Double grind - lets talk chisels

[DaveTTC]

I have been interested in a ciuple of chisel threads currently. Some well thought out input.

Recently i have seen some Americans using a double grind on their chisels.

1) They have a micro bevel (done free hand without using a rest)

2) the major grind also done free hand is a convex grind

One of the guys who does this promotes shear cutting i think it was. He starts sanding at about 400.

a) My question is others views of this?
b) Have / would you try this?
c) As mentioned by Hughie in another thread .... aussie timbers are hard. Would this work on our timbers?
d) an observation for comment rather than a question. It seems the grinds are not particularly repeatable.

I will try and access my youtube library and post a link to one of these guys

I hope this link works

https://youtu.be/YYlK_njna_M

Thanks in advance

Dave TTC
Turning Wood Into Art

[Mobyturns]

On my bowl & spindle gouges I have a single grind & relieve the "heel" of the grind so bowl gouges do not bruise timber on smaller bowl diameters.

If you hone tools that have a hollow or concave grind (6" or 8" grinder) then you are effectively creating a second micro bevel anyway.

My opinion is that the shorter the length of the bevel means there is less "bevel support" but a tool cannot cut if it is "rubbing the bevel" which is actually accentuated with a secondary micro bevel. When we use the term "rubbing the bevel" we are actually running slightly off the bevel to have the edge cut. Shortening the "primary" bevel length means the bevel is "flatter" and not so concave.

[DaveTTC]

I share your concerns with regards a short bevel thus my questions.

Out a link in first post now to youtube. There are 4 in total by this guy but this one i think soends the most time on grinding the bevel etc.

He is talented

Dave TTC
Turning Wood Into Art

[Mobyturns]

I share your concerns with regards a short bevel thus my questions.

Out a link in first post now to youtube. There are 4 in total by this guy but this one i think soends the most time on grinding the bevel etc.

He is talented

Dave TTC
Turning Wood Into Art

I have only just glossed over the clip will look at it in more depth later. A few things there that I would not do or recommend but its good to see a range of views.

[dai sensei]

Like Mobyturns I grind the heal on all my bowl and spindle gouges for relief, but the main bevel is still a decent size. I do have a few Cindy Drozda 10V gouges (http://www.cindydrozda.com/html/Tool_Info.html) with micro bevels that enable access to cut small details. You do have to be careful with them, as you normally are for those small finials and hollow jobs.

[powderpost]

The video mentioned in the first post shows some interesting concepts. I couldn't quite work out what his objective was, admittedly I didn't watch the whole story. To make a "V" cut I use a skew, which is in my opinion is the most efficient tool for the job. I have a number of skew chisels sharpened with a longer bevel that will give me a very sharp edge best suited for soft woods. If I am cutting hard timber I reduce the length of the bevel to produce a thicker edge but not quite so sharp. The shorter bevel, I find, is difficult to get good definition between two or more close beads. The argument that bevels need to be consistent and repeatable flies in the face of all that.


The early Robert Sorby chisels had sharp corners, these were rounded on all four corners. My skews are ground when needed on an aluminium oxide wheel and honed on a water stone, but then I am a traditionalist when it comes to hand tools. Over a long period of time, a lot of tradesmen have tried all sorts of things and worked out an efficient method of doing things. I can not see any real need to deviate from those methods. Over the past few years, there has been significant development in the quality of steels, but that is another argument. There also has been a proliferation of "new" tools that will solve that problem miraculously. Plus many "signature" tools promoted by recognized wood turners, most of these are necessary for the average weekend turner, in my opinion.

My spindle gouges are ground and sharpened traditionally, I see no need to change that. Bowl gouges are a bit different, they all have a secondary bevel, to make it easier to work inside bowls both large and small.

The bottom line is that any person can take almost any tool, create a edge, and with persistence and time, produce an acceptable shape.... eventually. Traditional methods have stood the test of time and are still efficient.

Jim

[DaveTTC]

Thanks for your comnents so far. Hope more to come. We all differ but i love to hear the opinions of others. Glean a little here and glean a little there and i may just become a better turner.


Dave TTC
Turning Wood Into Art

[Paul39]

There are many paths to the same place.

Each of us will eventually find what is comfortable and efficient to do whatever turning we do.

I think that 25 - 50 hours with any one tool in front of the lathe is worth a whole bucket full of miracle Famous Turner endorsed tools that promise to make us proficient turners with no catches.

A couple of years ago I was having trouble with spectacular catches and wondrous unintended spirals with the skew. / Retired and others encouraged me to keep persisting. Practice, practice, practice, was what everyone said.

I hate to practice just for the sake of practice, So I made big fat tool handles for my large arthritic hands.

After about 25 hours and a slew of tool handles the catches and spirals went away and I now make a tool handle for entertainment and as a diversion from making bowls.

I had, and have, a selection of skews, Henry Taylor, Sears Craftsman, and mystery metal with crude home made handles.

I will buy a box full of turning tools sometimes to get one or two that I want. At around $5 each I'm not breaking the bank.

The one I used most and provided the best result when I was having my agonizing learning process was a 3/4 inch carbon steel Chinese skew with a too small handle and razor sharp corners. I quickly rounded off the corners.

It came from one of the new price 8 for $20 sets.

I still use it if I am turning split timber with bark on and who knows what embedded in the tree. Get dull, hit a nail, zip zip on the grinder, back to cutting.

I used the toe a lot on the ends and making the reduced diameter for the ferrule and in sharpening got a curved end. That worked very well for planing cuts, so now I have one of my big HSS skews with a curved end.