Disappointed in ZDP Calypso

L

leapinglizard

Joined
Nov 4, 2005
Messages
43
I just wanted to relay my disappointment with the edge holding of my ZDP Calypso Jr. I was initially very impressed with the fine edge that it came with and how sharp it was. Like a razor. It was and still can be sharpened to such a fine edge that it will literally cut arm hair in mid air. I have carried it for the past couple months as an EDC, but not really used it for any real cutting, other than the occasional cut on a cardboard box or to trim a cuticle. Well,....last week-end I had to redo a small section of home insulation/ Not much, just that which was covering a 10' section of air duct. I wound up having to make 2, 20" cuts through some foil backed insulation. No big deal. The first cut went ok, but I had to tear my way through the second cut! I was very, extremely disappointed! The edge on the Calypso had terribly dulled. It did not fold over, or chip, it just dulled. I suppose that it could have been due in part to the fine edge that I started with, but I had not vhanged the geometry of the edge from the factory shipping. I am no longer carrying the Calypso EDC and have gone back to my S-30V Native. It seems to be much tougher and more dependable. I had no idea that the Calypso was so fragile. And I was not even very tough on it. I truely expected that it would hold an edge much better. It is the only ZDP blade that I have. I have several S-30V's and have had much better experiance with them.
 
Did you try making the same cuts in the same material with your s30v Native? Did it keep slicing after making 2, 20" cuts? I don't have much experience cutting through insulation like that, but what is it made out of? I know card board can dull knives quickly, so can paper. Maybe the stuff you cut was far worse for the edge than cardboard or paper and dulled it really quick? I'm sure someone will come along with a better answer. :)
 
You carried it for two months without touching up the edge? Even with intermittent cutting, that seems too long. I sharpen my Manix at least every other week, or at least every time I feel it isn't cutting as well as normal.
 
2 by 20" foil backed insulation. I gues foil there is bit thicker then coocking foil and insulation itself - what it is? I know it may be some glass fiber...

It will be fair to try your CPM S30V on it if you have some of it left before such juggements and see how it will stand. If it is thick aluminium foil combined with glass fiber - I will expect any knife lose some sharpness pretty quick, especially small thin with such delicate edge as this one has. Thick convex edge will be more appropriate for this kind of job.

Thanks, Vassili.
 
Fiberglass and carpet will dull a good knife about as quick as anything I've come across. This is true especially with old material that has had a chance to get other things embedded in it. For that matter, anything labeled "glass" is bound to be hard on any edge. G10 (glass filled epoxy resin) will dull a good band saw blade faster than titanium. I've found that fiberglass tape and new fiberglass insulation are both pretty hard on anything with an edge from a Stanley blade to a good folder or fixed blade regardless of the steel if you repeatedly cut it without a maintainance tool handy to keep bringing the edge back to the kind of bite needed to make it cut cleanly. A little Lansky, or ceramic stick, or even a well used super fine diamond pad seems to do the trick and then once the job is done I can put that finer edge back that I once had on it. Dirty hemp rope that has been used for years will do much the same thing to a good knife.

Lots of times people cuss their blade without thinking about what they do with it. I heard a guy in the deer camp a few years ago talking loudly about how he never had any knife that cut worth a darn and that was why he used a cheapy Winchester (China made) Wal Mart knife for all his field dressing. At first I kind of chuckled to myself but then I got the opportunity a day later to watch him skin out his deer. As he cut it he rolled the bloody animal in the sandy dirt there by the river we camped at and of course the blood picked up the silica and rocks among other things so there was one factor to consider but that isn't all. He didn't bother to separate the hair, or even try to and for that matter he cut down into the hair rather than going in and coming up underneath and made no effort whatsoever to insure that he didn't cut a bunch of that dirty silica laced hair as he did the job. Of course he cussed that 'terrible knife' the whole while. The truth is I've got news for guys like that. It wouldn't matter if these guys had the best Bob Dozier hunter in their hands because the real problem wasn't the knife. It never was the knife. It was a little something many times often missed when it comes to using a knife, something we call technique.

STR
 
I saw many people were disappointed after they use their expensive knives from top brands to cut stake few times during the lunch on a china or glass plate - no steel can stand china or glass and dulls instantely when they touch it. You need diamond to cut glass.

Thanks, Vassili.
 
I still believe that the best all-round general-use blade steel is ATS-34/154CM. Tool steels have their niche, and their negatives. Others are soft, some brittle, some expensive, however it's been hard to improve upon that mentioned.

You can disagree, but can't deny my right to this personal opinion. ZDP may or may not be good, or great for that matter, but I'd be surprised if it turns out to be 'better' than ATS-34/154CM has been proven so far.

My 2¢.
 
You were cutting through fiberglass insulation? Glass is generally harder than any knife steel so I would imagine it would dull any knife, no matter how exotic, be it INFI or ZDP or whatever. Glass is up there on the Rockwell.
Every time you try to cut something harder than your blade, your blade will lose. That's the way of things.
 
My guess is that you were cutting through an FSK facing which is composed of Foil, nylon or fiberglass threads laminated to Kraft paper and then adhered to the insulation with asphalt. The insulation itself was most probably fiberglass. As pointed out glass is harder than steel. As the glass comes out of the hearth in a molten state, it goes through extremely holes in spinners (think of the world's largest Cotton Candy Machine). It could just as easily be poured into a block form and you wouldn't expect to cut that.

Most fiberglass installers use cheap thick steel blades (think "shank") which they'll generally hone on a grinder in the morning.
 
leapinglizard said:
The first cut went ok, but I had to tear my way through the second cut! I was very, extremely disappointed! The edge on the Calypso had terribly dulled. It did not fold over, or chip, it just dulled. I suppose that it could have been due in part to the fine edge that I started with, but I had not vhanged the geometry of the edge from the factory shipping.
Click to expand...

Most insulations tend to be very abrasive plus they are often cut on something hard as a cutting board which makes the cutting even more dulling on a knife. I spent several summers installing the pink fibreglass insulation, what you need to cut it well is an exceptionally acute and very thin edge which is left somewhat coarse. A highly polished edge will lose all slicing ability very quickly. I would be surprised if the S30V knife did any better, you might want to try it.

-Cliff
 
I had the same thing happen to an ATS-34 blade on a Buck folding alpha. It dulled really fast cutting foil backed insulation with the lawn as my backer. I just figured that I had inadverently gotten a wire edge when I sharpened it. Pretty funny.

Gordon
 
S30V will do no better on fiberglass insulation, I had the same experience with fiberglass patching cloth. :o I (now) use a Stanley box blade for anything like that.
 
When helping my dad insulate the house, I used the serrated knife on my SwissTool. It held up better than most anything else. It wasn't the steel, which is quite soft, but technique, and blade shape. The serrations made quick work of the paper backing, while the tip zipped through the fiberglass. Even when the tip was dull, it worked quite well. It was more of a crushing of the fiberglass, than cutting. Box cutters did okay, but there was a lot less blade to work with. YMMV

Like STR said. It's all about the technique. Of course, I have no experience with foil-backed insulation, but for the paper-backed stuff, I had the fiberglass side down, and the paper up. Every time I flipped the insulation, I had a much harder time cutting it. Paper up, I had no trouble. You also need to keep the insulation compressed, which helps a lot, othewise it's like trying to slice bread with a hard crust.

Daniel
 
Actually, for fiberglass insulation, in my oppinion large sissors work best, and even they dull quickly. Whether its in form of fibers or not, you are still cutting glass. I dulled a Lil'T in on swipe through fiberglass reinforced tape.
 
The best thing to cut fiberglass insulation with is shears (as HoB says above), and the best knife to cut it with is one that has been sharpened on the most coarse diamond stone, so it has micro serrations, it my hold up to about 4-5 cuts. The point is, don't cut insulation with knives. When I cut it, I use a box of very cheap razor blades, and plan on using them up fast!
 
The best way I have found to cut fiberglass insulation is with a 2X4:eek:
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- Lay the insulation down with the paperside up.
- Lay a 2X4 or other straightedge where you want to cut.
- Put a knee and left hand on the 2x4 to use your weight to flatten the insulation.
- Make your cut with the knife edge close to the 2x4 for a clean smooth cut.
 
This is almost like the thread where the guy *cut* into a magnesium fire starter and claimed his S30V "super-steel" was junk. :rolleyes:
 
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