Steve Sells Posted May 17, 2009 Share Posted May 17, 2009 [steve sells] tonight we have a request to cover Sharpening. Mark you asked, did you have something in mind or just general information? [markb] flat grind to 1/16' before heat treat then to sharpen you have grind again? [LDW] : I tell my kids every time I make a knife this one is sharper than anyone I have ever made [markb] or you have a chisel [steve sells] Yes mark leave a little metal to be sacrificial, because warpage is more likely to happen in thin areas, also the de-carb from the hardening [Finnr] I grind a bit to remove the decarb and establish the sharp edge [markb] So how would you do this without a grinder stones? [steve sells] I use the belt grinder [Finnr] Abrasive paper on a flat backing [markb] what grit [steve sells] files work,, actually hand files have one nice thing, its easy to KNOW when you remove the de-carb and get into good hard steel [Finnr] Yep! gets harder and you can feel it for sure [steve sells] 120 or 220 for after the HT then work finer till I get where I want [LDW] Hand sanding with a block of wood to the finest grit you wish to go to then hit on a buffer. Thats what I did for years [markb] ok sharpening on a grinder blade up? [steve sells] since I, and many others recommend more than one temper cycle, I temper first ASAP after hardening at 320 to 340 range, thermometer in oven is close enough for the first temper cycle this relieves stress from the thermal shock of the quench that may cause the steel to crack [Finnr] For now I finish my edges with a series of oilstones from soft to black super fine [steve sells] then I can clean up and the next temper is close to what I want for a targeted hardness, my thermometer or temper color [Rich Hale] Blade edge down for me [Finnr] me to. it's easy for me to catch the belt [markb] up? [Finnr] yep [markb] The first 320f temper will solve a problem for me [Rich Hale] If you stand to the side of me and watch me grind a blade on the belt grinder you can see teh wheel push in and deform that is dangerous if the cutting edge is facing into the grind [markb] do you slack belt on sharpening or contact wheel [steve sells] 10:15 pm: for my grinder I have 40 (replaced the 60 I used to use) and 120 Blaze, 220 and 400 Klingspor 321, and Norton x45 x 16, plus hand SC in 400, 500, 600, 1200, 1500, 2000, 2500, 3000. I do not use them all on any one blade, I use what the blade finish needs [Rich Hale] I dont right over the contact wheel I want total control on the angles [Finnr] Slack for a Moran type grind for me [steve sells] I slack for sharpening, but my slack is very tight, not loose at all. I actually run the belt looser when I use the contact wheel than when I do for slack belt grinding. [markb] I bought a grinder but not set up, start a whole new learning process [Rich Hale] It will be your best friend after you get to know it, wot kind is it? [markb] kmg vari speed, bought it in December [Finnr] : Just enough slack for a bit of give Steve? SWEET! [Rich Hale] GET some good belts and a pile of scrap steel [steve sells] : yup just a little give, on the finer belts I notice a BUMP when the splice comes over the flat platen [markb] i have lots of scap and I ordered belts, a variety [steve sells] also my Bader I slack grind with the combo platten , which is a 5 inch contact plus the short platen, so the slack area between is only about 4 inches [Finnr] LOL! I made lots of scrap learning what I have so far [markb] some ceramic and others 10" wheel and flat platen [steve sells] when I first got this (and I still do it) I ordered what I knew would do the order I had to get out the door, PLUS a 1 or 2 belts of a new type to test out. side by side, with what I knew worked well for me. [markb] I ordered 3 types in 50 120 400 [steve sells] Rich Hale here suggested the Blaze to me, and I have been buying those rather than the norton 960's and Klingspor ceramic ever since [Rich Hale] 4"x72"? [steve sells] I sill carry 120 grit in cheaper Norton 823 Zirconium for scale removal as scale ruins any new belt fast, so I use the cheaper cost belt for that only [Rich Hale] If you could test scale it is in the high rc60s [Rich Hale] I dont deal with scale [steve sells] that why I use throw away belts for scale removal @ 120 grit on one or 2 blades then throw it out, Old belt make heat, and that messes up the temper. [markb] how? [LDW] foil? Rich [Rich Hale] If I forge or weld a billet I remove scale with a carbide cutter in the mill or a hard grinding disc for heat treating I use Turco. it prevents scale in the forge, K and G sells it you dip let it dry for an hour and heat treat [markb] Good tip [steve sells] gas forge only ? or use with coal or charcoal? [Rich Hale] I have not tried it in coal [Finnr] I may give it a try over coal just to see [Rich Hale] It seems almost like a lacquer when dry, I am real careful when I put blades in and take them out [steve sells] me too they warp so easy when we squish them. I will turn this over to Rich Hale for a bit as I do ok, sharpening, but Rich knows a LOT more about the details of this topic than I do... so I bow to the more experienced man.. Rich if you please... [Rich Hale] Wot would you like to know about sharpening? [Finnr] You take your blades clear to the final edge on your grinder don't you Rich? [markb] Steps from tempered to final edge grits, or did we cover already [Rich Hale] Yes I do Finn I go up to about a 166 grit belt or so and then buff then to a finer belt and lightly touch the edge [markb] buff edge only or whole blade [Rich Hale] Ok Mark here is wot I do: I first polish the flats on the blade and then the hollow grind or now and then a flat grind. I always go to mirror polish, Then I do the edge ; I thin and sset the angles with a 120 grit belt. Then a 220. Then a 400 then a 1200 or finer then buff. I do not like to see any grinding marks anywhere on the blade. If I do I go back to whatever belt will remove them [markb] thats hard [Rich Hale] Then back to buff. then i use either a 15 micron or 9 micron belt for final edge. No that is persistence [markb] i have so many scratches with hand work grinder is scary, but i'm persistant [Rich Hale] There are really two kinds of edges. you can have a smooth edge that is really clean and nice even under a microscope. or one that has a little bit of a "tooth" to it. [markb] tooth would be what grit [Rich Hale] The grinder will take practice mark but it will get you farther in your work. 15 or 9 microns. It is not a "tooth that you can feel. let me explain that a bit [ApprenticeMan] I go 120, 220, 400 then fine scotch brite with green rouge to strop, and/or a buff on a soft wheel with green rouge [Rich Hale] You can get a small stick of white rouge from tandy that you apply to leather and use it to strop and edge after you can sharpened. I will polish the edge so it it realll smooth and sharp... like the barbers did with a leather strop for shaving with a straight razor. [Finnr] That's what I use on my strops [Rich Hale] That is a smooth clean edge. or yo can do like I do and use a fine belt after Buffing. Maybe a field exercise would help you decide wot you like [markb] ok Quote Link to comment Share on other sites More sharing options...
Steve Sells Posted May 17, 2009 Author Share Posted May 17, 2009 [Rich Hale] Take a knife that you know you like the way it cuts, (when the wife is out for the day) use a magnifier and looke close at the angles. [markb] always liked the way CASE knives sharpened [Finnr] Lacking a decent grinder I hand finish up to buffing. Takes too long but it will pay for the new grinder [steve sells] no one should be able to tell if its hand or machine if we do out jobs correctly, all they see is a nice finish [Rich Hale] Run a black marker on the side of the blade and blacken the edge ,,,,take a small stone or fine file and see wot angle it takes to remove the line right down the the cutting edge Does that make sense? [Finnr]Nothing gets on my sales table that isn't up to standard [markb] to determin angle [Rich Hale] Yes if you know that angle works see how to duplicate it. Then do the same thing with and ax or a hatchet [Finnr] Logical [Rich Hale] Look at the angle of the file or stone for both tests Then take a box cutter blade and do the same thing use and old one and sharpen it...keep a new one to look at. [markb] Lots to learn, but i have time latly [Rich Hale] Now sharpen everything you can find. The do some cutting tests...box cutter blades ar great sa they are cheap and you can compare noew to old to wot you have sharpened [Finnr] When I was cooking for a living a razor sharp edge was a must. No time to fool around . A dull knife is dangerous [Rich Hale] : I sharpen box cutters that I use i n the shop until they are wayy to small to use any more [markb] used to shave with straight razor and would try to sharpen- dull [Rich Hale] You still have a razor Make? give it a try after you do these things..I would strop it [Finnr] I do the same with X-acto blades [markb] Sold them all, lots of box cutters tho [Rich Hale] Folks talk about angles for this and for that..you will find that all sizes may need different angle surely a razor needs a keen edge and and axe is a wedge. Try a shop knife with a little "tooth Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.