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Final grind for blades chat june 19,09


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[steve sells]Welcome to Friday night knife chat last week we started to cover sand belt grits for getting a nice finish. since only a few of you were here, I hope you read the re post in the finish and polish section of the forum talked a little bit about grits and stones and how stones leave an open surface, a while belts tend to roll over the grain, a burnished effect... We have a BP for tonight about polishing, grinding and in general, getting a nice finish to the blades surface. Since Rich Hale wrote this BP, it makes sence to snag him and let him take it from here and do what he wants with it.... RICH:
[Rich Hale] Ok Let me speak a bit about this before I hot link it...sorry in advance about the lines. I do two kinds of finishes Damascus and mirror polished stainless...and for folders a hand rubbed finish on ss or carbon blades,,,Will not cover the hand rubbed this eve. The bp covers the mirror polish fairly well and tips on grinding. Let me say this first about damascus. I take my damascus blades to an A-16 finish before etch if they have pure nickel in them that lets the nickel shine bright after the etch. Other steel mixes I go to an A-45...The BP0235 explains those letters.

http://blackstoneforge.com/235/BP0235.shtml

[trying-it] Oh well what's a few lines among friends and great teachers..... going
[Rich Hale] One note as we look I not longer use the course 3M yellow belts and use norton blaze now
[markb] could you talk about the plunge cut Rich
[Rich Hale] Have you gotten through the bp Mark?
[steve sells] I will repost this chat as usual and try to make this BP available also
[markb] I just started grinding on the KMG
[steve sells] use scrap at first wont take long at all to get used to the new machine and contact wheels
[trying-it] I am playing safe this viewing; select, copy, and print all
[markb] Love vari speed, and have only used the platen. Noticed sharp belts make a BIG difference
[steve sells] You do know you can SAVE a BP. when you are on the page, use the SAVE PAGE feature in your web browser
[Finnr] Did that!!!!
[Rich Hale] And By the way this is one of the Bps that is not available until the wizards do the rest of the magic stuff that they do and surface all of them. But for now Glenn and Steve drug this one out for our use this eve.
[trying-it] print pages in notebook are saved even after puter crashes. BP235, so close, but was so far out of reach till now again. Thanks Rich & Steve
[fat pete] soo what if you dont have the grinder....how do u put your edge on
[steve sells] Files, even tho I do have a grinder
[lobodag] Rich do you free hand the start of the cutting edge or do you use carbide blocks glued with SG ?
[steve sells] I file the edge true by hand, my BAder is just a tool.
[Rich Hale] Ok most of us have had a look. Let me give a couple of keys to a nice finish...Belts...use poor belts,,either poorly made or used up , and you will get a poor finish. Pete we are working on finish here now and can talk aboiut edges with a belt grinder in a little while ok?
[Finnr] Can't hollow grind without one Flats and convex you can use a flapper and files
[fat pete] not a prob rich
[Finnr] Cheap belts aren't cheap in the long run
[Rich Hale] Ok when I cut out a blade blank and profile it on the grinder in prep for heat treat. I use a carbide scribe to mark two parrelel lines the lenght of the blade where the grind will follow The at the start fo the plunge cut I mark the blade with a sharpy I make those lines abouit .050 thou apart and try and grind until I can see the line barely that is roughly the thickness I leave to go to heat treat Did you all look really close at the Piece of wood that I shaped to supprt the spinf of the blae while grinding?
[Finnr] Yupper
[Rich Hale] It has about the right angle for how i hold the blade against the wheel and I hardly ever do a flat grind That wood is the key to a good grind
[Finnr] What size is that contact wheel Rich?
[Rich Hale]Now to begin the grind..you need a good light from above so you can see clearly wot yoiu are lcutting
[Rich Hale] 8", The wood is suppoerted by my hand and is resting solind on my belly,
[fat pete] Rich is your choice of grind hollow or flat ...is that a personal prefrence
[Rich Hale] When you take a new belt and grin on a sq coner to can see and feel the abrasives coming off.
[steve sells] I have a paid of lights one each side of the machine, on the ceiling in front of me as a back light, It is aimed toward me for killing shadows in the grinding side of the belt!
[markb] Do you hold above center line of wheel
[trying-it] yep, might need to find a willing belly here for help now
[Rich Hale] To save that belt use and old belt and do the first cut at a lbit of an angle and take the corner off the edge to almost the marked lines on both side
[Rich Hale] Then switch to a good belt Ilike a 40 or 50 grit blaze Grind til you are close to the line you just cut and look at the blade.See if the top line of grind is up high enoough on the blade
[brucegodlesky] all on one side??
[Rich Hale] If not grind some more but leave al ittle bit of gap in between the line and the belt I do one side at a time Bruce Except for taking the sq edge off
[brucegodlesky] don't you have problems with warping thern Rich?
[Rich Hale] Mark it is time to look close at the plunge cut area on the blade now and make sure it is the same as the rest of the blade.
[steve sells] ya got to keep them cool as you grind
[Rich Hale] Never had Bruce
[steve sells] 1 water quench when it gets warm in my hand
[Rich Hale] I dont worry a lot ab out cool unless i smell brunt flesh at this point they are going to heat treat
[brucegodlesky] OK just curious
[lobodag] I must have misted the knife center line
[Rich Hale] : Mark that make sense abvout the plunge?
[markb] I get a ragged uneven plunge
[Rich Hale] Two lines about .040 or .050 apart Tell me about ragged
[brucegodlesky] Ed Fowler grinds them into his thumbnails :-)
[markb] 10:37 pm: Rounded not straight in
[Rich Hale] Taht will support the bottom Bruce but this sports bottom and pushes the blade into the belt
[steve sells] grind what into thumb ?>
[markb] The stick may help to push in
[Rich Hale] Put a square on your weel and check to see if the rubber cushion is rounded off or square
[markb] I've been using platen
[Rich Hale] I round the corners on my wheels so the plunge cut is nice and curved.
[markb] how much rounding
[Rich Hale] I haev a thought for you Mark and will get to it soon
[markb] mine are new
[steve sells] I rounded the left edge of one the first time I used it, but I didnt plan on that :(
[Rich Hale] Not a lot I use a flat block of wood and some 120 paper...but on my grinder the contact wheel is drive wheel
[Rich Hale] Now to the plunge cut.
[m_brothers] lol, what kind of grinder do you have rich?
[Rich Hale] It is not easy to do with a course belt so I wait until after heat treat. I have a Hard core. I regrind the blades with a 100 grit like in bp or if I have left them thick a more course belt. Then when I never start at the plunge I start a half inch or so away and work into it. Roll the edge of your belt off the side alittle bit so it will curl up int the edge of plunge cut
[markb] Oh i like that with 220
[Rich Hale] Then I go all the way the legth of the blade...checking often to see top of grind line Yes it is more flexy....When you do other side of blade rool off the oter side a bit
[markb] OK
[Rich Hale] I have not tied this Mark but it may help when usiing the plated also
[markb] That platen is hard
[brucegodlesky] yes, it works on the platen also
[Rich Hale] The I run through the grits in the bp. And each belt change gets a close inspect for scratches
[Rich Hale] If youo cannot get a scratch out with a 220 it is likely from a 50...go back to 100 or 120 and do it agin,,,then with 220
[Rich Hale] WAtch really close that grind lines at plunger athe same on both side.
[steve sells] also be carfull not go get a wave near the pluinge
[Rich Hale] Wy it is so imprtant not to leave a scrtch and go up a couple of grits

Edited by mod07
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[markb] practice, practice
[steve sells] easy tpo over grind there
[Finnr] LOTS of good light is a must! Sucks to find scrtches when you are buffing. Don't ask How I know that!!:weird:
[Rich Hale] When I am done with a A16..I spend about three or four minutes on a buff with green matchless compound the a few minutes with pink no scratch,,,,done.......
[fat pete]because that scratch will still shpow
[Rich Hale] A shiny sceratch is still a scratch
[Finnr] 1And NOT what you want out of your shop
[markb]like a bad memory
[Rich Hale] Lets take a question break then we will get back to Jimmy and sticky pap0ers
[rthibeau] I didn't understand what a plunge cut is
[jimmy seale] well rh if i can finish better then i have to forge better and such.....
[Rich Hale] The start of the grind in front of the guard RT
[Finnr] Where the edge meets teh ricasso
[rthibeau] ok...thanks
[Rich Hale] This is method for ss I do the same for carbon but if 220 works best then that is a great plan let me tell you how easy this all really is--- I can do it
[jimmy seale] you use different set of belts for steel and ss correct?
[Rich Hale] I was not able to do any of this well for a long time had to learn to use the machines and the right stuff to use with it. No all the same Jimmy
[brucegodlesky] not really Jimmy
[Rich Hale] But let me make a guess. If you get ten feet of mild stell and cut it into ten inch pieces with a knfe prifile on each end byt the time you have ruined that bar of steel you will have learned a lot Ask JJ in as few days here he waws hollow grinding really well on a grizzy grinder I did not let him use the hard core as he has a grizzley Sticky papers
[lobodag] I start my grinds with strip of C2 carbide on each side at the start of the edge , glued on makes perfect edge stops and allows exact match to the grinde
[markb] I ground a piece of mild and liked it somuch i tried to heat treat it, forgot it was mild LOL
[Rich Hale] I am not sure the brand that I use..i call K and G and by some sticky backed 120 and 220 grit purple abrasive discs. They speak that language They are a few bucks apiece. After heat treat i use a flat grinding disc on a motoer and stick a disc on and grint the mill finish off the sides of the blaze,,120 then 220
[jimmy seale] i can gett 80,220 but wanted to get say 400/800 maybe a auto paint store?
[brucegodlesky] yep all the way to 2000
[Rich Hale] 1 The I use wet or dry sandpaper. I spray a disc adhesive on,,i get it from NAPA store ot a dure spray adhesive from ACEhardware.
[markb] do use vari speed Rich
[Rich Hale] And I start with a 400 then 800 then 1000 then 1500
[brucegodlesky] Rich you ever hollow grind on a disc?
[Rich Hale] MY disc is reversible but single speed No Bruce
[markb] what does rev. do for you
[Rich Hale] Buy good paper. I work the each side of the blade so the top of the disc is turning away from me..
[markb] OK what spd
[Rich Hale] After the wheel gets a bit gunky from spray I use acetone to clean it and start over Mark I see and use that alsmost every day and don't remember
[Finnr] 3M trim adhesive is good for sticking paper
[Rich Hale]I think 1750
[markb] kinda slow?
[Rich Hale] It was an old motor that lost the magic smoke I had them rebuild it and add a switch for the notther way
[markb] I've been liking slow on my belt but may change with experience
[Rich Hale] WE have some time for questions..I have covered alot...
[trying-it] Rich......... fastest way to obtain a nice usable belly? Lots of good cookies and ice cream, often?
[jimmy seale] do you know if them belts come in 4 x 36?
[Rich Hale] Mark my Hard core has a speed control I sun it almost alwasy in about the middle of the dial
[Finnr] Not much selection in that size Jimmy
[Rich Hale] Dont think they do Jimmy
[trying-it] Nope Jimmy, been there and done that
[Finnr] selection in one inch is just as bad
[trying-it] about 320 is best you will find for that size
[jimmy seale] well all i have seen is at lowe's and they ok but not so fine of grit
[Rich Hale] mark did wwe answer the plunge cut q?
[markb] My first grinder was FAST turned me off grinding, love the vari spd
[Rich Hale] They are the edge
[markb] Yes need practice thanks
[steve sells] 2 options buy a 2x2 machine, OPR glue and cut your own belts sorry
[Rich Hale] Which reminds me Ppete asked about the edge...After the knife is done handle is right blade guard everything is done and I have tried everything to fix anything needed. I sharpen the edge
[lobodag] most belt companies will make any size belt you need ,all good full line rewinders have several choices in brands
[Finnr] I eyeball my edges to about the thickness of a dime when I grind before HT. That too thick?
[Rich Hale] The edge is about .030 or soa s by now I have crowded the lines a bit.
[fat pete] how close id your edge till you finish
[Rich Hale] The with the blade edge facing the floor and about a 120 grit belt I gend the edge a little on each side..makeing sure to have the grind line up the side of the bvlade the slame on each side
[fat pete] so about a 32nd Watch the edge close and not burn it. When I develop both sides and get a wire edge...you will know it when you are there
[Finnr] Done that!
[Rich Hale] I switch to a 220 grint being carefull to remove 120 scratches. Slow speed here is better Then onto A45 And them A16 Then inspect in good light to see all scratches are gone
[rthibeau] does all that grinding, etc, work good on metals other than the ones you specified ??
[Rich Hale] Then to the buffer edge down and witha two hand solid grip...stay below center line of the buffer and lshine the edge up green first then pink on different wheel Mostly yes RT Now look at edge agin and lines go back to belt then buff
[rthibeau] ummmm.............rebar ???????...............................:evil:
[markb] Now that buffer is scary
[Rich Hale] If the edge will not shavev now look it closely and see if it has any flat spots on the very edge,,if so belts again
[Finnr] Most dangerous piece of equipment in the shopin my opinion
[lobodag]yup
[markb] Whats a cork belt do
[Rich Hale] If it shaves you are done if you want a sharper edge use a micron belt either a 9 or 15 9 is finer,,and just take a little on the edge.
[markb] do you use rouge
[brucegodlesky] things can get exciting real quick if you aren't careful
[Finnr] NEVER buff if you are tired or distracted. Accident waiting to happen
[Rich Hale]I haev a friend that swwears by them for handles Mark I have not tried one
[Rich Hale] My three buffers are the second most dangerous things in the shop
[Finnr] User the most?
[Rich Hale] I am the worst Thoughts I live by
[brucegodlesky] I was just hinking that Rich
[Rich Hale] Excellence is a decision.
[Finnr] Perfect is almost good enough
[Rich Hale] you do not have to have talent to make that decision persistence is also a decision. Good is the enemy of excellence
[markb] I struggle with that
[rthibeau] crawls into his hole.
[Rich Hale] Basically what i feel is that it is your choice,,what is the very worst thing that you will let out of your shp with yoour name on it........
[Finnr] If you aren't proud enough of it to sign it don't sell it
[Rich Hale] And if you do not sign it everyone will still know where it came from
[markb] you bet
[Rich Hale] I have once again run out of time and into the other spaces...any questions?
[Finnr] I have a box of "seconds" that ain't no one ever gonna get
[trying-it] I need a bigger belly
[Finnr]Don't look at ME Stan! LOL
[rthibeau] I'll feel better when I get to see Rich's personal collection
[Rich Hale] Me also Finnr and it drives my wife nusts..she usually pulls them out when i am getting ready to go to a show
[steve sells] last questions or comments before we colse up?
[Rich Hale] even the ones with ivory,,,,,gulp:cry:
[fat pete] Thanks rich ....really good job
[trying-it] thanks again Rich and Steve

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