Mon Aug 13, 2012 5:31 am
Welcome to the forum. Well for plane blades and chisels, flat stones are important. Using both sides and flipping the stone around can reduce the wear pattern a little but you will still loose flatness on both sides of the stone. Typically the middle and center of a stone wears most, depending on your individual sharpening style. So you do need to flatten your stones.
Nubatamas are certainly appropriate for chisels and plane blades. In particular you should choose among the harder stones. Specifically for the 1k grit, the Ume 1000 speckled stone comes in three hardnesses and the two harder stones are what you should choose for this task. There are videos for each of these hardnesses of stone on youtube. I would be tempted to go for the Extra hard (hardest) The finer grits should be suitable for this task as well and are sufficiently hard enough to give you precise edges. Consider the 4k, 5k and 6k bamboo - I'd pick the 4k. Then 8k bamboo.
Tue Aug 14, 2012 3:58 am
Yeah, for tool sharpening, you will need hard, slow wearing, fast cutting stones and keep them dead flat. My suggestion would be Shapton Pros with an Atoma diamond plate for flattening, as these were designed specifically for this task. However, the equipment is only 10% of the task, the rest is technique, so don't sweat it too hard.
This may be unconventional, but I think wood tools should be stropped when sharpened freehand as well, just be sure to use a stropping medium with VERY little give, like balsa or stiff leather.