glasses.. without them I definitely (in my mind) would have lost the eye. As it is I feel lucky to have avoided any fractures around the socket.

    Anyways, again, I appreciate your post. Safety glasses are something I'm passionate about (weird right?) and no one comes into my shop without a pair on their face, even if they're just walking thru from one door to the next.


    Quote Originally Posted by John K Jordan View Post
    Thanks so much for posting that, David. Each of us needs reminders, over and over. I wonder how many never get mentioned.

    I wonder if a sticky thread compilation for accidents and near misses would be a good thing, not necessarily diluted with public comments but a single edited message for each story with photos if available: what happened, why, what to do differently.

    JKJ
    I would imagine that most accidents/incidents don't get mentioned but I don't have any data to back that up. I figure a learning experience should be used as such so really wanted to share so other could benefit from my poor decisions.

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