Thread: Difficult Blades To Hone - What is the solution?

Everyone has had blades that are difficult or seemingly impossible to hone. What experiences has everyone had, and how did you solve it?
After getting a problem blade sharp, did you have to go through gyrations each time you sharpened the blade, or did you find a permanent fix?

The worst blade was a Paki that had a warped blade. It is now a letter opener.

The second worst was a blade that had the heel ground way down. Probably to remove a large chip. This destroyed the angle of the blade. It simply would not sit flat on the hones. In order to make the angle consistent I would have had to grind off approx 1/4" of the blade. That was not an acceptable solution. It was put back on Ebay as a "collectible".

A correctable condition occurred when someone had placed their fingers on the blade during honing. There were two areas of the shoulder that were wider than elsewhere. This resulted in the blade being narrower at those points and thus would not sit on the hone properly. The solution was to hone on a coarse stone until the width of the blade was the same along the entire length of the blade.

Grinding the blade to remove pitting is another story......

Originally Posted by string

Everyone has had blades that are difficult or seemingly impossible to hone. What experiences has everyone had, and how did you solve it?
After getting a problem blade sharp, did you have to go through gyrations each time you sharpened the blade, or did you find a permanent fix?

I rejoined the forum as a rookie and got Lynn to keen it for me for free! :evil: P.S. don't tell him. ink:

Bob,

Glad you posted the question. I look forward to hearing from others. Whereas it is fairly simple to maintain a razor; restoring an edge on those the ebay specials some of us win is another matter entirely.

Sometime ago, I won a mint looking 6/8 Palmer Magnetic. The blade looked in excellent condition, so I thought it would be easy to hone up. Instead, the blade would fall shy of keen no matter what I tried. Finally, I put the blade under my 60-100X microscope and discovered the reason. Whereas the blade itself was pristine the bevel was corroded.

I sent off a message to Lynn and he suggested using a circular pattern, with my Norton, about 40 X on each side of the blade on the 4K side, keeping the blade very flat and moving slowly. After this he suggested a 5 X pattern strokes on the 4K and then 6 X pattern strokes on the 8K before checking it under the scope.

I use more of an oval pattern such that the blade is following the regular honing stroke when the blade edge is leading. When the blade is leading you're honing and with remainder of the circular (oval) motion you're in effect backhoning. This helps keep a wire edge from forming when sharpening aggressively. It seems to work well.

I don't regularly use a Norton, so I tried using my Achonite combo, the coarse side of which cuts very fast when used dry. I began by doing sequences of 20 X oval patterns, each side followed by a nail test. I kept up this sequence until I got a nail bite and, after checking the blade edge under my 60X microscope, was sure that all corrosion had been removed from the bevel. Once done, I returned to my regular honing method and sequencing.

Hal

Warped blades never take a proper bevel with a flat stone. Pitted blades often have swiss cheese syndrome and can never be used for anything but tomato slicers. Paki blades have such junk steel that no honing techniques I know of will result in a good shaving edge.

Otherwise, vintage razors have been very good to me. I've only one new razor - a Dovo - and that reminds me.... I've got to ask one of my fellow workers if he wants to keep it or give it back - haven't seen it in several months.

I've spent countless hours restoring Ebay specials and some of the things I've learned are:

• Don't deal with a chipped or nicked or unevenly honed blade by honing until it's fixed. Use a coarse diamond hone to file down the blade until the geometry has been restored, then use the same stone to restore the bevel or at least get close - then hone.
  
  Don't use a barber hone or anything resembling a finish hone on a blade that can't easily cut hair off your arm. Polishing a bevel to proper geometry could have been one of Hercules impossible tasks.
  
  Worry more about underhoning than overhoning. Overhoning has caused me some extra work a time or two, but underhoning has cost me hours and hours before changed my philosophy about only using the finest of hones on razors.
  
  restoring a bevel is more of a grinding process than a honing processs, in my opinion. Using a fairly coarse stone and fairly firm circular or back-and-forth strokes work just fine and you get where you want to go a lot quicker than babying it like you would a blade that's near finish.
  
  If you run your finger along the edge and feel anything jagged on the edge, continue with the coarser stone. If you feel only uniform microserrations, move up to a finer stone.
  
  Make sure you're restoring the bevel evenly on both sides. A blade can get sharp enough to let you overlook that but it won't be right until it's corrected.
  

also, I've completed my set of Spyderco Bench stones 8" x 2.5" from medium to ultra-fine. This set gets any razor ready for finish honing in no time flat. As far as I'm concerned, they're worth their weight in gold and cost a fraction of what a waterstone costs. The ultra-fine is not fine enough for true finish work, in my opinion, but it gets you close enough that the finish honing is easy. And they require no water or oil.

Great post Rob, thanks! I've been meaning to get a 1200 grit diamond stone from Howard for some time now for the very reasons you outlined above. Hal

Being that I don't yet have a 1200 grit stone, in order to start and edge on one of the butterknife ebay specials, I use the 1200 grit equivalent of wet and dry sandpaper. I cut 2" X 6" strip and glue it to a smooth peice of cardboard stock I use for mounting photographs. Seems to get the job done.

Hal

The hardest steel is about a 5.5 on the admittedly non-linear Mohs Hardness Scale. Anything harder than 5.5 like garnet, which is a 7 or diamond which is a 10 will abrade the steel and sharpen it. The Belgian stones have alot of garnet in them and have sharpened anything I've thrown at them. To quickly establish an edge geometry I use a DMT continuous diamond stone in Coarse, Fine, and Extra Fine. I also have a Norton Extra Coarse continuous diamond stone and that really hogs steel in a hurry.

Howard