I bought the Harbor freight El cheapo 1x30 sander last night. I also picked up a machete and a "survival" knife for 5 bucks each to practice. I have been looking at all the posts on sharpening and on Horn Dogs post i see a wear marks right down the middle of the belt. So I am wondering how you hold the knife when using the belt sander. Originally I thought that you would hold the knife perpendicular to the belt and move from left to right or visa versa. From HD's Pics it appears from the wear marks that this may not be the case!

Any table scraps are appreciated!!! <img src="/ubbthreads/images/graemlins/grin.gif" alt="" /> <img src="/ubbthreads/images/graemlins/crossfingers.gif" alt="" />

My guess (yes, guess....i've never sharpened a knife using a belt sander) is that the wear pattern is indicative of a mechanical inconsistency of the sander, like an "over-tightened" belt, as opposed to how the knife is run across the belt while the system is operational. Kindof like how when you "over-inflate" a tire, the wear is in the center...."under-inflate" and the wear pattern moves to the outer edges. However, it could also be that the rollers that the belt rides on could force the belts to not be even also...i dunno, haven't seen one <img src="/ubbthreads/images/graemlins/laugh.gif" alt="" />

Yes, you hold the knife at your desired angle perpendicular to the belt.

The wear marks down the middle of the belt are do to the fact that you're grinding on a slack belt. When you put pressure on the belt the main part of the belt that is touching the workpiece is the center. It's also why you'll find sometimes that the area closest to the ricasso gets a little less sharp, because it's in contact with the abrasive less so on a knife with no choil, I spend a tiny bit of extra time grinding that. Let me know if you have any other questions.

Thanks!!! So what is the best way to figure out the angle you hold the knife at?
And one more thing....once you create the burr from one side of the blade, do you only knock it off when swapping sides or do you want to take it down more than that?

sorry for all the Q's but I didnt see these answered in any of the posts and I want to start off right, even with cheapo blades.... <img src="/ubbthreads/images/graemlins/grin.gif" alt="" />

http://www.youtube.com/watch?v=TLjFjT4vYsM this might help a bit-Luck <img src="/ubbthreads/images/graemlins/thumbup.gif" alt="" />

Make a burr on one side then flip the burr to the other as you progress up in grits. Mount the belt sander so you can use your body motion to pull it through rather than just your arms. Also move in a faster motion as the grits increase due to heat build up, start slow on cheaper blades till you get a "feel" otherwise it will be real easy to generate to much heat at the tip ... The angle is emtirly
up to you, a slack belt will make a nice convex that is easy to maintain

Thanks for all the help dawgs!!!! Much appreciated!! <img src="/ubbthreads/images/graemlins/bowdown.gif" alt="" /> <img src="/ubbthreads/images/graemlins/thumbup.gif" alt="" /> <img src="/ubbthreads/images/graemlins/grin.gif" alt="" />

This is great advice- Paul KNOWS what he is doing <img src="/ubbthreads/images/graemlins/thumbup.gif" alt="" />-I have personaly seen his work and it is " spot on" <img src="/ubbthreads/images/graemlins/thumbup.gif" alt="" /> <img src="/ubbthreads/images/graemlins/ooo.gif" alt="" />

That's why I like this place. Tons of great advice with a great attitude to boot. Thanks guys. <img src="/ubbthreads/images/graemlins/grin.gif" alt="" />

This is the place alright! <img src="/ubbthreads/images/graemlins/grin.gif" alt="" />

I also think Vic uses a "slack belt" technique to truly convex his blades.

If you're grinding not on a platen, you're convexing the edge. That's a "slack belt". Most everyone who sharpens on a belt grinder does so on a slack belt, which no matter how tight the belt is, is still convexing it. I removed the platen from my grinder entirely, but I will keep it on my kalamazoo and just grind above it.