Thoughts on Grinding a Gouge
Grinding jigs for gouges are good for novice or hobbyist turners who don’t have an overwhelming need to save time. I used the Wolverine jig for my spindle and bowl gouges until recently. I stopped using it as a rule mainly because I felt like it was hindering my production speed, because the setup time began to annoy me, and because the tightening mechanism was continuously coming loose. One day I went “cold turkey” and convinced myself not to reach for the jig when needing to grind a gouge. The value of that decision became apparent recently when an instructor started handing me tools to grind for the students in a recent workshop – I have to admit that it felt very good to have that kind of reinforcement. Anyway, the ability to grind freehand is very liberating and useful.
Obviously, freehand grinding takes practice and risks a fair amount of tool steel in the process. That said, the “fluteless” gouge (see Spindle Chisels with Specifications (Video #1 Request) ) I introduced several weeks ago on my blog is a wonderful tool to assist in developing freehand grinding skills for gouges because of its low cost. The tool steel I purchase is between $2-$7 depending on diameter with an additional cost of $2-$3 for a ferrule and handle.
A description of my method for freehand grinding a gouge –
(Text in red are corrections/updates I made to this thread after discovering an error on 12 NOV 11)
I hold the tool with the blade between the thumb and forefinger with my hand resting on the tool rest that is positioned somewhere in the 45-degree range (not overly important, but more comfortable if positioned above zero degrees). I grip the handle with the other hand closer to the ferrule than the end. I start by riding the heel of the gouge on the wheel then slowly lifting the handle until grinding just below the tip. I then slowly move the handle to the side while simultaneously rolling the tool with my fingers and handle hand, my body follows, while gently lifting the handle to keep the bevel riding. I move/roll the tool until I am just around the curve of the nose and then I begin to push up and across the wheel at an ~30-degree angle – I try not to over roll the tool. I’ve noticed that the angle I use is approximately 90 degrees minus the bevel angle (e.g., 90-35 = 55) from its upright starting position. There is a tendency to over roll (especially when in a hurry) to get the cutting edge on the stone resulting in an obtuse angle at the cutting edge that limits the tool’s ability to cut. Resist that temptation and maintain the aforementioned limit while moving the tool up and down the stone so that the blade is ground along the width of the bevel forming an even edge where the inside/top surface meets with the bevel. The final length of the wing is set by how far the tool is pushed up the wheel. After reaching the rear of the wing, move the tool in a reverse manner back through the nose and start the same process on the opposite side. This approach is repeated on each side until the sparks come over the edge indicating it is sharp (another sign of sharpness is the slight discoloration that occurs along the cutting edge). Strive for a consistently light touch with constant movement to get a smooth bevel with limited facets while thinking about letting the stone grind the bevel and not the tool edge. As a side note, I like to dip the tool nose in water periodically to keep it cool.
At about the seven minute mark in my initial video located on this blog ( A little spindle turning with the Tri-color Turners) (video link updated with site change 3/14/2020) you can view how I grind a “fluteless gouge” using the method just described.
I hope this description helps and makes sense:)
Regards,
Matt