Question: Carbon Fiber Handle with voids?

sharp_edge

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OP - no you are not picky. CF handles do not need to have voids, big or small, especially on not-so-cheap knives. Now of course everything is relatively. If we enlarged 50x, I am sure lots of voids will show up.

M54CzXe.jpg

IM9wL56.jpg
 
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That's not how carbon fiber scales are made. While the layup process (as with fiberglass) is used for things like car parts or high-end bicycles, where the weave and alignment of fibers is selected for particular properties like load-bearing strength, carbon can also be machined like any other solid material. Instead of doing a complex layup like a car fender, the raw carbon sheets are stacked in a rectangular mold to create large sheets of various thicknesses which are then cut into blocks. You'll find 1/4", 3/16", 1/2", and 1" thicknesses from most knife supply vendors.

The issue of voids, whether the part is an engineered layup or a sheet to be cut down into smaller blocks, comes during the curing process. Carbon fiber is cured under vacuum, which compresses the material by removing all of the air from within the epoxy/fiber matrix. If a bubble of air doesn't get removed, you have a void. Depending on what happens to the part after curing, you may never know there's a void; it's only when the void ends up on the external surface of the finished part that you really know it's there. As others have mentioned, shred or marble carbon fiber, where the fibers are chopped up into short strands and not woven in any particular pattern, are more prone to voids than the more uniform twill weave versions.

Carbon needs to be machined relatively slowly, and with sharp implements. If a machining tool is getting dull, it's more likely to cause chipping.

Glad to learn that, thanks for posting
 
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OP - no you are not picky. CF handles do not need to have voids, big or small, especially on not-so-cheap knives. Now of course everything is relatively. If we enlarged 50x, I am sure lots of voids will show up.

Thanks for reply and images posted, I think I saw the 2nd one somewhere too, ;)
I've returned the knife and waiting for the refunding amount back.
 

sharp_edge

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Thanks for reply and images posted, I think I saw the 2nd one somewhere too, ;)
I've returned the knife and waiting for the refunding amount back.

Yeah - the CF on that Spyderco is among the most beautifully done. Unfortunately I have sold it due to the half inch unsharpened blade edge though this is another topic of discussion.
 
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I've done a good amount of work with carbon fiber and study on composites in general, and I agree with @OrangeBlueOrangeBlue here. Voids are going to be caused by the production process, and for carbon fiber composites voids are going to be a bit more common than on other materials. If they didn't get all of the air out of the resin/weave before curing, those air pockets are going to appear as voids in the finished product. I'm not sure I've had any knives with CF handles where I couldn't find at least one imperfection when looking closely, but I would be unhappy if there were obvious defects.
 

fishface5

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I'm looking on a phone but those look like machining chatter marks and not voids caused by bubbles.

ETA: I have used super glue to fix issues with CF. Tape off the area you don't want covered in glue! Then carefully sand and buff.
 
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yamsi12

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About 5 years ago I bought a zt 0562cf. When I received it it had voids all along the chamfered edges real bad. Ended up sending it back and getting a replacement that was perfect. I have a pic of it somewhere I’ll post it if I can find it.
 
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Carbon fiber looks cool, I get that, but I don't understand why it is being used in an application like a knife handle (from a purely practical standpoint).
The strengths of the material are not being utilized in this kind of application, and as we see here, there are a number of weakness of the finished product.
 
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Carbon fiber looks cool, I get that, but I don't understand why it is being used in an application like a knife handle (from a purely practical standpoint).
The strengths of the material are not being utilized in this kind of application, and as we see here, there are a number of weakness of the finished product.

Interesting question IMO, I'm considering my next blade, still want a CF handle, but your post reminds me.
Let's see if there is more comments to this.
 

brownshoe

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Carbon fiber looks cool, I get that, but I don't understand why it is being used in an application like a knife handle (from a purely practical standpoint).
The strengths of the material are not being utilized in this kind of application, and as we see here, there are a number of weakness of the finished product.

I have two carbon fiber handled folding knives with no voids or problems. There are no "weaknesses" in the handles. I've seen and held many kinds of carbon fiber handled knives at shows. To me it's self evident why carbon fiber is used, it's strong, machinable and interesting..."don't buy no ugly knife." :)
 

The Aflac Duck

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Carbon fiber looks cool, I get that, but I don't understand why it is being used in an application like a knife handle (from a purely practical standpoint).
The strengths of the material are not being utilized in this kind of application, and as we see here, there are a number of weakness of the finished product.

It basically doesn’t scratch from carry. It’s stiff, strong, and light. It looks nice. It can be made true so everything lines up... The only weakness in this thread is Benchmade’s QC, otherwise this wouldn’t even be a thread if they machined it right the first time. A lot of misguided opinions floating around in here...
 
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Carbon fiber looks cool, I get that, but I don't understand why it is being used in an application like a knife handle (from a purely practical standpoint).
The strengths of the material are not being utilized in this kind of application, and as we see here, there are a number of weakness of the finished product.

as aflac said, its light and strong. G10 is as well (it's basically the same type of material, except made with fiberglass rather than carbon cloth). They can be polished, or they can have texture to add grip. They can be machined into interesting shapes, they are stable materials unlike wood. G10 can be colored, CF can have different materials woved into it or different colors of carbon cloth as well, or be made in a marbled pattern. And it looks amazing. That Spyderco up there is beautiful, as is my Magnitude.

So, what's there not to like about it as a handle material? It's even strong enough to be used without or with very minimal liners. I think it's a win.
 
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