Sparks up or sparks down?

[Steve Sells]

I should move the 2 threads to reduce duplication,  but I always have edge UP when sharpening, and what is wrong with cutting edge into the belts feed ?  I never have any troubles.

[Marc1]

Interesting Thomas. Are they made in one piece of cloth with no joint, or perhaps a very good joint?

Steve ... I am no knife tragic, but sharpening experts I have seen, all sharpen with abrasive away from the edge. It makes sense to me. I imagine that the particles that meet the cutting edge will probably damage a very fine edge (?)

[ThomasPowers]

Steve I think it's more of an issue like how to reduce the curve in a blade after pounding in a bevel.  Many people never think of heating it and placing it bow up and tapping it down to the anvil as you are hitting the *edge*!

I too learned to grind blades belt running down,  edge up from a professional blade maker.

Marc1: good joints on good belts

[Marc1]

I always begrudged the bad joint on wood sanding belts that give when the temperature goes up on 40 or 60 grit. A diagonal overlapping just 1/2" glued and good luck to you. I suppose that making a good belt would mean to make the cloth belt strong first and add the abrasive layer over a properly joint belt, a much more expensive process. 

[bigfootnampa]

Well all of my belts are bi-directional.  Because I like to grind on the slack belt area, it's important to grind with the belt running away from the edge.  It is a rare but scary occurrence that I've experienced where the edge of a blade will catch the edge of the belt otherwise.  When this happens the blade swiftly slices the belt in half!  DANGEROUS!  I have found no advantage in grinding like Steve does it but it is very commonly done.  How you have your machine set up and how it is designed are factors.  I set mine to run nearly level on top and with the belt running away from my position.  Having worked quite a bit the other way in the past... I recommend this way.  I like to cut pretty long bevels (small angles) and instead of micro bevels I just allow the slack belt to impart a very slight convex curve to my bevels.  I find it a fast and dependable way to get the extremely sharp edges that I prefer.  This type of edge also works very well for carving hardwoods which is about my most critical type of work.  A slightly blunter angle works good for my axes.  Because I cut through both tough bones and very soft tissue with my fillet knives... I require quite extreme sharpness and steels that will hold it.