Replies

1. 
   dtraversi | Apr 07, 2008 03:48am | #1

   wow- that's a new one on me- The manual says go ahead so I'd call the manufacturer and make sure they didn't recall that little bit of advice :-)

   Then I'd make a hefty block mount for the stone so I have plenty to hold on to- sneak up on it 1000th at a time -

   If it works/fails -I'd love a report back-

   dave

   Settle Down People... Settle Down
2. 
   danmart | Apr 07, 2008 05:27am | #2

   Do not do that!

   If you are feelin' a little lazy, unplug the little guy and rotate the blades around and sharpen the edges with a stone or diamond plate one blade at a time. This isn't the finest way but it does work and its safe. In simple terms its just "freshing up the edge a bit" to get some better cuts without taking the blades out.

   Years ago I read of a guy that thought putting the blade in a tablesaw backwards and running it at a setting just below the table surface and running a file or stone across it while it was spinning was a good way to sharpen his old blade. I was so amazed that the guy was serious about telling people to do this, I forgot to ask him if he had a variable tooth pattern for fear that he might think it was OK to explore this unsafe practice.

   Be safe. Take your time and do it with no power applied to the machine.

3. 
   philip | Apr 07, 2008 11:11am | #3

   I think you are misinterpreting whatever is being said in that manual. What you describe is the process of JOINTING the knives whilst they are in the block- all this will do is ensure that all the knives project an equal amount from the block, and be be in the same plane as the tables.
   Then you will be left with knives that a) blunt and b) have no clearance. It is a dubious process , a waste of time.
   The next step which should have been described is the use of a knife grinding attachment which references off the outfeed table and will then grind the knives in situ.
   I have seen this type of set up in factories and it was not good in most cases. Far better to touch up the knives by hand honing them in place until they require re-grinding. Then they must come out , be professionally ground and correctly reinstalled in the block and you should be able to do this several times before they become too narrow and you need to get new knives.
   If you compare the cost of a professional grind against a set of good quality knives you will answer your last question.

   Philip Marcou
1. 
   BrianDerr | Apr 08, 2008 06:37am | #6

   I guess I agree with philip here. Referencing the outfeed table seems like it would be the wrong angle for sharpenning (even touch up), as it would provide no clearance or relief angle to the bevel as it enters the wood. Jointing, sure, but . . . still sounds like a waste of steel. Brian

4. 
   oldusty | Apr 07, 2008 05:55pm | #4

   PM66,

               This was used for honing or just a quick freshen up , not for full on  sharpening.

                The manual did not suggest using this method for jointing the blades although it could certainly work , as Philip said ,it would be a major mistake and waste of time and knives .

              I have spun the cutterhead by hand to hone with a stone but just don't have the desire to turn it on while holding on to a stone , hmmm,  hmmm .

             dusty

5. 
   Disputantum | Apr 07, 2008 09:52pm | #5

   I've read about that technique before. I don't remember where but it was in a published how-to. I tried it and used it for awhile but not anymore. The problem was it left hollows in the stone. I used the fine side of a carborundum stone.

   Here's how I did it: I adjusted the outfeed table until the blade just hit the stone. I clamped a block of wood to the infeed table for the end of the stone to bear against. I placed the stone against the block over the cutterhead, turned the jointer on, and moved the stone back and forth. I stood alongside the outfeed table. If one dosen't use the block, the jointer will shoot the stone through the shop wall. Also, if the outfeed table is set too low, the knives will break the stone.

   It worked well, but now I use a hone made for jointer knives.

   ne sutor ultra crepidam:  Disputantum Semirotten Woodworking

6. 
   terryb | Apr 14, 2008 11:41pm | #7

   My General 8" came with instructions for doing that. I found it hard to believe. If you sharpen knives that way and you survive, there will be no relief behind the cutting edge and the wood will be burned, the knives will heat up and go dull very quickly. Build a jig and sharpen on a flat surface with psa silicone carbide paper. I could post a pic if it'd help.