Hi all,
I have been trying to learn how to sharpen for awhile now and for a week or so I was finally able to be a hair shaving edge on my knives. Well while looking more at what I was doing I found that I was sharpening my knives at too low of an angle, probably around 10 degrees. So, I try and raise my angle up to around 20 or so, and I can hardy form a burr, which i am thinking 2 things. 1, I am being inconsistent with keeping my angle and 2, I am using too fine of a stone since I am firstly trying to reprofile the edge. Mind you, the knife I am using to reprofile to around 20 degrees is not a knife I have tried to sharpen yet.
My set up is a 320, 1k and 5k Shapton pro stones and finish it off on a strop block.
I did have an extra coarse DMT stone but the the stone is going smooth.
Is a 320 grit able to reprofile a knife decently?
Also, my big question is, what is your set up from beginning to end when sharpening a new factory edged knife and how long does it take you roughly for each stone? Is there anything I should change to help me out?
Thank you for your help and any feedback you give!
The first and toughest thing for learning freehand IMHO is to reduce the amount of inconsistencies in your mechanics. I manage this by keeping my movements small and getting as much of my fingers and hands on whatever tool I'm sharpening.
On a new knife the type of steel might cause some issues, the blade might have a warp, uneven bevels, burned out steel along the edge, a grip/blade shape that doesn't play well with how you naturally hold or move the item across your abrasive.
These are some things to just keep in the back of your head if progress seems to be stalling - most likely you have too much angle play, the abrasive type is not a good match to the steel or you're starting at too fine a grit. 320 should be a good starting place on most jobs, but 120 is a virtual guarantee of speedy results and mandatory if changing the angle more than a couple of degrees. The lower grit values also have more tactile feedback so are a good learning tool in that respect. Too much wooble in your technique will virtually preclude good edges at finer finish values or make them very tedious in any event. The margin of error decreases with every jump up in finish, the amount of slop that produces an optically flat edge at 120 grit might produce a very convexed looking edge at the polishing stage. Learn the coarse stone.
The advice to master the low grit stones is good, as is the advice to stop at 600-800 if the edge is for utility work. This is the sweet spot for most steels between draw cutting efficiency and push cutting efficiency. As you go finer or more coarse from that point the edge will be more weighted toward draw or push cut, at the extreme ends of which is very inefficient at the opposing application. Some steels don't hold certain edge finishes as well as others, but most if not all will perform well in the middle range. Your maintenance methods to some extent will influence edge finish, some means are handier than others, especially on an individual basis. Intended use also should be taken into account when it comes to edge finish, but when starting out that's a secondary consideration. As you get better at managing different finishes, do cut testing at every step. I normally will not go higher than 1200 grit or 2k-4k waterstone, but for my hatchets, machetes, Chef's knives I want a brighter finish. For real utility hogs I want a lower finish.
As for speeding up the process, reducing the amount of play in your mechanics will yield the biggest reduction in time overall, once the coarse work is done, but even at the coarse level a lot of time can be wasted if there is too much play. The edge will become more convexed, and the apex will likewise become overly broad, removal of the burr can become a real hassle, it makes everything that little bit more challenging. Jumping to the next finer stone also will reveal curvature that then needs to be ground away or lived with.
I also try to always work from the shoulder out to the edge rather than just grind away on the bevel - there will always be some convexity to the edge (a little is a good thing), but it takes more time, effort, lost steel, and perhaps results in edges being more broad than intended if you have too much slop.
When sharpening a completely unknown knife I generally make a few passes with a medium or fine stone just to see what the current angle is. If not off too far or the edge is in OK shape I keep working at the medium to a finer stone. If the edge is way off I jump down to a 240 grit waterstone, 120 grit wet/dry, or an EC DMT stone. The progression will go pretty quickly through a 400-800 waterstone, 320 wet/dry, coarse DMT. Then on to 1k waterstone, 600-800 wet/dry, fine DMT. Normally I'll finish on a 2-4k waterstone, compound on paper over one of my Washboards, or a few passes on an EF or EEF DMT microbevel.
The entire process might only take 10 -15 minutes on most knives, maybe less - half of that will be on the coarse/first stone. If it takes longer, a lot of that will be observation/QC on some sort of mystery steel, dealing with a warped blade etc.
This is a short video I made showing some freehand control tricks, everyone has different mechanics etc but might be helpful to see how others go about it. When watching sharpening videos, look beyond the obvious and see how they hold and move the item more than what they might be saying, or the final outcome.
https://www.youtube.com/watch?v=SuGwd9YZ8_g
Martin
