Two Sharpening Questions

[Ravana]

Hello, I've noticed there is a dramatic difference between the sharpness of the curved portion of my Spyderco Persian versus the straight part closer to the handle. The curved portion is dull to the point where it doesn't cut paper at all; however, the straight part is as sharp as can be.

Not sure if this was something caused by inadequate sharpening at the factory or if the curved part of the knife naturally gets duller faster, though I am leaning toward the former.

Anywho, what is better, to wait for the straight portion to become dull then take it to the Sharpmaker all together or sharpen now and go over the sharp part again to make it even sharper. Don't want to do half and half since I don't feel comfortable being the judge of pinpointing where the sharp part begins and dull stops.

Also What do you folks sharpen your knives at? The Spyderco recommended 40 degrees for the first 5 or so times and then a 30 here and then or always 30?

Thanks,
Rav

[Nonprophet]

Barring some sort of defect (which is doubtful) in a portion of the blade grind, the thing I noticed in similar situations is that I tend to roll the knife in my hand when I get to acertain point, thus changing where the sharpening media hits the blade. Though mine is usually the opposite, the curved part is wicked sharp and the portion closest to the handle is less sharp. One way to find out if you are hitting the edge properly is it use a black permenent market and black out the edge of the knife. Then run it on the sharpener a few times and that will show you if you aren't actually hitting the edge or it will usually show you right away what the problem is. The angle of sharpening is a tricky and slippery slope (one Unit pushed me over long ago) there are so many variables like convexed edge, secondary and primary bevel, micro bevels on the actualy cutting surface, etc etc. The short and generic answer is the 40 degree (20 per side) standard edge is good for all purpose use an will stand more abuse without needing attention. The 30 degree edge is arguably able to be made sharper and will slice much better but the trade off is that you lose someof the durability of your edge. The debate has raged on since people first started making things sharp....

[Ravana]

Oh should have mentioned that I haven't sharpened it since I got it. That's why I put some weight to the point that it might have came out of the factory with an unequal sharpness.

[Nonprophet]

I wouldn't wait. If one portion isn't as sahrp as you like it, then clean the edge up. I could be that the curved part did get duller faster because that's what you use more or that got used one something that was ahrder on the edge. Put your own edge on it and it shouldn't be an issue. If the factory edge was inconsistent you would most likely be abel to tell by looking that it looked different. I've had some blades that when I get then look like the tip area and the rest were sharpened on two entirely different angles. Makes it a real pain to get a good consistant edge in them! Good rule of thumb is that if all else fails, get out the sharpener and fix it! Good luck.