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Raffan's asymmetrical gouge grind video

S

Steve Tiedman

Joined
Oct 25, 2020
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I have one of Tomislav Tomasic's asymmetric grind bowl gouges coming in the mail (it's stuck in NY USPS - probably customs). His asymmetric grind is based on Richard's grind. Once I get it and try it out, I'll post what I think.
 
Trent Bosch uses a slightly different symmetrical ground gouge (1/2 bar) for finishing cuts on bowls.
Sort of Ellsworth wing on the left side and a nearly traditional steep bevel on the right side.

This tool makes flute up finish cuts on the outside with the steep wing and flute up finish cuts on the inside with the Ellsworth like wing on the left side.
 
Early on I had an asymmetrical grind. It had about an 9nch and half grind on the left wing. I was turning my hand mirrors and a pull cut made the most sense when trying to get a nice smooth convex cut across the face of the mirror. Years later I still do the same cut but with a wing that's about 5/8" I now don't use an asymmetric grind. I simply grind both wings the same. I now use the right side of the gouge for pull cuts or shear scraping some times and it doesn't take any longer to grind it.
 
I have yet to try this tool. As near as I can tell, one wing is for outsides of bowls, and the other is for the insides. Me, I do not use a swept back gouge at all any more. Trent Bosch commented at the latest Oregon Woodturning symposium that the swept back gouge is a "jack of all trades" tool, and my thoughts were, jack of all trades but master of none.... I use the 40/40 and BOB tools for my bowls.

robo hippy
 
I’ve tried it, it works as advertised, but doesnt fit my preferred method. Small % of bowls have a way of not running true when put in a chuck, so I dont finish the OD until then, with a slicing cut using the right wing, as well as shear scraping. I also like to use both wings in slicing cuts on larger spindle work.
 
Just received Tomi’s asymmetric grind bowl gouge. Tried it out on some really dry glued up boards (making a bowl). Definitely need practice with it. Cut really nice on the outside. I had difficulties on the inside. I’ll keep trying it and if it doesn’t work out, I can always regrind it into a grind I’m more familiar.
IMG_9007.jpeg
 
I think the trick with an asymmetric grind is sort of a need to develop muscle memory for two different grinds - When I first saw Raffan's video on that grind I was intrigued by it - By that time I had a older 1/2" bowl gouge that I had a "sort of" 40/40 grind (or as close to it as Varigrind can make) and hardly ever used it except on some inside bowl cuts , so I experimented with a freehand asymmetric grind like Raffan showed in his video, and it worked quite well - However I noted that the technique to make cuts was different depending on which wing you were cutting with so on the "short wing" side I would use the same "memory" of using the 40/40 , while on the other wing I could easily utilize the features of the swept back ellsworth-style grind I have on most of my bowl gouges.

In other words, it needs a bit of practice but familiarity with using different grinds can be helpful because there's subtle differences in tool handling and control between them... at least that's my take on it. (Opinions are worth the paper they're written on)
 
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