Carbon Fiber Chemical Resistance

[sailfish]

Cleaning my most recent knife, a carbon fiber scale Sebenza, got me thinking about the chemical resistant properties of carbon fiber and probably more notably, the material used to bond it.

Just how tough is the stuff? How does it hold up to chemicals recommended by CRK for cleaning titanium such as lacquer thinner, Windex, or penetrating oils like WD40? What about common disinfectants like isopropyl rubbing alcohol? Has anyone ever had any kind of reaction? I'm hoping someone who really knows their stuff can chime in.

 

[Alberta Ed]

Good question. I suspect it's resistant to all that stuff, and if we were constructed the same way we'd probably last dang near forever.

 

[knarfeng]

Cleaning my most recent knife, a carbon fiber scale Sebenza, got me thinking about the chemical resistant properties of carbon fiber and probably more notably, the material used to bond it.

Just how tough is the stuff? How does it hold up to chemicals recommended by CRK for cleaning titanium such as lacquer thinner, Windex, or penetrating oils like WD40? What about common disinfectants like isopropyl rubbing alcohol? Has anyone ever had any kind of reaction? I'm hoping someone who really knows their stuff can chime in.

"carbon fiber" handles are CFRP "Carbon Fiber Reinforced Plastic". For knife handles, the plastic is generally epoxy. So all the properties are going to be similar to those of G10, which is "glass fiber reinforced epoxy". In both cases, the chemical resistance is dependent on the resin, not the reinforcing fiber.

There are literally thousands of epoxy formulations. The properties depend on the backbone, crosslink density, and the crosslinker. Some cure at Room temp, like the 5-minute epoxy you buy at Home Depot. Others require an elevated temperature cure. There is some variation in properties between epoxy formulations. So it's hard to state a specific set of properties. The properties of epoxies requiring elevated cure are typically superior to those only requiring a room temp cure.

However, I'd be shocked silly if any epoxy were degraded by exposure to room temperature WD-40, Windex, or rubbing alcohol. Most of them would be unaffected by wiping room temperature lacquer thinner other than possibly a slight loss in the glossiness of the finish.

 

[The Aflac Duck]

I’ve been using CF on knives for a while and had it come in contact with all of the things you mentioned sailfish and no problems at all. I often flush my knives with WD40 or Naptha if I’m being lazy, and still no problems

 

[sailfish]

I figured the carbon itself could handle just about anything. It's probably the epoxy or resin that concerned me the most seeing as how styrofoam will melt when exposed to certain chemicals. I've since done some reading on the effects of chemicals on fiber resin and there seems to be a consensus that it's virtually indestructible, and acetone is even a popular boat cleaner. Foam falls into a different category of plastic along with PVC and chemicals like those found in penetrating oils and solvents will actually break down the chemical structure of the plastic. Rigid crystalline plastics, which include nylon and polypropylene are unaffected. While I was unable to find an exact classification for epoxy resin (polyepoxide), given its traits and applications it seems it would fall into the latter category.

 

[lambertiana]

I figured the carbon itself could handle just about anything. It's probably the epoxy or resin that concerned me the most seeing as how styrofoam will melt when exposed to certain chemicals. I've since done some reading on the effects of chemicals on fiber resin and there seems to be a consensus that it's virtually indestructible, and acetone is even a popular boat cleaner. Foam falls into a different category of plastic along with PVC and chemicals like those found in penetrating oils and solvents will actually break down the chemical structure of the plastic. Rigid crystalline plastics, which include nylon and polypropylene are unaffected. While I was unable to find an exact classification for epoxy resin (polyepoxide), given its traits and applications it seems it would fall into the latter category.

Styrene is typically non-crosslinked polystyrene, and, like any non-crosslinked polymer, it is easily affected by solvents. Most epoxies are crosslinked (depending on the curative used), which makes them much more resistant to solvents.