Sharpening flat ground jointer knives on Tormek?

[canuck]

Hey everyone. I bought an SVH-320 recently and used it to sharpen some 6" jointer knives that were pretty badly worn with some chips. I started on the Tormek, but it was taking a really long time to grind out the original flat ground bevel, so I setup the SVH-320 on my bench grinder and did most of the work there before going back to the Tormek to finish them up. I was happy enough with the final results, but it was a lot more work then I expected.

I found a good deal on an 8" jointer recently and the blades are in pretty good shape with no nicks, but they're a bit worn and could use a touch up. The manual for the SVH-320 says to "Grind the blade at exactly the original edge angle. Check the angle setting by turning the wheel by hand. The wheel should make marks on the whole bevel, from the tip to the heel". This seems to assume that the knives are already hollow ground, because obviously this isn't going to happen when the knives are flat ground. So I believe the advice is to start in the middle of the bevel and convert the flat grind to a hollow grind. That's what I did on the 6" knives, but it's a lot of work and doesn't really make sense to hollow grind the entire bevel if the knives just need a touch up. So what would be the best approach be for knives like this? Is it acceptable to just add a secondary micro bevel on the Tormek? I seem to remember reading that micro bevels were not recommended on jointer and planer knives. 

I've been reading lots of posts here about the SVH-320 and have found some good advice, but I haven't seen anything about how to deal with knives that are flat ground.

Cheers,

Andy