HELP! Smooth grinds, no belt marks

[trentu]

Can't get the flat grinds on this bowie to not have marks from the edge of the belt!! Wavy lookin' like some darn pakistan looking blade. How do I get it even from handle to tip? Thanks guys.

 

[Matthew Gregory]

Only grind in one direction, and move smoothly, meaning from left to right (or right to left), then remove the blade from contact with the belt and start again.

I grind from the plunge line to the tip, and edge up. It's all about smooth, even, consistent movements with even pressure until the tip. Then you should reduce pressure a bit to keep from thinning out the tip too much.

PRACTICE!!!!! And if you can watch someone that knows what they're doing, it'll take months off your learning curve!

 

[Alan Molstad]

And if you can watch someone that knows what they're doing, it'll take months off your learning curve!

Very true, and good advice!
I never knew what i was doing wrong until I got a video of a knife maker at work...

That showed me how to move with the steel at the grinder to have the flow to the blade I wanted.

 

[David Wesner]

Hi trentu, one thing that might help on this particular blade would be to draw file for your "finish grind", then finish like normal with emery or whatever system you're using. Use a jorgenson style clamp in a bench vise to hold your blade in a horizontal position. By clamping onto the handle of your blade, it makes for a pretty good way to draw file, holding it nice and solid. This is if you don't have one of those fancy knife vises that can be placed in many different positions. Practice for the next ones, using the before mentioned process until you are competent enough on your grinder. What type of grinder are you using ? Is your platen nice & flat ?

 

[trentu]

David, I am using a Grizzley 2"x72". I have real good luck on many of my other knives but this big one is giving me fits. I think the platen is okay. Will try the file finish and see what happens. Thanks guys.

 

[Barkes Knife Shop]

I grind from the plumge line as well. The same as MrPurple stated. To get the marks out of the blade, you will need to hand rub the blade to get it right. This is the way you remove the wavy from the steel. Note: When I hand rub my blades start out with 120 then 180, 240,320,400,600,800,1000,1500, and 2000 if needed.

Barkes :thumbup:
http://my.hsonline.net/wizard/knifeshop.htm
1.812.526.6390

 

[DCB4GOD]

I also have a Griz and the biggest secret found is after you harden it and go back to the grinder Glue a pliable piece of leather to the platen and it will smooth your grinds like you never thought it would

 

[jdm61]

i use a simpler "field expedient" version of DonFogg's handsandingbar for the heavy lifting. i take a 12 x 3/4 x 1/4 bar of brass and wrap paper around it and go to town.

 

[RJ Martin]

Get a 6 x 48 grinder, if you can.

 

[Rob!]

The 2" dig is always a problem for me but when I realized why it was there, it got easier to manage. It occurs 2 inches from your plunge and it happens because as you either start at the plunge or get to the plunge, the blade gets lifted away from the belt as the belt edge climbs the 'hill' of your plunge. This leaves only two points of contact between the blade and belt - and one of those is the edge of the belt which is now exactly 2" from the plunge - diggin' a trench.

It can be managed - even eliminated but whether you start at plunge or back into it, the risk is there. You proabably already knew this because your other blades turn out fine, but I thought I'd post it for others who may have followed this thread looking for an answer.

The other related problem I have encountered relates to the first touch of the blade to the belt and I know that it is impossible to apply it perfercly flat. Although it does go flat pretty quickly that first touch will be with one edge or the other and will leave a mark. To get around it, after my rough bevel has been established, I start my grinds in varying places around the middle of the blade length - then back up to the ricasso - then out to the tip. This means I'm passing over that first point of edge contact and it doesn't become a divot because it's in a different spot every time.

Hope that makes some sense.

Rob!

 

[flatgrinder]

I have a Grizzly too, for a large bowie, I use fresh 60 grit Norton Blaze belts, followed by 80 and 120 grits. Then I move to 180, 280, 380 grit wet/ dry paper wrapped around a micarta block and hand sand the blade.