Replies

1. 
   dave_in_london | Mar 26, 2004 11:58pm | #1

   Hi Frank,

   You'll need to be very careful using a grinder with a coarse wheel like that. Heat will build quickly and change the characteristics of the steel by removing its temper. The edge will then become dull very easily.

   If you must use a grinder, purchase a white aluminum oxide wheel as these run cooler.

   Better yet, you might do the course sharpening work on a piece of plate glass (perfectly flat surface) and then put a sheet of silicon carbide sandpaper on the glass. Remember that a wheel will cut a slight concave edge and this ultimately weakens an edge. Flatten the backside of chisels and plane angles, if they need it and then set the bevel angle that you want to use. This will probably be 25 degrees for most applications. A jig works best for this. Then move to the waterstones to finish them to a razor edge.

   
   

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   Edited 3/27/2004 6:55 am ET by Dave

1. 
   fgnoel | Mar 27, 2004 12:47am | #2

   Thanks for the advice.  Fortunately my grinder is variable speed and I can slow it down.  Do you think I can go from the grinder directly to a 400 or 800 waterstone?

   Frank

1. 
   Dave45 | Mar 27, 2004 01:36am | #3

   Another Dave here. - lol

   Unless you have a nick in the chisel, you would be better off starting with the 400 stone.  That 60 grit grinder will eat the edge of your chisel.

1. 
   TomB | Mar 27, 2004 02:28am | #4

   Dave

    I have found that using a grinder can be hazerdious to the health of your tools.Yes you can go from grinder to a 400 stone. But be prepared for a lot of hand work on your stone. I use a 220 diamond stone to do most of my rough work and than go to 1000 and up from there to a strop. A jig from Lee Valley is useful for beginners to get the hang of things, than you can do it by hand if you like. Have fun making sawdust.

2. 
   UncleDunc | Mar 27, 2004 07:12am | #7

   The white and pink wheels are aluminum oxide.

   Silicon carbide wheels are green or black.

   Silicon oxide is what they make computers with.

2. 
   eddiefromaustralia | Mar 27, 2004 06:23am | #5

   Frank,

   That's fine.

   I go from a coarse (36 grit stone) on a bench grinder to a 1200# stone. 

   I'm assuming that you're hollow grinding your chisels/irons here.  Be a different story if you were flat grinding the bevel and then trying to hone the whole primary bevel flat.

   Cheers,

   eddie

1. 
   JBD | Mar 27, 2004 06:55am | #6

   I totally agree Eddie.  Many people on this forum will understandably buy into marketing knowledge rather than react to actual experiential knowledge.  I bought waterstones back in the early eighties when most thought oil stones were the best, and I can assure you this - with some experience, you can do everything with a sixty grit grinding wheel or even a belt sander, and go straight to a 1200 waterstone and shave with the edge. 

   The comment about burning the steel with a 60 grit grinder, is waaaayyy off base.  the coarser the grit, the faster the material removal, less burning.  Burning the heat treatment out usually occurs when trying to remove steel with a wheel that is too fine, and/or clogged which needs dressing.

   A good 1200 grit waterstone (or diamond) will remove the coarse edge left by 60 grit quite easily.   So you spend an extra four strokes and three seconds longer to remove the extra metal that a 400 grit stone might take away faster?  So what?  A 1200 stone is all you need.

   I've built hundreds of thousands of dollars worth of national and internationally award winning art furniture as a professional, including my boat, with just a grinder and a 1200 stone for my planes and chisels.  Rockler and Woodcraft are waayyy overfunded by unneccesary purchases.   Sorry for the rant.  Y'all would be amazed at what you could do when you have more creativity than funds.  Heck, a cinder block, WD40, and fine sandpaper for my blockplane iron  has allowed me to shave crown moulding miters on site before.   

   "The furniture designer is an architect." - Maurice DuFrenes (French Art Deco furniture designer, contemporary of Ruhlmann)

   http://www.pbase.com/dr_dichro   http://www.johnblazydesigns.com

3. 
   RANGERP75R | Mar 27, 2004 05:30pm | #8

   Frank

      Agree with others that you can do it. I would avoid the grinder unless you intentionally want to hollow-grind. If so I would be very careful of the grinder. Regardless of what grit wheel you have, if you let the metal touch the wheel too long you will over-heat and lose the temper.

      Friction produces heat! Learn to to keep the blade or iron moving smoothly and quickly. Don't let it get hotter than is comfortable to touch. If you do go there, lay it on a piece of metal to dis-burse the heat quickly and let it cool before proceeding.

      If you do over-heat the metal it will turn a bluish color. Might as well grind it back and start over from my experience. An edge will collapse regardless of how sharp you think you got it.

   Regards...

   sarge..jt

   Proud member of the :  "I Rocked With ToolDoc Club" .... :>) 

1. 
   fgnoel | Mar 29, 2004 09:26pm | #9

   Thanks for all your suggestions.  They have been helpful. This woodworking is great fun.  I only wish I had started earlier.

   Frank

4. 
   fdampier5 | Mar 29, 2004 11:14pm | #10

   Frank,

      let me try to explain the sharpening theory.  the idea is to start out only as coarse as you need to in order to get everything straight..  then go to finer and finer grit wheels untill you get so fine that you can shave a frogs butt hair..

      If you start with a 60 grit wheel you may put deeper gouges into your tools than they already have..   It really depends on wht the cutting edge of your tools look like.. if they are jagged and rough looking like a picket fence in the poor side of town. It's possible that you'll need something that rough.. if however they are only dull thengoing that coarse will dramtically add to the time you spend sharpening them..

     You see first you'll put 60 grit scratches in, then the next grit will remove the 60 grit scratches and the following grit will remove the 150 grit scratches and so on and so on.. yo cannot go from 60 grit to 4000 without making all the steps in between..