Question: Carbon Fiber Handle with voids?

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Sep 14, 2017
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Hi there,

As posted here https://www.bladeforums.com/threads/benchmade-mini-freek-565-1-whats-on-the-handle.1780321 I received my first carbon fiber knife today (with the rest 3 good knives), but find some voids on handle.

Contacted the dealer, so far they are very good at service and said I can just send it back to get refund.
But they also states, "Carbon Fiber is well known for having these small voids in the resin, especially around complex shapes."
And they said they've opened another unit in store, tiny better, but still have voids.

May I ask your opinion, if it's hard to avoid to have voids on carbon fiber handle?
May I have your help to let me know if the similar situation is happened on yours as well?

I like the knife, if that's common, I will keep it, otherwise, I will return it and get another one later this year when I go to the physical store for selecting.

Thank you.
 

soc_monki

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I have multiple carbon fiber handled knives. Some have voids, some don't. None are that noticeable, and don't impact the use of the knife. I wouldnt sweat it.
 
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I have multiple carbon fiber handled knives. Some have voids, some don't. None are that noticeable, and don't impact the use of the knife. I wouldnt sweat it.

Ya, you see it's my first CF knife. So, I ask your help to check yours - thank you for reply. (if you would like to help and don't mind, could you upload a picture of one of your knife with voids?)

I am also reading in the forums and search online, seems voids are existing in both low quality and high quality CF...
Am I too picky? :(
 

brownshoe

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Hi there,

As posted here https://www.bladeforums.com/threads/benchmade-mini-freek-565-1-whats-on-the-handle.1780321 I received my first carbon fiber knife today (with the rest 3 good knives), but find some voids on handle.

Contacted the dealer, so far they are very good at service and said I can just send it back to get refund.
But they also states, "Carbon Fiber is well known for having these small voids in the resin, especially around complex shapes."
And they said they've opened another unit in store, tiny better, but still have voids.

May I ask your opinion, if it's hard to avoid to have voids on carbon fiber handle?
May I have your help to let me know if the similar situation is happened on yours as well?

I like the knife, if that's common, I will keep it, otherwise, I will return it and get another one later this year when I go to the physical store for selecting.

Thank you.

I think it depends on the type of carbon fiber. For example, i got a custom folder with copper impregnated fiber covers and it chipped out around the lanyard hole, 2-3 mm piece. That carbon fiber had some small visible voids on the surface.

The maker asked if i use my knives hard and when i said yes he recommended the replacement covers be marbled carbon fiber since it was more durable. I took his suggestion. There are no visible voids in the marbled carbon fiber, nor in my Spyderco TMag, both of which have held up fine.
 
Joined
Sep 14, 2017
Messages
142
I think it depends on the type of carbon fiber. For example, i got a custom folder with copper impregnated fiber covers and it chipped out around the lanyard hole, 2-3 mm piece. That carbon fiber had some small visible voids on the surface.

The maker asked if i use my knives hard and when i said yes he recommended the replacement covers be marbled carbon fiber since it was more durable. I took his suggestion. There are no visible voids in the marbled carbon fiber, nor in my Spyderco TMag, both of which have held up fine.

I got a good maker positively follow up with the customer ;)
I've returned the knife to dealer and the refunding is on the way.

Learnt from this time, for a carbon fiber scales knife, I will prefer purchase in physical store.
 

CWL

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Sep 15, 2002
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10,157
Am I too picky? :(

Yes you probably are. You need to understand that carbon fiber is made in thin stiff sheets and is not a solid block of material. What you noticed as "voids" are areas where the CF cloth was folded into shape, and as CF is stiff, fitting into curved areas or odd shapes can cause it to elongate or even fail in that area. CF looks the best when layered at right angles or in gentle curves.
 
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Yes you probably are. You need to understand that carbon fiber is made in thin stiff sheets and is not a solid block of material. What you noticed as "voids" are areas where the CF cloth was folded into shape, and as CF is stiff, fitting into curved areas or odd shapes can cause it to elongate or even fail in that area. CF looks the best when layered at right angles or in gentle curves.

Before returning the knife, I checked a lot review videos on Youtube and photos in this forum, rarely see similar situation happened in any of them, plus some said it may not acceptable at a knife over $350CAD.
But good to know and thanks for clarification.
 

The Aflac Duck

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Yes you probably are. You need to understand that carbon fiber is made in thin stiff sheets and is not a solid block of material. What you noticed as "voids" are areas where the CF cloth was folded into shape, and as CF is stiff, fitting into curved areas or odd shapes can cause it to elongate or even fail in that area. CF looks the best when layered at right angles or in gentle curves.

Umm no... The carbon fiber on the knife in question was not “folded”. It’s milled from a solid block with all the weaves in parallel directions, no curves, folds, or otherwise. Voids are typically air bubbles in the resin used to hold together the fabric. In this case though, it looks like questionable machine finishing that is not unusual for Benchmade.
 
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Umm no... The carbon fiber on the knife in question was not “folded”. It’s milled from a solid block with all the weaves in parallel directions, no curves, folds, or otherwise. Voids are typically air bubbles in the resin used to hold together the fabric. In this case though, it looks like questionable machine finishing that is not unusual for Benchmade.

Same opinion here, coz I noticed the "defects" are appears on same area in each side of the handle. Looks like machine picked and gave press on it when proceeding.
 

The Aflac Duck

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Same opinion here, coz I noticed the "defects" are appears on same area in each side of the handle. Looks like machine picked and gave press on it when proceeding.

I have no idea what Benchmade’s process is, but carbon fiber is brittle enough to chip away if you’re drilling or milling it too fast or with too much force. Think of how concrete chips away in non-uniform chunks with a jackhammer, the idea is kind of similar.
 
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You can fill those small voids/holes in carbon fibre with liquid superglue and a sprinkle of baking powder (which will cure the superglue instantly), then sand to shape.
Recolor the spot with a black marker and Bob's your uncle.
Got this tip from an aerospace engineer who uses this trick to fill in small holes in carbon fibre propellors.
 
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You can fill those small voids/holes in carbon fibre with liquid superglue and a sprinkle of baking powder (which will cure the superglue instantly), then sand to shape.
Recolor the spot with a black marker and Bob's your uncle.
Got this tip from an aerospace engineer who uses this trick to fill in small holes in carbon fibre propellors.

Thanks, but that's not what I expected on a brand new product with over CAD$350 price. Will take note of this suggestion for a used one later.
 
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You can fill those small voids/holes in carbon fibre with liquid superglue and a sprinkle of baking powder (which will cure the superglue instantly), then sand to shape.
Recolor the spot with a black marker and Bob's your uncle.
Got this tip from an aerospace engineer who uses this trick to fill in small holes in carbon fibre propellors.

This is a horrible idea. Past voiding the warranty I doubt your gonna be able to finish it as intended or how it should look in any kind of way after you sand the finish away and have marker all over it.
 

Jsega51

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Op's knife is chipped, not a void.

Ok, send it back then. Most all CF scales I’ve had, had some sort of small defects in them. It doesn’t change my statement.
 
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Hmmm. The OP has two threads on this knife and each one he says there’s voids on both sides, and in the other thread the pictures show small pin hole voids on both sides. You’ve seen the pics, they look similar to voids I’ve seen in some cheaper CF scales.

In fact, what I would like to talk about is those in here. https://www.bladeforums.com/threads/benchmade-mini-freek-565-1-whats-on-the-handle.1780321
It's said that they are voids. As long as that post has less replies, I opened this post for discussing.
Frankly speak, as a new fan to blades, I am not sure what they shall be called, voids, defects, etc.. If the title mis-leading anything, sorry for that
 
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I have been using the combination liquid superglue & baking powder for quite a few years now, but i had my own doubts as well if it would work on carbon fiber.
Until someone came to me with a damaged Spyderco Positron that had it's wire clip twisted sideways, breaking off a small and thin piece of carbon fiber from the handle.
With said trick i was able to recreate the missing part almost invisibly.
Now the smooth carbon fiber surface of the Positron lent itself very well for this procedure, and i think the visual outcome would have been different had it been peel-ply carbon fiber.
 

Barry H

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Some custom knife makers are using a newer type of carbon fiber referred to as LVA (low void), there are several types of carbon out in the knife world. The marbled carbon is notorious for having voids.
 
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Yes you probably are. You need to understand that carbon fiber is made in thin stiff sheets and is not a solid block of material. What you noticed as "voids" are areas where the CF cloth was folded into shape, and as CF is stiff, fitting into curved areas or odd shapes can cause it to elongate or even fail in that area. CF looks the best when layered at right angles or in gentle curves.

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.
 
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