Help - F1 honing problems

[Andy Purcell]

Hi,

I have used mouse mat backed wet and dry on my F1, inital results were ok , could get it to shave hairs,ect

I now seem to have lost the edge sharpness and stropping polished the edge but can shave and blade feels dull.

I am using 240, 600 and 400 W&D and finish on an old belt.

Where am I going wrong any ideas?

How many passed on each grade should I be aiming for, how hard to you press the blade into the mat?

I keep the blade fairly flat on the hone and apply pressure on the blade, I pull the spine back, dragging the blade edge accross the W&D,

An suggestions to get my F1 back in shape??

Thanks

Andy

 

[copper_head]

When your sharpening a knife you want to be pushing the knife edge (like you were cutting) rather than drawing it backwards, also you need to keep the blade bevel flush with the abrasive surface.

 

[The Joker]

Try this


http://www.bushcraftuk.com/community/showthread.php?t=15025&highlight=convex+blade+sharpening

 

[Andy]

When your sharpening a knife you want to be pushing the knife edge (like you were cutting) rather than drawing it backwards, also you need to keep the blade bevel flush with the abrasive surface.

Not wishing to sound rude but in this case your wrong. With most knives having a flat bevel to form the cutting edge you would use this method, however the F1 is a full convex grind and it's very common (normal) to sharpen in the method described in the first post

anyway back to the sharpening
the F1 has larger angle forming the cutting edge then a lot of other popular knives. If your using the soft side of a mouse matt with some knives you would have the whole blade on it (I do this when polishing the convoex kitchen knives). with the F1 you will need to raise the spine slightly, the more you raise the spine the less force you should use as you run the risk of the mous matt deforming too much and rounding off the edge of your knife.
I tend to use the soft side of the mousepad with the lower grits (up to about 800) and then use the harder side of the mouse matt with the higher grits (in my case upto 2000. Since evryone ends up putting a slightly different amount of force on the knife I can't give you an angle that will work for you. I think the spine tends to be about 5mm off the matt on the soft side and a bit more on the hard side when I'm polishing the edge

If you start with a high grit paper on the soft side of the matt and use it dry you can put some marker pen lines going from he spine to the edge and then see where your removing metal. I tend to aim for removing metal upto 1cm away from the edge (by using the higher grit paper your removing less metal when your getting it wrong experimenting with angles and force

 

[Hoodoo]

If you are using sandpaper on a mouse pad, you definitely want to draw the blade back, away from the edge.

What makes you think the edge is dull? A highly polished edge often feels dull. Sometimes folks mistake a burr edge for sharpness.

Did you mean to say that you can't shave now?

I would get a 10x hand lens and look the edge over carefully. If you did not remove the burr, you may have rolled it over. Knives with burrs quickly dull.

 

[copper_head]

Indeed, thought the F1 would be a flat bevel grind as the F1 is marketed as a bushcraft knife and that a flat bevel is the most usefull for general bushcraft, not familiar with F1 other than by reputation. Well you know what they say about presumption...

 

[Andy Purcell]

I have used the marker pen lines and found I was not taking metal from the edge, I have adjusted angle and pressure and now have a shaving sharp F1

One thing I have noticed that when I strop (old belt pulled tight from door handle) I can polished the edge, but can lose the shaving sharpness very easily if I strop too much?

Thanks for the help all

Andy

 

[Andy]

That tends to mean you've got a burr

rather then a leather strop I often use a 10,000 grit wet&dry paper, of course going from a 2000 to that means you wont get a edge polished like you would if you went trhough all the grits inbetween but it does cut off a weak burr rather then just pushing it back into line. If I need more then 2passes on the strop after then I've made a mistake.
I do think this is an effect of what happened when I went to uni I couldn't go out and use all these bushcraftknives I seem to have got, I don't spend as much time sharpening them when I can go out and use the things

 

[spamel]

There really does seem to be an art to this type of sharpening!! I am in no way an expert, I have had my only convex, a BRKT Fox River, for a few months now. I find that I only need to strop it now and then, try that before you sharpen next time, you may be surprised. When I do sharpen it, I tend to lift the blade so that I am removing metal from the side of the blade, but not quite the edge. After a few passes on the strop i can split the atom!!!!

Good luck with figuring it out, it is also a lightweight alternative to carrying big stones in the field!

 

[weaver]

I use a leather strop that I made by gluing an old belt to a section of 1x2 ( about 20 x 40 mm) pine wood 40 cm long. That is charged with white rouge compound. Not sure what the chemical makeup of that is. Some abrasive in a wax compound.

The strop being flat and stable it is easier for me to use. I can control the angle of the blade being stropped as well as the pressure applied. A few passes are plenty.

I can imagine that a highly convex blade would not work with this set up as well as a flat ground blade.

I think I would try gluing a thin rectangle of leather with the slick side showing on a thick mouse pad for stropping a convex blade. The bending moment would be shorter than a heavy strop suspended in air, so would follow the curve better.

A few blade smiths over here are using ultra fine diamond dust suspended in a gel or oil for stropping.