Thread: Blade warped or is it me?

I got a cheap blade off ebay and was trying to put an edge on it last night. It's a Genco B5, full ground, I think. I bought this blade to learn restoration and honing.

Anyway, I started out on a Norton 4000 and wasn't making much headway. The blade was as sharp as a butter knife when I started. I then switched to the 1000. During the process I noticed one side of the blade, the side I push away from me, the grind line was heaviest in the middle and lighter at the toe and heel. On the opposite side of the blade the grind line was light in the middle and heavier at the toe and heel. I tried to compensate by putting my finger over the spot that was light as I pulled toward me and at the toe and heel as I pushed away. Anyway, my attempt at compensation didn't work. I started out trying my best to keep the blade flat and use even pressure. I did manage to get the blade sharp enough to shave with it last night, but it certainly wasn't optimal.

Is it possible that the blade is bowed a bit? Or do you think it's my honeing that caused this? How do I correct this?
Thanks,
Kent

Sounds like you may have a slightly warped blade. Try putting a thin line of magic marker along the cutting edge and do 6- 10 laps on your Norton 4000 stone. It will take off the marker where it is in full contact with the stone. If there is marker left behind it is a pretty good indicator that you have a warped blade.

Another possibility is that your stones aren't lapped flat.

If the blade is warped it still can be sharpened up but it takes a different tecnique.

Originally Posted by CarrieM

Sounds like you may have a slightly warped blade. Try putting a thin line of magic marker along the cutting edge and do 6- 10 laps on your Norton 4000 stone. It will take off the marker where it is in full contact with the stone. If there is marker left behind it is a pretty good indicator that you have a warped blade.

I did use the marker trick while I was sharpening, I didn't count the laps, but I noticed there was some marker left in the spots I mentioned that would be high after a few strokes.

Another possibility is that your stones aren't lapped flat.

The 4000/8000 combo I just lapped the other day, and the 1000 was brand new. I suppose I should have lapped the 1000 to before using. I just spent hours correcting my first lap, which was a bad one, and I didn't have the stomach for it yesterday.

If the blade is warped it still can be sharpened up but it takes a different tecnique.

I'll try to take some pictures of the edge. I don't know if my camera will take a good enough picture though. What kind of technique would I use with a warped blade?
Thanks,
Kent

Usually with a warped blade, A rolling X pattern. using more of the side edge of the stone rather than the center of the stone seems to work well. I am probably not decribing it well and hopefully someone else can clarify what I am trying to say.

Originally Posted by CarrieM

Usually with a warped blade, A rolling X pattern. using more of the side edge of the stone rather than the center of the stone seems to work well. I am probably not decribing it well and hopefully someone else can clarify what I am trying to say.

There's a wiki on that stroke which says it's for a blade with a smile. Rolling X stroke - Straight Razor Place Wiki

My blade's edge is warped a different way. If you lay the spine down on a table and looked straight down on the edge from above, it's there you would see the smile. In my imagination is more of a bow shape. Not that you can actually see it with the naked eye, it's very slight if it's there at all.

Hopefully my description is good enough for people to understand.

Does the rolling X work in this case as well? It seems like it would work on one side but not the other.
Thanks,
Kent

Originally Posted by keenedge

Does the rolling X work in this case as well? It seems like it would work on one side but not the other

IME it will. OTOH, not having your particular razor in hand there may be exceptions. Put the marker on the concave side and note the stroke you have to use to make contact with the edge while keeping the section of spine that is opposite on the rock. Repeat that stroke. You may, as CarrieM said, have to work more toward the edge of the hone. I like to knock the sharp edge off my hones BTW. Either with a diamond plate or sandpaper.

The ideal edge will be consistent in width all along the blade. IME when you have these warped spine issues that isn't always possible and you have to go with what you can get so don't let that worry you.

What CarrieM is trying to say is that you need to have narrow contact with the hone so the entire edge makes contact. SOme people use narrow hones to achieve this. With wider hones you should tip the blade up a few degrees with the heel making contact with the hone. Slide the blade off the hone keeping the same angle. When the middle of the blade reaches the edge of the hone lay the blade flat to complete the stroke. Flip and repeat. This stroke is similar to the rolling x except that the rolling x only uses the flat surface of the hone. Here you will be using the area closest to the edge of the hone from the heel to the center of the blade and only laying the center to the toe flat on the hone or even raising the heel if there is a smile of any consequence.

Caution: You need to be sure the edges of your hone are beveled or have a radius on them. A square edged hone may cause damage to your blade.

Good luck.

Oh, a flat hone would be best. If it's not flat you are adding other variables that will effect the quality of edge and time required.