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Thread: Is This Bad Practice
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23rd September 2023, 08:11 AM #1
Is This Bad Practice
I am not a turner and am mostly self-taught.
I have discovered that with a light touch I can use the top edge of a spindle gouge with a fingernail grind as almost a scraper cutting inside curves very nicely and getting lovely fine ribbon shavings.
I am cutting up the hill against the grain - it helps me to get a nice radius easily and the surface quality is decent like any scraped surface.
Is this bad practice?
I assume a dedicated scraper would be preferred for this job but I only have a core set of good tools.
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23rd September 2023, 09:16 AM #2Senior Member
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In my book, the shavings answe your question. Fine curls like those in your pic are a good sign. Scraping with a gouge is a good option and provided you use a deft touch will often give a good finish.
my rule is if it works it is good. I only look for answers when there are problems.
Bruce
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23rd September 2023, 09:40 AM #3
You will get a better finish off the tool if you cut downhill with the wood grain. However, if you don't do much woodturning you may not get to do enough of it to get the hang of it.
Typically, accomplished spindle turners do very little scraping.
But, not all of us get to become that accomplished...Stay sharp and stay safe!
Neil
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23rd September 2023, 11:04 AM #4
Yes the shaving is lovely
I only use it for refinement and I start doing the bulk with detail gouge use normally but sometimes struggle to get the exact shape - a question of hand techniques getting that thrust, twist and lift of the gouge coordinated - I use this just to refine that curve a touch.
Have two more mallets to turn today will try going downhill for a better finish - but I think I have been going uphill because it is a pulling action I much prefer to pull the tool then push.
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23rd September 2023, 11:47 AM #5
I find using a gouge that way is fine until it goes bad when the upper edges catch. That can happen doing deeper coves if using a gouge as a scraper.
I gave up trying only to use gouge and detail gouge to finish perfectly these U shaped coves . Specially on larger stuff like this 200 x 200 oak column. I may rough them in with gouge rolling them in from left and right the right way or starting them in a scraping action but I now have a couple of radiused scrapers that get them finished right safely.
The risk is not physical injury that worries me doing these coves its having to do the job twice if it goes badly wrong. There's a bit of time and wood involved getting a large turning like that ready for turning. Thank goodness for scrapers.
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23rd September 2023, 12:48 PM #6
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23rd September 2023, 01:03 PM #7
Given how large and where that 'half cove' is on the piece, you could still pull it downhill to finish with a scraping cut (using the other wing) to minimise any tear out, i.e., if there is any. Some woods are less fussy than others with that.
Maybe try it out on a piece of scrap pinus crapiata first to see how that works for you.Stay sharp and stay safe!
Neil
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23rd September 2023, 01:09 PM #8SENIOR MEMBER
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23rd September 2023, 04:58 PM #9
Is it bad practice? - depends!
Auscab highlights "The risk is not physical injury that worries me doing these coves its having to do the job twice if it goes badly wrong. There's a bit of time and wood involved getting a large turning like that ready for turning."
The one rule in wood turning that is paramount to me is there are no absolute rules that will always work.
Wood is not a homogeneous material, it varies in density, grain can go every which way in some blanks, and at times it seems to defy logic and the laws of physics. I guess that is why we like using it, the challenges, the beauty etc. However, traditional hand turning presents significant hazards and risk that must be managed.
What we should be seeking is "certainty" - the state of being completely confident or having no doubt about something.
That comes through developing systems of work, techniques, etc, that create certainty in the consistency & quality of the output and in protecting the well being of the turner, and those who may potentially be affected by the turners activity. Part of that "certainty" is developing the knowledge and skills through learning and experience to select the tools, grind selection, tool presentation techniques, and the particular combination of them that offers the highest probability of success with least harm - certainty!
One thing we often lose sight of in wood turning is that the cutting edge of the tool is what does the work. How that cutting edge is presented to the work and how it is managed, controlled, and the ease of manipulation of the cutting edge to optimize it's performance and quality of the output is highly dependent upon the tool design.
The tool design, shaft & handle length, shape, physical dimensions, flute shape (if any), the grind and consistency of the grind (smooth flowing or multi-faceted???), overhang past the tool rest, the tool presentation (pitch, roll, yaw), etc all contribute to the cutting edges performance and the certainty of how it will perform in any given circumstance/s.
The overall tool design offers the turner a high degree of certainty in knowing the orientation of the cutting edge when it is presented to the work and in controlling it in use. In combination with the lathe axis, tool post setup etc it creates a reference system - which offers certainty, no guess work about where the cutting edge and the portion of it that we intend to do the actual cutting is in that reference system and with respect to the blank.
Then we consider the what if's - what happens if the cutting action does no proceed as planned - we get a catch ..... or a poor surface finish? How do we control the tool to prevent a catch? How do we counter the cutting forces - both planned and unplanned (a catch)? Could we respond in sufficient time to minimize the harm from a catch?
That's where tool selection, presentation, technique, knowledge, experience and skill of the turner combine to make a huge difference ..... as Rob mentions a scraper offers more certainty .....
A scraper offers higher probability in managing the final refinement cutting process - a long handle of a scraper to counter the cutting forces, relatively large movements in pitch, roll, yaw of the tool handle are required to manipulate the cutting edge - the handle end must move 10 times or more in range compared to the cutting edge movement.
vs
an almost direct 1 to 1 relationship & strong wrist to manage the cut or a violent roll action in a catch with the wing of a spindle gouge.
It's all about mechanical advantage, leverage .... certainty! No harm, financially or physically.
Is it bad practice to select a combination that works .... depends ..... is there a "better" method that offers "more" certainty?Mobyturns
In An Instant Your Life CanChange Forever
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24th September 2023, 07:42 AM #10
Thank you for your feedback - I now will say that it falls into the area of not-best practice. And that skilled application of a spindle is recommended however in a pinch a dedicated scarper will suffice.
I tried cutting downhill and it took more practice but as expected the surface finish was better I can also confirm that the tool does have a tendency to drop during use - if the tool rest does not offer full support the tool and if to much of the tool's edge was presented to the work.
However, I feel the temptation to use the technique will continue as it is easier to use the tool in hand to do a quick touch scrape than to grab a dedicated tool that you may not even have.
Proceed at your own risk!
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24th September 2023, 10:08 AM #11
We all succumb to the temptation of "efficiency" at some point - saving a few seconds changing tools can become costly as Rob pointed out above.
Best Practice - hmmm another one of those misused or over used terms, one of my pet peeves the term "evidence based practice" - isn't that what we all should be basing our decision making upon??? Theory is fine, but proven consistent practical results speak afaic.
If the tool/s and machinery is all that is available to you, or the only one you have, and you can consistently achieve an acceptable result without harming your self then I guess its "best practice" until something "better" comes your way.
Every thing in life is - Proceed at your own risk!Mobyturns
In An Instant Your Life CanChange Forever
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24th September 2023, 01:43 PM #12
Is a terrible term and it speaks to the infestation of the human sphere of existence with the priorities of economic and political rationalism which itself is just a facade for the capitalist imperative forever greater efficiency in the never-ending pursuit of profits at the expense of everything.
I used to work in education only those who had data were allowed to speak and then only if that data served the interest of turning a profit.
Best Practive == Higest Profit
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24th September 2023, 03:10 PM #13Mobyturns
In An Instant Your Life CanChange Forever
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29th September 2023, 12:07 PM #14GOLD MEMBER
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Going on the picture you posted, it appears you are left handed, if so; you could consider doing the mallet in a mirror image version of what you have shown.
This may help you do the longer downward sloping cuts easier, as you are favouring your dominant hand somewhat.
Mick.
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30th September 2023, 12:46 AM #15
Interesting thread, I've been following along but didn't have much to say. However, I've noticed that one aspect hasn't been covered.
Every type of turning tool has a safety envelope that, once you exceed, quickly enters the realm of "Here There Be Dragons."
Once you start using a tool in ways that it wasn't particularly designed for, such as in this case using a gouge as a scraper, you are close to the limits.
I'm not saying that it can't be safely done, nor am I saying that the tool won't perform efficiently used in this alternate way... but what I am saying is that the safe working margins are greatly reduced. Reduced margin for error = increased chance of Brown Pants.
Is it bad practise? I don't think so. It is good practise in the sense that it allows you to learn the limits of the tool when used that way. Practise, practise, practise after all.
What is bad practise is to make it a regular staple of your turning repertoire instead of learning the skills to do the same thing with a tool designed for that type of work. With a larger safe envelope.
Once your skills are at the point where it's just as easy to do it either way, you also have the experience to make an informed choice as to the better method for the job at hand. (And hopefullly the experience to cover it up when things go wrong anyway. )
- Andy Mc
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