More on Unicorn Profile

[Derek Cohen]

Winston, I don't have photos of planed boards to hand (although there are a lot of planed boards in the build articles), so I will describe a few features.

First off, I only work with hard woods. The softest wood I have is Tasmanian Oak, which is similar to White Oak. I posted pictures recently on Jacaranda.

Of relevance is that the West Australian woods respond differently to the USA woods I have worked a fair bit with: Hard Maple, Cherry, and Black Walnut. The US woods all have longish fibres, while the Australian woods have short fibres. What occurs with the Oz woods when they tear out is often subtle - there is a roughening of the surface, with a "grated" look like an abraded scab. There can be more common looking tearout as well, but it is not as extensive compared with the US woods. When Hard Maple tears out, for example, it is like a large splinter coming off. There is a deep gash in the wood. Much of the time the US woods do not tear out, and can be planed with low cutting angles .... but, then suddenly! Ouch! With the Oz woods, it is much more frequent, but not as dramatic. You learn to be planing for potential tearout all the time. If you are not closing down the chipbreaker, you plane with a high cutting angle. The though of planing with a common angle and no chipbreaker just does not compute.

Regards from Perth

Derek

[steven c newman]

Well pad is on my 6" grinder, now. Green stick has been used....two chisels have been "subjected" to this "method".....not at all happy with the results..they were actually dulled, edge profiles got changed...will try again when I get a bit of time....not a "happy camper" right now....

[Jerome Andrieux]

Winston, I don't have photos of planed boards to hand (although there are a lot of planed boards in the build articles), so I will describe a few features.

First off, I only work with hard woods. The softest wood I have is Tasmanian Oak, which is similar to White Oak. I posted pictures recently on Jacaranda.

Of relevance is that the West Australian woods respond differently to the USA woods I have worked a fair bit with: Hard Maple, Cherry, and Black Walnut. The US woods all have longish fibres, while the Australian woods have soft fibres. What occurs with the Oz woods when they tear out is often subtle - there is a roughening of the surface, with a "grated" look like an abraded scab. There can be more common looking tearout as well, but it is not as extensive compared with the US woods. When Hard Maple tears out, for example, it is like a large splinter coming off. There is a deep gash in the wood. Much of the time the US woods do not tear out, and can be planed with low cutting angles .... but, then suddenly! Ouch! With the Oz woods, it is much more frequent, but but as dramatic. You learn to be planing for potential tearout all the time. If you are not closing down the chipbreaker, you plane with a high cutting angle. The though of planing with a common angle and no chipbreaker just does not compute.

Regards from Perth

Derek

As a European, I see Australian wood just like any other "exotic" woods...: usually harder, heavier and more difficult to work with.

From chestnut to sorb, highly figured pieces are the only situation where using a BU plane becomes an issue. In my experience however, BU planes still requires more maintenance than BD, because of their particular wearing behavior on the back side of the bevel (back wear bevel? On the flat side that is). I guess this behavior is exacerbated in your WA woods.

[steven c newman]

Decided to "retire" that old Craftsman 6" dual wheel grinder...1950s model?....as I picked a better one up, today..
Friday Estate Sale, grinder.JPG
For....about...$10...
Friday Estate Sale, name plate, grinder.JPG
The wheels have no signs of even been used...will need to haul this heavy thing down to the shop...and switch it and the old Craftsman out....

I did not see any "pedestal", sitting at the Estate Sale today....Hopefully the "new" grinder fits where the old grinder did....

[Curt Putnam]

Steven,

From another beginner with the method .... The 6" grinder is almost certainly full speed which means a lighter touch and a shorter (time-wise) touch. David says that there is a short period of failed experiments required to "get it right." I am at the point of win some, lose some. A central point of the method is that raising a wire edge before buffing removes whatever has gone before and presents a clean slate to the buffer.

[Derek Cohen]

As a European, I see Australian wood just like any other "exotic" woods...: usually harder, heavier and more difficult to work with.

From chestnut to sorb, highly figured pieces are the only situation where using a BU plane becomes an issue. In my experience however, BU planes still requires more maintenance than BD, because of their particular wearing behavior on the back side of the bevel (back wear bevel? On the flat side that is). I guess this behavior is exacerbated in your WA woods.

Jerome, the wear bevel is essentially a non-issue in practice. I have never had a BU place stop cutting, or cut poorly, owing to a wear bevel. Part of the reason for this is that I ensure that the back of the blade is polished when I hone, and then I may strop it (the back ... you cannot strop the micro secondary bevel on the face) to extend the edge. An alternate method here is to use the Rule Trick (I do not as I just prefer to strop).

Regards from Perth

Derek

[Cliff Polubinsky]

I LOVE this procedure.

In less than 3 hours yesterday I sharpened 18 chisels, a combination of bench, paring and butt, PM-V11and white steel. A few were chipped so I had to start with coarser stones and work up to the 1000 stone. I found that I could tell when I had buffed properly when I saw the thin bright line along the edge and that I should recharge the wheel more often than I expected. I tested each chisel after sharpening and they all cut whisper thin shavings of maple.

If I'd used the way I had been sharpening I'd still have a good number of them to do today. Thanks to all that passed along the information.

Cliff

[Charles Guest]

https://www.youtube.com/watch?v=re_bp5Lp0To

[ken hatch]

https://www.youtube.com/watch?v=re_bp5Lp0To

Charles,

Good video and for folks that are un-aware of the technique should be very helpful. I don't use blunt chisels often but when needed like adjusting the bed of a wood stock plane they are very useful.

ken

[Jerome Andrieux]

Jerome, the wear bevel is essentially a non-issue in practice. I have never had a BU place stop cutting, or cut poorly, owing to a wear bevel. Part of the reason for this is that I ensure that the back of the blade is polished when I hone, and then I may strop it (the back ... you cannot strop the micro secondary bevel on the face) to extend the edge. An alternate method here is to use the Rule Trick (I do not as I just prefer to strop).

If follow the same process and get good results. I understand that they provide great value considering the wood you work with, honed at a high angle.

I find BU blades to be more maintenance and poorer ergonomics when it comes to sharpening. For one thing, BU blades are thick but short and I have large hands. Not to mention that when chipping happens, the thickness of the blade implies a lot of grinding.

[Derek Cohen]

If follow the same process and get good results. I understand that they provide great value considering the wood you work with, honed at a high angle.

I find BU blades to be more maintenance and poorer ergonomics when it comes to sharpening. For one thing, BU blades are thick but short and I have large hands. Not to mention that when chipping happens, the thickness of the blade implies a lot of grinding.

Jerome, I am not trying to sell you on BU planes (I use BD planes far more), however there are some factors here that are non-issues in my world. By-the-way, I have large hands as well.

Sharpening is never recommended to be on a full bevel, unless used on a shooting board at 25 degrees on a hollow grind. For all other bench plane use, there is a secondary bevel, and this is added with a honing guide to assure that the correct angle is obtained. This is especially important if you wish to add a camber to the blade. The size of one's hands is irrelevant. And chipping is no more a factor than for any other blade - actually, probably less for BU planes. The thickness is never an issue if you are hollow grinding.

Regards from Perth

Derek

[Jim Koepke]

The thickness is never an issue if you are hollow grinding.

This is true for many. Many others may not be set up to hollow grind.

jtk

[Eric Rathhaus]

Hi Ken - is he essentially creating a scraper with a long handle? Seems like that burr is like the hook edge of a scraper.

[ken hatch]

Hi Ken - is he essentially creating a scraper with a long handle? Seems like that burr is like the hook edge of a scraper.

Eric,

That is how it acts. If you use or make wood stock planes they are lifesavers. I've a few, don't use often but when you need one nothing else works as well.

ken

[Jim Koepke]

Look at the video again he holds the chisel and gouge upside down on the grinder. Afterword he mentions the burr and says it has nothing to do with the working of what is essentially a 90º bevel.

The blunt chisel works more like a float with only one tooth.

This one might not work well with a unicorn profile.

jtk