What's wrong with my CTS-BD30P blade.

A

apsheron

Joined
Aug 31, 2011
Messages
17
Spyderco Manix2 sprint - a nice knife overall. The lock, ergonomics, jimping, FFG, etc., all nice and sweet and much desired by us all. But then I cut: 1) a tomato on a plastic board (gently!); 2) a bulk pack of AA batteries. After the first cut, the blade got multiple flat spots. Strange, I thought, and got rid of them by a few touch ups. After slicing through parts of a blister pack of batteries, however, the knife became just plain dull. Very dull indeed. I took it to a couple of sharpening rods and made it sharp again. Damage corrected, sure, but will it always need to be so frequently?

Hence, my question is this: is it (could it be) BD30P? As this is the only CTS-steeled knife I have (and it seems to be the only one out there in this steel), has anyone else tried Manix2 BD30P with similar outcomes? Could it also be that the edge geometry is such that it makes the edge too thin - perfect for light slicing (and effortless at that), but when something harder is met by it, the thin edge just gives up and dulls and folds? I just don't understand this as my S30V (almost the same steel) remains without a need to be sharpened much, much longer.

Anyone? Thanks.
 
In my experience that's common with Spyderco knives. Once it has been sharpened a couple times it won't happen again. However the factory sharpens them can cause the very edge to be a little weak.
 
Thank you ssblood. I guess that's common with some Spydercos since I've got a VG-10 Calypso Jr that I've used for years - no such issues. The edge shape on it is very different though.
 
Huh.

Maybe not relevant, I've had that with stainless Moras. You sometimes have to sharpen them a couple of times to get down to the "good" steel. I've heard it said that it's because of the heat of buffing them, but I'd guess that's speculation.
 
Did you run the blade against the metal AA batteries while cutting the package? Because that would do it - it's an easy mistake to make. I can't say I had a problem with my BD30P Manix getting dull for no reason... in fact it was quite the opposite - the factory edge held up extremely well until I unintentionally ran the blade along a bit of metal on the other side of the stuff I was cutting.
 
You could have a wire edge and it would do exactly as you describe. It's a thin piece of metal that can flop back and forth and moves around as soon as you hit something hard. Have you ever stropped a knife? That can help remove it a a cardboard cereal box (or similar cardboard) actually works pretty good and will pull the wire edge off. Put the cardboard on a hard surface with the printed side up and make an edge trailing motion at the same angle you sharpen at, or a few degrees less if you can. Worth a try.
 
I swear my CTS-20CP Para2 laughs at me whenever I cut cardboard, and I can usually go a few months without sharpening it. The only Carpenter steel to give me trouble is CTS-XHP, which likes to rust on me.
 
The only steel that has happened with was the CTS-XHP Manix2. It happened while cuttinf 1/8" zip ties at work. I sharpened the knife once, same beel as the factory and let me tell you that it held that edge for what seemed like 3+ months of medium use.
 
I'm also betting it's a wire edge, which seems very sharp for gentle cutting, but will fold easily under just slightly harder use. As suggested, sharpening the knife a time or two will likely remove most of the 'weak steel' (wire edge). A few light edge-leading passes on a fine diamond hone might very well scrub it off. If your 'sharpening rods' are ceramic, they're notorious for creating wire edges, if pressure is just a little too heavy. Try a diamond hone or, if you don't have that, some SiC wet/dry sandpaper should work too (light, edge-leading passes on a hard backing, like glass).
 
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Thanks for all the info! I'll give a cereal box a try.

Another interesting thing happened since: as I realized that the edge was very dull, I gently ran it on a diamond hone a few times only to realize, to my huge surprise, that the edge didn't come back. I tried a few more times to no avail. That never happened before, and even the stubborn D2 attained the needed sharpness quickly on that rod (DMT DS4F). So, I put the knife away to first do research and, hopefully, to tap on the wealth of wisdom and knowledge on this forum. Stopping by at a friend's house later, I stood in the kitchen, chatting, and spotted a sharpening rod's handle sticking out of a knives' wooden block - you know, a really cheap one, smooth, with longitudinal grooves. Almost subconsciously, I reached for the rod and touched my Manix on it a few times.

Guess what? The edge was back. Nowhere near, of course, its factory condition, it was, nonetheless, substantially sharper than immediately prior. Funny stuff...

May be what happened was the wire edge, being on the verge of disappearing after the diamond rod assault on it, only required a few more strokes on something like that sharpening rod, cheap or not, to strip off. I have yet to bring the blade back to the initial shaving-sharp condition, but much more happy I am.

Thanks again for all the help.
 
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I just got the same manix2 in BD30P right here on BF but only used it a few times. Love it so far and still going ok with the mediocre factory edge. Will keep an eye out for similar issues.
 
Could be that you got a bad HT, although I've never experienced this from Spyderco... then again, I don't own any of their blades from sprint runs. Another possibility is that whomever ground in the edge at the factory may have gotten it too hot and messed up the temper on the outer layers of steel along the edge.

If you have one, I would recommend sharpening it on a guided system like the EP or Wicked Edge and then see how long the edge stays. I suggest this for two reasons... (1) to grind away (slowly) the outer layers of metal along the edge which may have lost their temper and (2) to ensure the bevels are ground in evenly/wire edge is removed.

Keep us posted.
 
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