Tutorial or help on using a file for flat grind?

Sean Jones

Well-Known Member
I have a 4 X36 grinder that I used for my first knife, but I found it extremely frustrating and time consuming. It just doesn't seem like the right tool. Plus when I was done I don't think I really had a flat grind.

So now for knife number two I've decided to use a file. I've made good progress and I think it looks much better than my first knife. However I'm in the final stages and want to make sure I don't mess it up.

So any tutorials available for this? I recall a thread about this but I haven't been able to find it. Or do I just need to be patient with my grinder? Or?

Any suggestions or help would be appreciated. I can post pics later if need be.

Thanks
 
It sounds like you're in the same spot I was a few months ago. Here's a link that has helped me a great deal. It's a slow process, but the end results can be quite amazing!

File Guide and Tutorial
 
Welcome to the club of those who have tried a 4X36" sander as a grinder and become frustrated. Google up draw filing which is basically pushing or pulling, depending on the way the teeth face, across the work sideways. It's surprising how fast this cuts. Get a single b@stard cut mill file for rough work and a single smooth cut mill file to refine the scratch pattern before going over to sandpaper. Also have a file card on hand and use it often. Frequently switch to an unused section of the file as you work to use clean teeth.

I have seen one modification of a 4X36" sander that could help. A gun maker installed a secondary platen on top of the on the sander came with to extablish a ledge right under the edge of the belt. You might be able to get a ceramic platen that is four inches wide and glue it to the existing one with a high temperature epoxy, something like JB Weld. Install a couple of very short sheet metal screws as a ledge for the bottom of the platen to rest against for support in case the adhesive ever softens. I would also take the platen on the sander down to bare metal before glueing to give the best bond.

Doug
 
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Welcome to the club of those who have tried a 4X36" sander as a grinder and become frustrated. Google up draw filing which is basically pushing or pulling, depending on the way the teeth face, across the work sideways. It's surprising how fast this cuts. Get a single @@@@@@@ cut mill file for rough work and a single smooth cut mill file to refine the scratch pattern before going over to sandpaper. Also have a file card on hand and use it often. Frequently switch to an unused section of the file as you work to use clean teeth.

I have seen one modification of a 4X36" sander that could help. A gun maker installed a secondary platen on top of the on the sander came with to extablish a ledge right under the edge of the belt. You might be able to get a ceramic platen that is four inches wide and glue it to the existing one with a high temperature epoxy, something like JB Weld. Install a couple of very short sheet metal screws as a ledge for the bottom of the platen to rest against for support in case the adhesive ever softens. I would also take the platen on the sander down to bare metal before glueing to give the best bond.

Doug

If you want a glass platen 4 inches wide, go to a glass shop and have them cut you a piece of tempered glass, 1/4" thick, that is the right width and length. Have them dull the edge slightly and radius the top where the belt first comes into contact. JB weld works great make sure the glass is perfectly aligned for where the belt runs.
Since you were on the subject I thought I would just add my little bit to your post.

Fred
 
Thanks for the tips and the link. I like the idea of the secondary platen and the tempered glass. I'll have to try that. The biggest problem I've had with this 4 x 36 is there really isn't anywhere that the belt is free from the underlying metal. Making it next to impossible to grind evenly all the way to the edge.

I've bought a 1 1/2 HP motor as my first step, along with a set of plans, in building a true knife grinder. But it's taking time. My new job however isn't quite the time hog my old one was, so hopefully I will have more time to devote to both a new grinder and more knife building.

Thanks again for the help
 
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