Help! Knife just wont sharpen!

[Joethefish]

Hi all, having started to dabble in knife making and freshly sharpening all my tools with my spyderco sharpmaker a friend came along and asked if i'd sharpen his knife.
Now its a heavy piece of nasty tat but i agreed, But no matter what i tried i cant get it to take an edge. Its stainless steel and ive been trying with the sharpmaker for a couple of hours now. with no luck it wont even take enough to slice paper let alone be shaving sharp as the rest of my knives now are.. his loss obviously but after bragging about how sharp i was getting my tools, i dont want to admitt defeat! Any advice?
Joe

 

[addyb]

Do you know what sort of grind the knife is? Flat? Convex? Hollow? You might want to start with that and go from there.....

 

[Joethefish]

well to all intents and purposes it was a flat grind albeit a rather wavy one.. thats what he wants it returned too, its got a nice smooth bevel visible along its length in the light now but just isn't sharp, havnt got any way of magnifing it to see if there is a flat portion between the bevel on each side but the amount of passes its had through the sharpmaker i doubt it
Joe

 

[weaver]

The sharp maker is a finishing tool, if that. It seems that you are in need of restoring the grind. Try a belt sander or a large water cooled grindstone. Better yet send to someone who knows how to shape the edge.

 

[Joethefish]

I can redo the grind or usually would be able to but im staying at the girlfriends this week and dont have my belt sander, hoped to get it done sooner rather than later as my mate is going away. Guessing my only hope is some severe long hours with the sharpmaker
Joe

 

[Martyn]

The sharp maker is a finishing tool, if that. It seems that you are in need of restoring the grind. Try a belt sander or a large water cooled grindstone. Better yet send to someone who knows how to shape the edge.

Absolutely.

The sharpmaker is not intended to totally rework a completely knackered edge on a big knife. You need to raise a wire edge first with something a bit more agressive, you need to get the knife to sharp first, then finish up with the sharpmaker.

 

[Longstrider]

Sounds to me like it's either got a duff edge that needs a proper re-grind, OR it really is a piece of tat made of steel so poor (or poorly heat treated) that it really will not ever take a decent edge. I've come across a few blades like this in my time. No matter what you do to them, they simply don't want to "play ball".
I like to think that I can get just about any edge tool sharp enough to shave with, but some steel simply won't do it no matter how much you try.

 

[addyb]

Longstrider,

I think we all have come across blades that "just don't do it." In my experience, they're usually made in Asia and come with a low pricetag.

Joe, you might want to have a look at the stickied thread near the top of the forum entitled "Five Pound Sharpening Kit." It works wonders and I can only imagine how much of a finished edge the Sharpmaker will add to your blade.

Cheers,

Adam

 

[Chance]

After a couple of hours, you might need to clean the stones.
(sorry if this is ovosuction)

 

[British Red]

(sorry if this is ovosuction)

Ovosuction!

Nice one - I may have to adopt the phrase!

Red

 

[weaver]

I suspect that is derived from the proverbial saying DON'T TRY TO TEACH YOUR GRANDMA TO SUCK EGGS. I found the following excerpt via Google.

"To teach one's grandmother to suck eggs - To offer needless assistance; to waste one's efforts upon futile matters; especially, to offer advice to an expert. This particular expression is well over two hundred years old; it is just a variation of an older theme that was absurd enough to appeal to the popular fancy.

Nice spin on the saying.

 

[Joethefish]

Hi all... well as my post times suggest i was playing with this at some un godly hour of the morning... after closer examination i attacked it with a file and completely redid the bevel removing about 2mm from the edge to take out some bumps that although not that deep were causing the metal to fracture and flake behind them... After this went back over with some sandpaper then the sharpmaker.. its still shocking, well it almost has an edge, but however this folds and curls when you work it.. guessing from someones previous efforts at shapening using an angle grinder by the looks of it.. and yes it was dirt cheap and from asia.. i'll put it down to naff knife and walk away now.. told him to come see me or you guys when he gives up playing rambo and wants a proper knife!
Joe

 

[weaver]

Sounds like good advise.

 

[jamesraykenney]

I can redo the grind or usually would be able to but im staying at the girlfriends this week and dont have my belt sander, hoped to get it done sooner rather than later as my mate is going away. Guessing my only hope is some severe long hours with the sharpmaker
Joe

It is really easy to redo the edge with the sharpmaker... go to the hardware store and get you some 100,200,400,800, and 1000 grit wet/dry sandpaper(or what ever you call it over there...)

Starting with the 100 grit, wrap a piece around one of the rods and use one of those big black paper clamps to hold it in place... Then just use it like normal... It will keep the angle just like normal, but cut MUCH faster... You should be able to get it paper cutting sharp in less than 20 minutes...

Then go through the grits, until you are done with the 1000, and then use the coarse ceramic from the sharpmaker...

Simple, cheap, and it works GREAT!!!

 

[Zammo]

Or tell your mate to stop being cheap and buy a Frosts Mora for under £10.

 

[Longstrider]

... after closer examination i attacked it with a file and completely redid the bevel removing about 2mm from the edge...

If an ordinary file did the job then you definitely did the right thing giving up on trying to get a truly worthwhile edge on the knife. A properly heat treated blade of decent steel would be an absolute of a thing to try and attack with a file. The fact that your file "bit" into the steel of the blade should have told you all you needed to know about it.

 

[Joethefish]

My thoughts exactly... didn't post it earlier but i started by using the girlfriends nail file... and although slow i'll admit to doing most the work with that before i found a proper one under the stairs.... definately naff knife!
Joe