Why carbon fiber is covered thick clear lacquer coating?

[Robocop2310]

Hey guys, I've searched far and wide with no luck and have always wondered by carbon fiber products such as a carbon fiber Nismo 400R two-piece wing I recently purchased for my R33 GTR come covered by a thick layer of clear lacquer. 

I'm no CF expert so please excuse my lack of information here, but why don't products come out with pure dry CF and always covered by this thick coating? Is it because of the high price of CF, giving it more durability, looks better or why?

Any ideas?

Cheers,

Alex

[GTSBoy]

Um.....it's not lacquer.  It's the clear resin that makes it a composite material.  It's also smooth, weather resistant and paintable.

[Robocop2310]

3 hours ago, GTSBoy said:

Um.....it's not lacquer.  It's the clear resin that makes it a composite material.  It's also smooth, weather resistant and paintable.

That’s it mate. So these are the main reasons? Wouldn’t dry carbon fibre also be the same? It just looks a little funny in my honest opinion.

[Super Roo]

The resin is what actually sets the material in place. Without the resin you'd just have a carbon fibre fabric, which as you can imagine wouldn't hold its shape very well! The resin can either be added separately when the part is made, or it can be impregnated into the carbon fibre fabric. It's generally an epoxy resin of some kind.

[Robocop2310]

11 hours ago, Super Roo said:

The resin is what actually sets the material in place. Without the resin you'd just have a carbon fibre fabric, which as you can imagine wouldn't hold its shape very well! The resin can either be added separately when the part is made, or it can be impregnated into the carbon fibre fabric. It's generally an epoxy resin of some kind.

Thanks for answering my question clearly. I often think of carbon fibre parts as the dry stuff but I guess it makes sense without that resin CF parts would not be very durable.

[ossy]

There's different types of carbon fiber... It's known as wet carbon fiber if it's glossy and dry carbon fiber if it's matte/dull. The shine is resin as mentioned but it's applied differently for different properties and physical appearances.

 

Shiny carbon fiber is much cheaper. It's easier and much cheaper to make as it doesn't need to be baked within the weaves. This makes it weaker than dry carbon and heavier but gives it a nicer finish.

Non shiny (dry) carbon fiber is much, much stronger as the resin is baked within the weaves as it's being created. This is because it has less air bubbles trapped inside and less impurites this way but takes alot longer to make and therefor, costs alotmore. It also weights around 60-80% less than shiny carbon fiber.

I believe for high end stuff like some supercars and racecars, they actually use dry carbon fiber to make parts super strong and much lighter and then coat it in gloss or more resin to give it a nice appearance. Basically combining the two together.

Edited September 11, 2018 by ossy

[niZmO_Man]

dry = prepreg = you put it in/on a mold, cover with vacuum bag, vacuum and bake it in autoclave

wet = imagine laying fibreglass, but the glass is carbon

[GTSBoy]

Yuh, so dry isn't dry, because it is actually pre-wet.  You just don't add any more resin as you lay it up.  Watch Superfactories/Koensigeggeggeggegg Youtube videos etc etc to see how it's done.

[Robocop2310]

Thanks for educating me. I watched some videos as you guys suggested on YouTube and why the whole process is an art form no wonder CF (proper high quality ones anyway) are so expensive.