Wood carvings by Maura

       sharpening             

 A sharp tool is a wonderful tool and a point of pride. However, sharpening a knife can be a tough skill for

many to learn.

 

                       Safety

It is important to take safety into consideration when sharpening.  You are dealing with sharp edges, flying

grit and high speed revolving wheels.  Pay full attention to what you are doing.  Safety glasses are recommended.  Keep hands clear of all machinery and handle your tools with care.

There is a saying, that a dull knife has hurt more carvers than a sharp one ever will. A dull knife does not cut

 in the manner intended and is more prone to slipping.  A cut from a sharp knife will be a cleaner cut than from a dull one and will heal faster.

 

Sharpening supplies can include power sharpening systems, sharpening stones (natural and manmade), strops, honing wheels- leather, paper, felt or cloth (which you can attach to a hand drill, grinder  or drill press) and buffing compounds. There is even a method of sharpening which involves attaching various grits of sandpaper to a thick piece of glass or ceramic tile.

There are some very nice and easy to use sharpening systems on the market and some of them you will pay dearly for, but sharpening supplies do not need to be expensive.  A new carver should invest the time and energy into learning to sharpen, even before he learns to carve because if your blade is not sharp, it will make carving difficult and frustrate you  .  Sharpening is the one thing in carving that you will repeat thousands of times. Multiply that by the number of edged tools you own.

 

Sharpening for Dummies

Concepts you must grasp: 

bullet Grinding, whetting, honing and stropping are not the same.
bullet  They are different steps in producing a sharp edge.
bullet 
bullet  The entire sharpening process involves starting with a grainy surface and then stepping down to less
bullet grainy surfaces until you reach a virtually smooth surface. 
bullet 
bullet Compound is a chalky substance, which will add a bit of grit to the surface you are using.  Generally,
bullet the darker the compound, the more grit the compound will contain. 
bullet 
bullet The current shape the blade is in will determine what grit you need to start at.  Grinding should only
bullet be done when the blade is chipped, malformed or extremely dull.

 

 

  If you look at the edge of your knife, chisel or gouge, you will see a bevel.  The bevel is the angle which is on the edge of the blade, usually this bevel is between 10 and 25 degrees. bevels of 10-20 degrees are used for softer woods, 15-25 degrees for carving harder woods.  Some tools will have 1 bevel, others will have 1 on each side and both bevels must be sharpened. when sharpening a tool with only one bevel, first you must dress the back (the side without a bevel) by keeping the blade perfectly flat against the stone, using constant movement.   When the back of the blade is perfectly flat you can proceed to sharpen the bevel or bevels.

Sharpening Grits

Grit, very simply is the number of hard particles per square inch of surface

36-250, Very Course........................Regrinding of damaged edges

250-400, Course................................Removal of nicks and slight damage

400-1000, Medium.....First stage of obtaining a fine edge, final stage for rough work

1000-4000, Fine........Second stage for fine edge, final stage for general purpose

4000-8000, Very/Super Fine..............Final stage for fine edge on carving chisels

 

Higher grits of sand paper can be purchased at auto supply stores, higher grit wheels and stones can be purchased at specialty stores that deal with woodworking or carving.

Direction

 

Using any hard sharpening stone (manual or mechanical), you are going to line your chisel up on the stone so that the bevel is laying flat against the stone.  then you will use a slight downward pressure and holding the blade with the bevel correctly angled against the stone, constantly move the edge of the chisel or knife across it.  For hand and machine grinding, you will push the blade into the stone as if trying to slice off a very thin sliver, repeat this movement over and over.  For machine whetting, the blade is not being pushed into the stone, but will ride on top of the stone with the wheel revolving away from you at the top of the wheel.  Hand whetting will require that you pull the blade back toward you over the stone.    When using a mechanical sharpener, it is important that you monitor the edge of your tool making sure that you don't let the edge become overly hot.  You can burn the edge of your blade which will destroy the temper (hardness) of the edge.  This can be avoided by removing the tool from the stone and letting it cool a bit before applying it again.  If you do burn an edge (you will see a discoloration of blue, black and brown), simply sharpen it  again until you remove all the discolored metal.  You can also use water on the stone to help keep the temperature caused by the friction, down.  Some stones say to use oil but I find water works just as well or better and does not gunk up the stone.

 

As you sharpen,  a small burr (very thin metal particles clinging to the edge of the blade) will start to form.  A blade is sharp when the burr has formed along the entire edge of the tool or when you hold the edge up to a light and can not get a reflection off the tip when looking directly into the blade.  

After you have sharpened your blade you will proceed to hone your blade.  Honing is done on a softer material than stone.  I have seen many things used, from cloth or felt wheels, to leather strops and pieces of flat cardboard.  I prefer to use a cloth wheel which is mounted into my drill press.  You apply a buffing or honing compound to the surface of the wheel and holding the blade against the wheel, with the wheel spinning away from the tip, proceed to buff the tip.  Buff until you have removed the entire burr that formed in the sharpening process and until you have achieved a mirror finish on your blade.

If a blade is properly sharpened, you will not need to sharpen again for a long time, unless you have chipped the blade. I find that chipping of the blade is mostly caused by dropping a tool, tools banging against each other in your toolbox, a tool rolling off the bench or the improper use of the blade as in prying wood off, rather than cutting into it.  A little care taken to see that these "accidents" don't happen will go along way in saving you from having to sharpen.  Honing the blade often during your carving process will keep the blade sharp.

Sharpening rounded edges as on a gouge takes some time to get the feel for, but is done in the same manner as a straight edge.  You rock the edge against the stone as you are sharpening so that the entire edge makes contact with the stone.  Take care to keep the right angle of the bevel flat against the stone.

When sharpening a v-tool, keep in mind that there are three separate bevels to this tool, two main blades and a small edge in the center.  Each edge must be sharpened independently.

The final step should be to polish the entire bevel and back of the blade on a soft cotton or cloth wheel.  If you are using premium steels, you should be able to attain a mirror finish.  This is important.  Any irregularity in the surface of the bevel will translate into scratches in your carving.

There are different methods for determining if a tool is sharp.  Some like to see if they can shave the hair on their arms and others drag the cutting edge over a fingernail.  It will slide smoothly with no drag when sharp.  The method that I prefer is to stand underneath a bright light, a bare bulb works best.  Look directly down into the cutting edge.  If any light reflects off the edge, it is not sharp yet.

 

THE NO NONSENSE JOOLTOOL REVIEW------

 The purpose of buying the Jooltool was to provide a carving class with an all purpose sharpening system that everyone could learn to use properly and easily. I was originally looking at the Burke sytem and other vertical wheel sharpening systems but went with a reccomendation from the vendor.  I was a bit skeptical at first but agreed to try this new horizontal abrasive system.

 My expectations:  a fast, easy way to sharpen knives, gouges and other edged tools.

 I opened the box and unpacked the jool tool and all the accessories.  It came with one backer plastic, lots of different grits 3m sand paper appliques(80 grit ceramic disk 1 - 120 grit ceramic disk 1-220 grit ceramic disk 1- A-5 micron Ninja disk 1 - Red (A-20 Micron) Ninja Disc 1 - Blue (A-10 Micron) Ninja Disc 1 - Green (A-35 Micron)), a buffer which needed to go onto the backer, 2 cloth buffingwheels and 2 hunks of white rouge and a dvd.  I then took the main unit out of the box.  The outer housing was a bright white and red plastic, which looked cool yet cheap at the same time.    Its footprint is 8" round so it doesn't take up much space.  I then popped the jooltool dvd into my player to learn what this new toy could do.  It promised to be a revolution in sharpening systems and showed  a wide variety of edged tools and bits being sharpened quite easily.  Would it work for me?  Only one way to find out.....now for the fun part.

 The SET UP- The unit needed to be mounted onto a piece of plywood or benchtop in order to stabilize it.  It comes with two screw holes to make this easy to do. Then onto setting up a disk. You simply peel and stick a sandpaper disk onto a plastic backer disk, you then screw this assembly onto the tapered spindle until hand tightened.  The abrasive surface is mounted down. You reach around and turn the variable speed unit on. You take your tool to be sharpened and approach it from underneath the spinning abrasive.  The unique cut of the 3m pads allows you to see through and watch as your tool comes in contact with the abrasive.

What I liked about the system:     Its bright plastic outer housing is pleasant and inviting as a toy would be.  It seems less intimidating to approach, especially for the women who may shy away from shop machinery.  The set up was quick and easy.  There is a slight learning curve for those who are new to sharpening and a retraining of the mindset for those used to vertical sharpening systems. It requires a slight bit of practice to bring the tool up properly to the abrasice pad but once this is mastered it is quite easiy to follow the bevel of the tool.   it also comes with some heavy duty diamond abrasive pads which make grinding simple. It is able to sharpen any edged tool and/or bit that will fit into it.  it can be used on a variety of materials, metals, woods, ceramics and can be used for sanding smaller objects. The see through capability and the bottom up approach work together well and allow you to view the edge of your tool as you sharpen although the visibility is only as good as the overhead lighting in your work area.  I do like that the unit is on a slight tilt towards the user, making it more comfortable to use. It did sharpen quite well, fast and efficiently.  I started with a coarse grit and stepped down through a medium and fine disk and followed that up with a buffing pad with rouge.  each step took less than 30 seconds.  Changing the backer disks was quick and simple(2-3 seconds) and required no tools.  It works in a standard outlet.  It takes up very little bench space.  It comes with lots of bright colored cool accessories and disks.  3M produces the sanding disks and they seem to be a high quality product.  The design of the disks allows cool air to circulate up and around the abrasive disk and tool being sharpened to lessen the possibility of burning or losing the temper of the tool being worked on.  I did find that my steel stayed relatively cool.  The unit was quite quiet and smooth sounding.  There were no complicated controls to learn, just one variable speed power knob.  There is an easy to access fuse panel.  The unit creates very little dust or dirt as rouge is used only in the final polishing stage. It does have a hood around it to keep any debris from flying away. There is a vacuum connector built in if you wanted to do some wood sanding or other dust/dirt producing application. It easily sharpened and polished various gouges and chisels and  it removes the hollow grind that is inevitable with a vertical wheel system. 

 The things I didn't like:  The price of the unit $279, the price of accessories $16-40 each. It really requires more items in its standard package. It may price itself out of the market of the average hobbiest.  In order to make good use of this machine, more than one plastic backer is required but thats all that comes with it.  I had the good sense to preorder an additional 3 set of plastic backers (around $38) to give me a total of 4 disks on which to apply the sharpening disks and buffing pads.  Honestly, I could have used another 3 at least. The price of extra abrasive pads varies according to the grit but are a minimum of $16.  All in all, the initial outlay for this unit was approx.$400.  Switching between the different grits if you only have one plastic backer disks seems like it would be a pain in the butt as you will have to peel one off and replace it with another.  I can't imagine how many times you can do this before they no longer stick or until you tear the pad.

Even though I said I liked the red and white outer housing I also didn't like it because it looks a bit cheap and flimsy, and men who are used to heavy duty looking machines in their shops will be taken aback by its appearence. 

Care needs to be taken when sharpening double sided knifes as a rotation problem may cause the blade to catch the edge of the abrasive pad, it can kick the knife back and/or chew up the pad.

One thing that particularly irked me was to have the variable power switch set on the back of the machine so that you had to reach around it to turn it on or off and to adjust the speed. 

One other thing I didn't like is that there is no where on or in the unit to store all of the accessories that should be at hand.

 My conclusion:  All in all, I would give the Jooltool a 4.3 rating out of 5.  It did meet my sharpening expectations. It is a nifty, lightweight, possibly portable sharpening system. You cannot beat seeing the surface of the blade that you are sharpening. It is easy to setup, easy to understand and use. It is highly efficient and puts a nice edge on a carving tool but as with every other sharpening system, the skill of the user has to be taken into consideration also.  It is quiet, relatively clean and takes up little space.  It may justify its price by its promised longevity and durability but that remains to be seen. Also, as my unit is new, I cannot attest to the life of any sanding disks. I sharpened roughly 10 or so tools and there doesn't look to be much wear on them. If you are a tool junky, like myself, it is a really cool toy and I would  imagine that as more people acquire these machines, more and more accessories will become available as happened with the dremel.  It looks promising for the future. 

My recommendations:   The on/off switch needs to be moved for both safety and comfort reasons.  Also for safety reasons, it should be advised that double edged knives should only be sharpened at higher speeds.  it is too easy to catch the blade when the pads are spinning at the slower speeds. The basic package needs to be beefed up to include more of the plastic backer disks.  And if at all possible there needs to be a built in light or a fitting added which would allow a light to be added in some way.  While understanding that the system and its accessories are new to the market, perhaps as more are sold, something could be done to lower the cost of the accessories. 

 

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Maura Macaluso
Staten Island, NY
917-494-0008

made in the USA

©2005 Carvin' in NYC