My old Echo brand 8-inch bread knife has seen better days. I've posted about it before here in this forum. The conventional wisdom (we learned this from Jeff) is that these knives that are scalloped on only one side are sharpened by grinding the flat side. Well, I had done this so many times to this old Echo knife that it just wasn't working any more. Ken S and others encouraged me to take a round file, or a wooden dowel and diamond paste, and grind away at the scallops. Not having any diamond paste on hand I decided to glue some wet-o-dry sand paper to a wooden dowel and give that a go. The sand paper quickly wore out and then it tore.
Recently I purchased a Victorinox as a replacement. When I showed it to my wife she commented that we'd had that old Echo knife since before we were married. So I figured I'd take it to my local hardware store. They have a guy from Greater Houston Sharpening come and pick up stuff on Mondays, then return it sharpened the next Monday. They charge $3 plus $1 per inch, so that's $11 for this knife. They have a warning on their flyer that the depth of the scallops gets reduced with each sharpening, so I had my doubts. I figured that maybe they too only grind steel off the flat side. One way to find out is to give it a try.
I picked it up last week, bought a loaf of bread to celebrate, and headed home to surprise my wife. I was immediately disappointed by the first slice. Tried my new Victorinox and it cut much much better. Out to the shop and a look with the magnifier revealed that they had indeed ground on only the flat side, and their grinding marks didn't reach all the way to the edge! So I called the sharpening service and they had me leave it at the hardware store. Yesterday was Monday and I got a call from Mike at Greater Houston Sharpening. He said my knife was waiting at the hardware store to be returned to me with a refund of my $11. He's a really nice guy and explained that they hire teenagers and family members to sharpen, that he does the final inspection, and that somehow this one got by him.
I've talked to Mike before about sharpening in general and Tormeks in particular. He's sharpened a few of my table saw blades and a hand saw or two over the years. He confirmed that Jeff's method of grinding only the flat side is the correct method. He said that there's a new machine that costs $5000 that sharpens three types of scalloped edges, but he declined to buy it.
I asked about the wooden dowel method and told him that a 1/2 inch dowel matched the curvature of the scallops pretty well. He said that in that case you want to use something smaller so you can grind at the valley of the scallop and then roll the tool out towards the tips of the scallops as you sharpen. He recommended a round file made for metal and said that that Echo knife will have very hard steel.
He also mentioned that the Nicholson files are not being made any more, and that the alternatives from China are a waste of money. So, when I pick up my knife at the hardware store I'll be looking for a round Nicholson file. 3/8 inch.
Herman, in this country, many knife sharpeners do not accept serrated knifes at all.
For my serrated bread knife I use diamond rod sharpener. One side of the sharpener is tapered rod, so you can select the appropriate segment, which corresponds to your serration size. I use the marker to delimit the part of the tapered rod, which should be involved in moving the sharpener back and forth for each serration. I also colour with a marker the bevel of each serration to see where my grinding occurs. With this care I believe the knife may survive functional for the next generation. :)
Jan
P.S.: Diamond files may be used with a back and forth motion without damaging the file, but keeping in mind the burr formation, it is better to apply the pressure only during the forth motion.
Excellent topic, Herman. Jan, your response was excellent, also. This topic hits many of the hot buttons of what is wrong with sharpening today.
Eleven US dollars strikes me as a fair price for sharpening a scalloped bread knife, providing the job is class A and done carefully by an experience sharpener. if the family member hired to do the job was a retired or moonlighting machinist, that would seem fine to me. If the teenager was an outstanding industrial art student majoring in the machinist trade, that would be fine, too. However, I doubt that was the case. Nothing personal against your friend, Herman, but the work was shoddy.
My opinions on sharpening scalloped blades are well known. I believe that grinding the back surface, although it is expedient, is not the proper way to sharpen a knife. Lee Valley and other places sell adhesive back fine grit abrasive paper especially designed for this kind of work. I don't believe ordinary wet and dry is up to the task. The adhesive paper I used did not tear. I used it with a 1/4" (6mm) dowel and only on the push stroke. Jan is right about burrs.
I have not yet tried it, however, I believe the diamond paste may be an improvement over the adhesive paper. My bread knife needs to be sharpened again; I will try the diamond paste and report.
I have read good reports about Grobet files, made in Switzerland. (lee Valley sells them.) Apparently they are of the high quality made famous by Nicholson for over a century before its decline. Too bad; they made fine products before they cheaped out.
Unfortunately, knife manufacturers seem more obsessed with their knives not staining than with how well they can be sharpened. The old high carbon knives worked very well if they were maintained. Now everything is stainless.
I think the smaller diameter dowels (1/4") are necessary to preserve the points of the scallops. With wider dowels the points would gradually be eliminated.
Herman, I hope you will return to rejuvenating your old knife with a quarter inch dowel and diamond paste. Your neighborhood Woodcraft would carry the date. A diamond file, like Jan recommends would probably work even better, although at a higher cost.
Ken
http://www.leevalley.com/US/Wood/page.aspx?p=58754&cat=1,43072
http://www.leevalley.com/US/Wood/page.aspx?p=58754&cat=1,43072
At the risk of sounding like an infomercial, Lee Valley is having one of its periodic "free shipping with orders over forty dollars" which ends the end of today.
I've been getting superb results of late with a diamond tapered file sold by Trend over here. It's a 6 inch file with a handle, flat on one side and barrelled (half moon type convex radius) on the other both tapering to just less than a point. So far I've used it to touch up my tungsten carbide tipped table sw blade which was as blunt as you like (80 teeth) and it'd really brought that back from the brink. Also just to tickle the edge of both skew and bowl gouge.
I was truly amazed at its performance with the bowl gouge. Using gentle circular motions all the way round the elliptical bevel it created a stunning edge for the finishing cuts. What surprised me was how little pressure you have to apply to get it to cut. I guess that's the power of diamonds. I'm really impressed with the versatile little gadget and intend to try it on the gullets of my big bandsaw blades which go blunt after ripping green logs.
The tapered and radiused edge would be a good fit for scalloped knives I suspect though not tried it myself (I do it the lazy way and just grind the off side).
As far as I know Nicholson still makes good files, it's just that they're going out of business. I picked up a round one at the hardware store yesterday.
Do you think this would work better?
http://www.amazon.com/Columbia-River-Knife-Tool-VEFF1/dp/B0030IX772/ref=sr_1_6?ie=UTF8&qid=1429118663&sr=8-6&keywords=diamond+tapered+sharpening+rod
http://www.trend-uk.com/en/UK/productlist/3/328/diamond_files_and_steels.html
4th product down (6" tapered file) is the one I'm referring to.
Here are pictures of my sharpening progress. As you can see, I made a jig to keep the round (rat tail) file at the right angle as I filed away at the gullets. Then I used the Tormek to grind the flat side at a 20o angle. I had to remove a lot of steel to reach the tips. Then I used the leather honing wheel on the flat side and the scalloped side. On the scalloped side I placed each gullet on the edge of the honing wheel. I've yet to use the knife to slice a loaf of bread.
(http://i1291.photobucket.com/albums/b553/htrivilino/Bread%20Knife%201_zpsbaasxomq.jpg) (http://s1291.photobucket.com/user/htrivilino/media/Bread%20Knife%201_zpsbaasxomq.jpg.html)
(http://i1291.photobucket.com/albums/b553/htrivilino/Bread%20Knife%202_zpskjls4m6j.jpg) (http://s1291.photobucket.com/user/htrivilino/media/Bread%20Knife%202_zpskjls4m6j.jpg.html)
(http://i1291.photobucket.com/albums/b553/htrivilino/Bread%20Knife%203_zpszf3htnvf.jpg) (http://s1291.photobucket.com/user/htrivilino/media/Bread%20Knife%203_zpszf3htnvf.jpg.html)
be interesting to hear the result when you get chance. Looks a thorough method, I'm sure it will work well.
I wasn't happy with the result so I filed on the gullets some more. I followed this up with a cylindrical stone attachment on a rotary tool. Then I ground the flat side on the Tormek grindstone again, prepared fine, to remove the burrs. I also briefly passed the scalloped side over the grindstone at the same angle to form little chisel tips at the high points of the scallops. After honing on the leather wheel I got something that now works well.
I compare to the new Victorinox bread knife that I bought recently. The flat side of that blade is completely flat, no bevel. The scallops on the other side each have an identical cylindrical shape. The geometry couldn't be simpler. There are burrs on the flat side left from the grinding that was done at the factory to form the scallops. I suppose these burrs improve the cutting action when slicing bread.
I wonder why these knives don't cut through skin easily. I'd think that the sharpened tips would be dangerous, but they aren't.
sounds good Herman....if a little labour intensive perhaps. Talking of knoves that don't cut skin reminds of when I was recently in hospital with my youngest. He's the one with all the leg bone troubles. The nurses were cutting off an old plaster cast from his shin and the rotary blade tool (electric) was able to cut through the plaster like a knife through butter yet when placed on your skin it just tickled. She demo'd it on the palm of my hand....couldn't believe my eyes, it just couldn't cut me no matter what she did and yet plunged straight into the plaster like an industrial chopsaw. Amazing technology and I've no idea how they do that.
Quote from: Rob on April 18, 2015, 06:22:42 PM
sounds good Herman....if a little labour intensive perhaps.
Yes, and a rather bold experiment, too. I could have easily ruined a knife doing this to it. But really, I figure that since I'd already given it to a reputable pro who couldn't do it, I had nothing to lose. To be honest, it now looks a bit like a key hole saw. I could probably use it to cut drywall. ???
Underlying form trumps superficial beauty in my view. If it's fit for purpose, who cares what it looks like ;D
Almost all of my Nicholson files are older and were purchased as "old new stock" or used. They all have "Made in USA" stamped on them. I am not opposed to purchasing products made elsewhere, as long as the quality is good. With Nicholson, I have read reports that the quality has slipped since moving production overseas.
One big problem with hardware stores is that they are usually "bastard cut" (a perfectly acceptable term). Over the years the number of cuts has diminished to three, bastard, second cut, and smooth. Bastard cut is the coarsest cut. This is designed for quick removal of soft steel. A good industrial supply store will have all three grades, as well as a much larger variety of files. Second cut and smooth work much better with harder steels and leave a smoother finish.
Files are essential tools. Every shop should have at least a bare minimum a set of three mill files, one of each coarseness and all properly handled. The inexpensive Nicholson red plastic handles serve quite well.
Ken
The round file I used to sharpen this bread knife is bastard. I could tell right away that it was far too coarse for the application.
Quote from: Ken S on April 19, 2015, 02:26:19 PM
Over the years the number of cuts has diminished to three, bastard, second cut, and smooth. Bastard cut is the coarsest cut. This is designed for quick removal of soft steel. A good industrial supply store will have all three grades, as well as a much larger variety of files. Second cut and smooth work much better with harder steels and leave a smoother finish.
To what does the term "mill file" refer?
Quote from: Herman Trivilino on April 19, 2015, 08:34:37 PM
To what does the term "mill file" refer?
Wikipedia has the following definition: Mill files are rectangular in cross section and taper slightly in both width and thickness from tang to end. They are all single-cut.
Jan
I don't know the origin of the name , mill files. I prefer the single cut over double cut files. Double cut files remove a lot of metal quickly. Single cut files cut slower, but I like the slower, more controlled cutting.
In addition to bastard cut, second cut, and smooth being different "grits", the same name "grits" become more coarse as the files get longer. An eight inch mill file will be more coarse than the same grit in six inches and less coarse than the same file in ten inch length. I have sets of files in four, six, eight and ten inch lengths. They are not expensive and having a choice is often useful. A set of three mill files in eight inch length is a good start. Put all files in handles and keep them handy.
Quote from: Ken S on April 19, 2015, 09:46:18 PM
I don't know the origin of the name , mill files.
My daring explanation is that the name
mill file originated as a name for a file which was used for jointing the teeth of
mill saw.
Jan
I believe you are correct, Jan.
Ken
Finally!!!!
I sharpened my bread knife today using the diamond paste for the first time. As hoped, it went very well.The one micron paste was surprisingly fast cutting. I cut a length of quarter inch dowel long enough to easily fit in a gallon plastic zip lock bag. I rubbed a bit of the paste into the one end of the dowel for about half the length.
I hand held the knife and dowel and gave six push strokes to each scallop. The knife was not in terrible shape; it was just dull. Six strokes revitalized the edge. The process took a leisurely five or ten minutes, including sawing the dowel. In the words of Herman's fellow Texan, it was "kindler and gentler". A very small amount of steel was removed. The sharpening was quiet. I did it at the dinette table. I did not need to touch the back side of the knife. Clean up was putting the dowel back into that plastic bag and washing the knife.
For someone doing a lot of this kind of sharpening, I believe Rob's diamond file is the best choice. For me, with one bread knife, the simple diamond paste worked very well. The adhesive micro abrasive paper worked well, also, Of the two, I prefer the diamond paste and would continue to recommend it.
The diamond paste is also available in three and six micron sizes. The paste works well and is useful for many things.
Ken
Quote from: Ken S on April 21, 2015, 05:15:54 PM
In the words of Herman's fellow Texan, it was "kindler and gentler".
Actually, a fellow Houstonian. He can often be seen at the Astros games.
QuoteThe diamond paste is also available in three and six micron sizes. The paste works well and is useful for many things.
I would be interested to see how it performs on the Tormek leather honing wheel.
sounds amazing...I've never tried the paste. It would be useful in any situation where you had to custom build the profile of the abrading tool to fit whatever it was you needed sharpening since the paste has no shape and can just be "appended" to whatever profile you need. In your case a 1/4" dowel was good enough for the bread knife job.
What I'm starting to think about is a custom fit (I would likely turn it) dowel or maybe cone of some sort that would perfectly match the gullets of any given bandsaw blade. I quite regularly use a wide 1.3 tpi 1" wide ripper blade for green logs when making my own turning blanks and green wood is a pig for blunting bandsaw blades due to the nasties that hide in the bark, grit, dirt etc all take their revenge on the blade. They're not cheap to replace and can stand a few sharpenings before being rubbish but they're not easy to do.
I bought that diamond taper file for exactly that job. Other folk have used a dremel with a particular grinding stone and various other methods. It occurs to me that I could turn an exact fit for that blades gullet size and then just smother it in that paste??? One could turn different cylinders or cones calibrated for each different bandsaw blade you use. For me that would be 3. Worth a try?
Rob,
Check out:
http://www.woodturningvideosplus.com/resharpen-bandsaw-blades.html
That would help out with more serious dings.
Of course there are machines specialized for the job. I saw an attachment to go on a chainsaw chain grinder sometime back.
That's great....thanks Elden. I must say I thought I'd seen them all out there in web land but not come across that one before.
This one
https://www.youtube.com/watch?v=UygEQ-079Ws
is frequently recommended by my blade guy (company called Tuffsaws here in the UK) but it does of course require you to remove the blade. What's appealing about the dremel or hand file technique is that it remains on the bandsaw. Much less downtime.
I've tried my ripper blades before with a sanding disc in the dremel but not the cut off disc. I'll give it a go :-)
Herman,
I have wondered the same thing about using diamond paste with the leather honing wheel. My gut feeling, untested, is that it might very well, but not inexpensively. It would be worth a try.
Rob,
I bought a pack of bamboo skewers at my local grocery. My original intended use was for pegs for mortises. They are round and about 1/8" (3mm) in diameter. I think they would work well with diamond paste for sharpening bandsaw blades.
I would like to see what a good turner could do. I hope you will give it a go, Rob. You would have the advantage of choice in shape, diameter and species of wood.
Elden,
Diamond paste comes in 1,3 and 6 micron grits. For the nasty nicks, a dowel with one of the coarser grits might do the trick. A file would be good to have in reserve, too.
Using the dowel and paste approach on a bandsaw blade would be an almost silent and peaceful way to work.
Ken
Interesting video Rob.
True Ken. Never have tried sharpening one. I don't use it often. Seems like I generally will get a kink in mine cutting pvc pipe or such. I will have to give it a try. Like the guy in Rob' s video, I am sure I would find out it pays to sharpen a new one.
Quote from: Ken S on April 21, 2015, 10:15:03 PM
I bought a pack of bamboo skewers at my local grocery. My original intended use was for pegs for mortises. They are round and about 1/8" (3mm) in diameter. I think they would work well with diamond paste for sharpening bandsaw blades.
As would chop sticks for a bread knife, in case one didn't have a scrap piece of dowel about. They have a cone at the end which would be nice for smaller gullets.
Rob, Your three teeth one inch wide ripper blades sound like a good candidate for sharpening. How long are the blades? (This is one instance when I wish I had not added the riser to my Dalta bandsaw. The riser translates into about an extra foot of blade to sharpen.
Elden, I think I will limit myself to sharpening the 3tpi, half inch blades. The 10tpi blade is a lot of teeth! It does a nice job on aluminum (including Tormek jigs) (For those of you who are thinking of slicing the grinding wheels, I have some slices of the Torlock platform. I should recycle them.)
Herman, clever idea about using chop sticks.
I cut a slice of gutsy multigrain bread with my newly sharpened bread knife. It was sweet. Very little effort and a nice, clean cut. i am sold on the diamond paste.
Ken
Gutsy multi-grain bread....lashings of butter....making me hungry ken :-)
My banana bread is gutsy. Lots of nuts! No butter needed.
Oh stop it....I love banana bread and I'm trying to lose weight!!!!
Herman raised the possibility of using diamond paste with the leather honing wheel. This has interesting possibilities, and possibly pitfalls. DMT makes diamond paste in three grits, 1,3, and 6 micron. I have only tried the 1micron paste. It certainly leaves a nice polish, its intended purpose. It also seemed to cut quickly for such a fine abrasive. Used with a dowel, or as intended, with a piece of MDF or hardwood, it works very well. I don't know how it would work with the leather honing wheel, or how long either the paste of the wheel itself would last used this way. If, by chance, it worked extremely well for a very short period of time and destroyed the leather honing wheel, it would not be cost efficient.
I have never thought of the Tormek as my only piece of sharpening equipment. I still have my oil and water stones, although they are hardly ever used since purchasing the Tormek. My dry grinder is still available, but almost never used. My files continue to get regular use for many tasks. I have a set of diamond hones which are quick and convenient for small jobs. After experiencing such success with my simple dowel and diamond paste with my bread knife, I can't imagine trying to sharpen it with the Tormek. This simple method allows the knife to retain its full thickness.
I believe the Tormek is most effective as part of a team. It relieves my hands of the strain of bench stones during everyday operations. In itself, that is a good reason for me to own a Tormek. If I choose to "sub contract" parts of the operation to other tools, that does not negate the value of the main tool.
I believe this topic has produced some valuable information for knife sharpeners. Scalloped break knives are a fact of life for sharpeners. We have suggested three practical solutions: Two low tech and low cost possibilities, adhesive micro abrasive paper. This is the lowest cost option. I believe that the second solution, diamond paste, is a better choice for those of us with low sharpening volumes. Rob's diamond file is certainly the superior choice for anyone with much filing to do. In fact, if I were starting from scratch, I would purchase a diamond file like Rob's at the start. The cost is higher, but the whole process is fully operational.
I believe this topic also illustrates the value of the forum process. Several ideas developing into stronger, more useful ideas. Thanks, Herman, for starting a good topic. I hope we will continue exploring it; there is much fertile ground to be found.
Ken
Having a Buck and a DMT tapered diamond hones, I can say they work well. One problem with the taper design is that it is easy to push the hone too far "through", consequently wearing the points off excessively. Careful consideration of this fact needs to be observed. The suggestion of a mark on the hone to show the limit of hone travel mentioned by someone in another post, would be an excellent idea.
Elden, this tool, which I talked about earlier in this thread, seems to solve this problem with the taper:
http://www.amazon.com/Columbia-River-Knife-Tool-VEFF1/dp/B0030IX772/ref=sr_1_6?ie=UTF8&qid=1429118663&sr=8-6&keywords=diamond+tapered+sharpening+rod
Ken, after reading your post I think I will invest in this tool. It will make a good addition to my sharpening station. With my Prime membership I get it for less than $31 US, with free shipping.
Here is the manufacturer's full product description:
This system includes an anodized knurled aluminum handle and two threaded 600-grit diamond-coated sharpening rods. The smaller rod has three 2-Inch straight sections in sizes 3/32-Inch, 3/16-Inch, and 1/4-Inch. The larger rod has three straight sections in sizes 11/32-Inch, 1/2-Inch and 5/8-Inch. The larger rod also has a 6-Inch flat side. The handle and rods fit neatly in a nylon storage pouch. The Veff Sharp is effective on most serrations and does not create egg-shaped serrations as tapered sharpeners do. It works equally well on gut hook knives and seat belt cutters. It is a versatile and indispensable tool that belongs in every workshop, tool box, tackle box and hunter's pack. It allows the user to keep a keen edge on all types of cutting tools including serrated and plain edge knives, wood chisels, wood carving and lathe tools, router bits, punches, scissors and saw chain. Proper use and care will ensure a lifetime of effective use. Light to moderate pressure is all that is needed for the diamonds to do their job. On most tools to be sharpened, simply blacken the cutting edge with a black ink marking pen. Then, following the original angle of the cutting edge, make a couple of strokes with the appropriate size of the rod across the edge. If you have the correct angle, the ink will be removed evenly. Once you have sharpened the first side of the edge correctly, you will have a burr on the back or flat side of the blade edge. Remove this burr by using the flat side of the sharpener and place it almost flat on the burr side of the edge. Use light pressure and draw the sharpener across the burr until it is removed. This will leave you with a keen cutting edge.
Sounds like a good tool, Herman. This and Ken' s approach sound like good ideas.
Quote from: Rob on April 22, 2015, 04:27:29 PM
Oh stop it....I love banana bread and I'm trying to lose weight!!!!
And you're slathering butter on your bread!?
Now you're just teasing :-)
Quote from: Herman Trivilino on April 22, 2015, 07:28:30 PM
Elden, this tool, which I talked about earlier in this thread, seems to solve this problem with the taper:
http://www.amazon.com/Columbia-River-Knife-Tool-VEFF1/dp/B0030IX772/ref=sr_1_6?ie=UTF8&qid=1429118663&sr=8-6&keywords=diamond+tapered+sharpening+rod
I ordered this tool and it arrived yesterday. I immediately used it to sharpen one of the knives in our set of cheap steak knives. It did an excellent job on the gullets of the serrations. I used the Tormek on the other side because it has a bevel. Then I finished off with the Tormek honing wheel, using the edge to reach into the gullets.
The only problem is that the diamonds on the new tool immediately wore off on the region where I was using it the most. I guess this tool is to be used only for touch ups. Not for grinding a new edge on a dull knife.
Last night, after sharpening that steak knife, I was thinking about what I could do to sharpen other serrated knives, like steak knives, bread knives, and lots of others. After reading about Ken's experience with the wooden dowel and diamond paste, I ordered some of the paste. I figured I could use it as my diamond honing tool loses its abrasive coating.
Then just as I was heading beddie-bye I got an idea. The inspiration comes from Ken's wooden dowel. Today I set up my router table and cut a piece of ¼ inch plywood in the shape of a circle of about the same diameter as the Tormek honing wheel. I rounded over the edges on both sides, removed the honing wheel, and mounted this in its place.
(http://i1291.photobucket.com/albums/b553/htrivilino/898b37fa-cd5c-43d2-94da-d047a75aebe5_zpsyxytqyf6.jpg) (http://s1291.photobucket.com/user/htrivilino/media/898b37fa-cd5c-43d2-94da-d047a75aebe5_zpsyxytqyf6.jpg.html)
I was now ready to try it out, but was thinking I'd have to wait for my order of the diamond paste to arrive. Then I remembered I had some valve grinding compound up in the attic. I bought it in the 1980's for an old Chevy truck valve job that never got done because the head was cracked. I've carried that stuff with me for three decades on several moves into two different states. Now was my chance to use it. I grabbed another one of those cheap steak knives and had at it. It worked beautifully!
I applied some of the compound to the wooden wheel with a paper towel. I also applied some to the knife. I ground away, then used the grindstone on the flat side, and finished up with the leather honing wheel and Tormek compound. Nice results.
I used to live in fear of knives with serrations. After having a pro fail at the job I got inspired to do something about it. I now look forward to someone asking me to sharpen their serrated knife.
Bravo, Herman!
I believe we are seeing this forum working the way things are supposed to work, with ideas improved by combined thinking.
As an aside, you posted the question about using diamond paste with the leather wheel. I wonder how a wheel fabricated out of MDF would work. MDF is available in sizes to at least one inch thick. The MDF might make a better bedding surface for the diamonds than leather.
Good use for your vintage grinding compound. The 1940s Popular Mechanics Home Workshop Club would be proud!
Ken
Quote from: Ken S on April 27, 2015, 02:02:10 AM
I wonder how a wheel fabricated out of MDF would work. MDF is available in sizes to at least one inch thick. The MDF might make a better bedding surface for the diamonds than leather.
Ahh... Good idea. I've got some ¾ inch MDF that I can use. The threaded mounting shaft protrudes only about 5/16 inch. I'm barely able to attach my 1/4 inch wide piece of plywood (1/4 inch is the nominal thickness, the actual thickness is a bit less).
A large counter bore will be needed to accommodate the large mounting nut, leaving the MDF very thin and therefore easily breakable. I think the solution will be to laminate a piece of 1/4 inch plywood to a 3/4 inch MDF donut.
I'll have to see what I can come up with.
Herman, don't forget that you can mount your plywood/MDF wheel on the grinding wheel side. For the mounting hole, drill a smaller hole (1/8" or so and sneak up from 15/32 to 31/64" and you will be quite close. I used a 31/64" bit to ream out some 5/8" OD Schedule 80 plastic water pipe to fit a wheel with a 5/8" plastic collar to the Tormek's 12mm shaft.
Lowe's sells 12mm fender washers which work well as spacers to fill a gap between your home made wheel and the 50mm side.
If you use the grinding wheel side, be sure you have the wheel turning away from the tool rather than in to it.
I see Lowe's (and probably other places) sell MDF in 2' x 4' size. The small size will probably be a lifetime supply for tormek research, and is much easier to haul!
Ken
Quote from: Ken S on April 27, 2015, 02:55:53 AM
For the mounting hole, drill a smaller hole (1/8" or so and sneak up from 15/32 to 31/64" and you will be quite close.
15/32" is equivalent to 11.9 mm.
31/64" is equivalent to 12.3 mm.
The shaft diameter is 12 mm.
Anyway, I don't have drill bits that are those sizes. I drilled the hole in my sheet of plywood with a 1/2" bit, which is 12.7 mm.
Having cut the circular piece with a router table I was surprised when, after mounting and using a few times, it was out of round. I improvised a truing tool using a wood chisel and my old straight edge jig.
QuoteLowe's sells 12mm fender washers which work well as spacers to fill a gap between your home made wheel and the 50mm side.
I may have to attach one of those to this wheel to keep it true when removing and replacing it.
Unfortunately I see no way of rigging up something that would allow me to leave both this wooden wheel and the leather honing wheel attached at the same time. Each would be in the other's way. One couldn't get away with using the Profiled Leather Honing Wheel or anything like it because the diameter is less than the diameter of the leather honing wheel and it would be in the way.
Attaching it to the grinding wheel side is an interesting option. Maybe I could rig up a bath of grinding compound to keep the wheel covered continuously. Then I could go into production sharpening serrated knives!
I used a piece of 3 x 5 card stock when I tried using a dry wheel on the T4. It seemed to work acceptably adapting the twelve mm shaft with the half inch wheel. I do not believe things are as critical at low speed.
The plastic knob should make quick changes practical. It makes switching leather honing wheels quite quick, one for valve grinding compound, the other for the honing compound.
Clever"truing tool".
Ken
Brilliant idea Herman. By the way, that is a nice looking dirty machine that looks like it is being used! ;) I think the price for your wooden wheel is cheap enough you can afford it even if it does get out of round easily and requires frequent truing, consequently wearing it away quickly. It may be that the wheel slid beneath the locking nut because of the oversize abor hole.
Herman, you said:
"The only problem is that the diamonds on the new tool immediately wore off on the region where I was using it the most. I guess this tool is to be used only for touch ups. Not for grinding a new edge on a dull knife."
Out of curiosity, did the diamonds come completely off or did the sharp points fracture off? The nature of diamonds is to fracture initially. The state they arrive in is excessively coarse. They "settle in" after some use. If the bonding agent is bad the diamonds could fall off entirely. There are two kinds of diamonds that are utilized in making sharpening stones. Mono-crystalline diamonds are said to last longer than poly-crystalline diamonds.
See the following concise article on stones:
http://www.sharpeningsupplies.com/Difference-in-Sharpening-Stone-Materials-W51.aspx
Also:
http://www.sharpeningsupplies.com/Why-Use-DMT-Diamond-Sharpeners-W15.aspx
I agree with Elden about diamonds fracturing initially. I purchased a DMT flattening plate, which allegedly flattens any sharpening stone in the shop. This is does, almost. I made the mistake of trying to finish flattening my grandfather's venerable carborundum stone. The diamond plate did flatten the stone, but the stone almost ko'd the plate. The plate still works fine for waterstones, however, I can hear and feel a noticeable difference in the cutting. I would not attempt another carborundum stone.
The plate is a great idea. and I recommend it, within limits.
Ken
Quote from: kb0rvo on May 04, 2015, 09:39:20 PM
Out of curiosity, did the diamonds come completely off or did the sharp points fracture off? The nature of diamonds is to fracture initially.
Hopefully they just fractured. All I noticed is the surface was much smoother and it didn't seem to cut as well. I'll have to take a closer look at it.
I believe the diamond technology has great potential. I just wish the information was presented without some of the hype. I don't fault the manufacturer for this, although they could be more specific about situations which can shorten the life of the plates. In my case, my plate will probably be flattening water stones long after I am gone, however, not as efficiently as when new. I expected some wear and I knew that the carborundum stone was difficult to flatten. i had spent about a dozen hours working on flattening it, and it was close. Had I realized what it would do to the diamond plate, I would have discontinued operations. It has sentimental value to me, but I doubt I will ever use it again.
I am curious to see what all the diamond paste can do. It did a very nice job on my bread knife with just a wooden dowel.
Ken
Herman,
I needed a lighting part today, and went to my local old time True Value Hardware store. While there, I looked at their files. I found an eight inch Niclolson round file with single smooth cut. Later at home, I found it was noticeably smoother than the typical bastard cut files. I believe its primarily for chain saws. It seems a nice middle choice between a bastard cut file and a diamond file.
Ken
Yes, those are available at lots of hardware stores for chain saw sharpening. I picked one up recently at a local discount hardware store. Nicholson brand. The diameter is too small for bread knives, but it would work on other serrated knives such as steak knives.
I neglected to post the diameter of my eight inch single smooth cut round file. It is 7/32", which should be large enough for bread knives. I also found the same file in a 1/4" diameter, which might work even better. These may be more difficult to locate than the smaller chain saw files, although it is packaged as a chain saw file.
Ken
If you happen to have a sisal buffing wheel with white or black emery compound, the below method shown on youtube works wonders.
The only thing I do differently to the video, is that I sisal-buffer only the serrated side, and then hone the flat side.
After sisal buffing the serrated side, on the flat side you can feel, and sometimes see an irregular microburr that you gently hone away.
Takes 2 minutes per knife all together.
https://www.youtube.com/watch?v=iaa0_ASuYGE (https://www.youtube.com/watch?v=iaa0_ASuYGE)