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View Full Version : Turning Blanks, Roughing Gouge vs. Skew Chisel



Klingwrap
25th November 2018, 02:10 PM
Hi, I am new to wood turning and don't have much experience. I have been mostly learning from YouTube videos. It seems that the majority of people out there use a roughing gouge to turn square wood down to cylinders and I have had great results using this method. Last night I found a video of someone using a skew chisel to do the same thing, and was wondering if there are any pros and cons for using either tool.

Thanks

Pat
25th November 2018, 02:40 PM
It depends on the size of the turning blank. I'll rough down with a skew up to 30mm square. I am competent, confident and comfortable with doing this. Over that, I find it quicker to round with a SRG.

It would be better if you got some one on one instruction from a competent instructor. There are a lot of clubs in the country with competent mentors and it takes alot of the trial by error out the equation. There are also a few qualified turners that can teach.

If you want to supply a location a little more specific, then we might be able to point you in the right direction.

Klingwrap
25th November 2018, 02:52 PM
Thanks,
I'm taking a beginners course at the Derwent Valley School of Creative Woodwork in Tasmania this coming January, but I'm a bit impatient when it comes to learning new things and just couldn't wait that long to find out.

Old Croc
25th November 2018, 09:39 PM
My only comment is that I sharpen and hone my skew to razor sharp so I don't want to waste it when a SRG or a bowl gouge will do the job.
Rgds
Crocy.

Skew ChiDAMN!!
25th November 2018, 11:02 PM
Both work fine - once you master the techniques - but while a roughing gouge is made specifically for roughing down, a skew is not.

A properly sharpened skew doesn't have much "meat" in the cutting edge which means it is prone to blunting a bit more quickly as well as being susceptible to chipping, etc. that a RG would take in it's stride.

So, for large blanks I tend to side with Old Croc in this one. (Mind you, having said all that, if I'm roughing a pen blank I'm much more likely to reach for a skew. :D)

Paul39
26th November 2018, 05:11 AM
My only comment is that I sharpen and hone my skew to razor sharp so I don't want to waste it when a SRG or a bowl gouge will do the job.
Crocy.

I'm with Crocy. For years I did not have a roughing gouge and used a piece of 5/8 inch square mystery metal ground to a half round on the front with about an 80 degree relief. More or less a heavy scraper, fast and easy to sharpen. I still use it for dirty timber, stumps, or something that may have rocks, wire, or nails, etc.
I

Mobyturns
26th November 2018, 06:08 AM
I use both.

My advice to beginners and to more experienced turners - select & use tools that offer certainty in the result i.e. ones that present the fewest problems. In most instances for roughing down square ish blanks to round that happens to be the Spindle Roughing Gouge or SRG.

Skews have received a bad wrap as notoriously difficult to use however they are a very versatile, safe and efficient tool when used correctly. Most of that reputation comes from turners using blunt skews and not receiving good training on how to use them efficiently and thus scaring themselves with bad catches.

I strongly recommend that initial skew chisel tuition is done between centres using a standard (or ring) dead centre or "safety drive centre" in the headstock as the "drive dog" with sufficient tailstock pressure and starting with small spindle blanks 25 to 30 mm square from softish wood or more preferably ones that already have the corners knocked off. The dead centre acts like a clutch, and will spin with minimal tailstock pressure, so when the beginner creates a catch the blank stops while the dead centre "slips." No harm done, no confidence draining scare and no dirty underwear!

Once the basics are mastered and the turner has gained confidence move up to a standard four prong drive with no "clutch protection" and progressively larger blanks, then progress onto holding the blank in a standard four jaw scroll chuck with tail stock support then onto the more advanced techniques of chuck without tailstock support. The four prong drive "may" slip in a really bad catch, but a chuck held blank definitely will not!

Once you attain an intermediate skill level you will reach for the skew in preference to the SRG when roughing down high value smaller or laminated blanks.

You will also start to gain an appreciation on the physics of tool use and the benefits of tool design to overcome some of the forces involved in turning and how they reduce hazards / risk and fatigue levels for the turner.

The tool shaft & handle is basically a simple lever with a cutting edge at the tip, the tool rest the fulcrum, and the basic equal and opposite forces thing to create the cut. Less cutting side tool overhang and more shaft + handle length equals more mechanical advantage (a simple lever) and less strength required hence less fatigue. More overhang requires more force from the turner and creates more risk as it pushes the tool shaft, handle and ferrule material and tool design properties to the max.

The presentation of the cutting edge (i.e. pitch, roll, yaw) also has a very significant influence on effort required, safety and desired outcomes.

Skew Chisels are manufactured from flat stock, Conventional SRG's and Continental Spindle Roughing Gouges are forged from flat stock and all have tangs, which can be a weakness if the tool is used inappropriately. Some SRG's such as the now discontinued P&N's are like a bowl gouge on steroids and are milled from solid stock and do not have the disadvantages of a tanged tool.

The "U" shaped profile of the conventional tanged SRG and Continental Spindle Roughing Gouges give the tool more inherent strength to cope with the forces and stresses of "interrupted cuts" and the tool overhang past the tool rest support. Tool overhang should always be kept to a practical minimum - for safety and to create less stress on tools. All tools have design limits and can present serious hazards when those limits are exceeded i.e. BREAK! I have seen some truly incredible examples of abused and broken tools.

Crocys advice re protecting sharpened and honed edges is excellent advice.

I highly recommend viewing the Alan Batty video on using skews - https://www.youtube.com/watch?v=KfeLAHQSbqk&vl=en and the excellent series of videos by his son Stuart Batty.

Examples of live & drive centres - the "safety drive centre" @ https://mcjing.com.au/categorybrowser.aspx?categoryid=77