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« on: March 23, 2013, 07:44:12 am »
Hi John,
The Tormek Japanese 4000 stone is a great stone, walking requires more finesse so running sometimes is easier and will teach you how to walk properly.
First, if the stone was badly wobbly it should have been returned, this is not acceptable in Tormek language.
Second 3-4 mm of truing is humongous for that stone what am I saying here, for any stone, When you true it you have to take less material in one pass than you use to take from the 220 one even if you have to take multiple passes. I would suggest you to start the truing from the left side of the stone in this way because the diamond tip is closer to the universal support posts when it gets to the opposite side, there will be less vibrations and less chipping on that side than if you would do it the other way around.
This is a polishing stone not a material removal stone, it is supposed to refine the edge form a 1000 setting of the original stone so don't expect any major steel removal as this stone was not designed for that. For polishing is far more efficient than the honing wheel in giving you a 4000 edge, and with no risk of rounding over the edge like it may happen with using the leather wheel if not done properly. The small ridges and valley left by the 1000 abrasive will be quickly levelled to give you a perfect straight edge. If the 1000 grading of the 220 stone is not done properly the honing wheel only will not polish properly the edge and will never be able to get you the straight levelled edge that would be required for a really long lasting extremely sharp edge it will give you more of a rounded spikes edge that has a polished appearance. The 4000 stone will always give you and precise straight polished at 4000 edge.
Now every abrasive will create a burr regardless the size of the abrasive used, the only thing that changes is the size of the burr which is proportional to the size of abrasive used, so if you had troubles with the burr was because of two possible reasons, either you were not really working the edge, or your fingers are extremely sensitive. After a proper 1000 grading and a proper angle set with the 4000 stone you should have not had to work more than 30 seconds on the edge and if you feel a burr after that the burr should be far smaller and weaker than the one left by the graded 1000. I personally have hard times feeling a burr after 4000 stone, but my fingers have a thick skin.
The manual states to not use the honing wheel after the 4000 stone but I would suggest you to use it only not in the same way as you would after the 1000 grading of the original stone. As I said the 4000 will create a small burr or will reduce the 1000 to a 4000 one, and I was able to see it with a cheap small microscope so a bit of honing wheel use will be effective in dealing with it. Tormek claims the honing compound is a mixture of 3, 2, 1 micron aluminum oxide based abrasive, but if you get a dab of it and rub it between your fingers you will feel the grit between your fingers which suggest that either the abrasives are present as lumps in that paste or they are not the claimed size. The good thing though is that immediately after starting using the paste these particles will break down so they will be the most efficient in dealing with a 1000 abraded steel and then by braking down in finer particles will do more of a finer polishing action. In my experience using the honing wheel after the 4000 stone freshly loaded with honing compound will defeat most benefits of the 4000 stone so I would suggest you to use a bit worn out compound after the 4000 stone. In my case I was able to put together a 1 - 0.3 micron honing compound that I use after the 4000 stone which is giving me fantastic edges for a "heavy" machine like Tormek Honing on the leather wheel is also very fast and does not require any extra pressure, you only have to remove a 4000 burr which is very small.
Now because you have a second stone to your machine your workflow has to be a bit different. First the wheels will never have the same diameter and if they will, it will happen for a short period of time. So I suggest you to find the offset of your wheels and use it in order to blindly set the angle on the 4000 stone, After finishing with 1000 put the 4000 wheel in place and using the marker method find the exact amount and the direction you had to move the adjusting wheel in order to match the bevel angle. Use that offset every time when you switch the wheels and you'll get perfect results. But be careful, the wearing rate of the stones will be different so once in a while depending on how much sharpening you do you will have to update this offset. Also because you probably have one machine I would suggest you to make a template that would allow you to project each tool the same amount from the SE76 which would result in the same bevel angle for the same adjusting wheel position.. For woodworking you could have 25-30-35 degrees projections or more on that template and you could group the tools based on the bevel angle, and first use the original stone for all the tools and then mount the 4000 stone to polish all of them, so you will not have to spend 30 seconds between tools to change the stones. To be sure though you would obtain the best results you would also want to change the water in the tray when you change to the 4000 stone, so you don't run the risk of mixing 220 grit with 4000 which only results in a waste of time and steel.
And I promise this will be my last suggestion, in one of the older threads I was talking about marking the wheels to avoid small manufacturing or wear imprecision that may results in non square edges or non matching ones. Mark the shaft, the stones and the washers, and always mount the stones aligning all these marks. When you do this first time you will have to true the stones taking the minimum necessary so when you change the stone the grinding surface of the new mounted stone will match the other one regarding the square-ness in relation to the universal support.
You will soon discover how much sharper your tools get.
All the best,
Ionut