CF Cloth Weight

[mml4]

I just purchased some carbon fiber cloth to do an inlay on a new never drilled/molested Prather Deep Vee 40. I bought a cloth kit from CJ Composites which included the cloth and the resin. I ordered the Carbon Fiber Cloth Fabric - Unidirectional - 12K – 19 oz. I chose this material because I felt it would be easier to put in one layer of heavier cloth as opposed to two layers of the lighter cloth.CJ also advises that unidirectional cloth is stronger than the other variety.Two layers of the lighter cloth will be 24 thousandths thick plus the weight of the resin while the cloth i purchased will be 30 thousandths thick plus the weight of the resin. I figured the final weight would be about the same because two layers would take more resin. I also assume the single layer of heavier cloth will be at least as strong as two layers of the lighter cloth.

I have not done the inlay as yet- If anyone has any advice as to why I shouldn't go ahead please let me know.
Thanks,
Marc

[NativePaul]

Being unidirectional it will only add stiffness in one direction, and being so heavy it will be a pain to lay if you need it to bend in that direction. If you are OK with that, it will be much stiffer than woven cloth of the same weight in your chosen direction, and one thicker layer is usually much cheaper than multiple thinner layers.

The number of layers has little relevance to the weight of the finished product, the weight of the cloth and the technique used to lay are the primary variables. Rough figures here, but a well squeegeed wet layup should be in the region of 100% of the cloth weight in resin, a vacuum bagged lay up should be about 60% of the cloth weight in resin, a vacuum infusion layup about 50%, and pre-preg about 40%.

[grsboats]

12K is really heavy and can be a pain countouring sharp edges.I've been making my riggers with 3K (maximum) with great results of resistance but I'm not saying that can't be done too. Gill

[mml4]

Thanks for responding to both you gentlemen!
I am a little intimidated with regard to this inlay project. Let me ask what CF cloth is generally considered the standard in terms of type (plain,unidirectional,twill etc),weight,and number of layers. I would of course like to get by with doing only one layer if I can. If doing two layers of a lighter cloth can you do one first and let it cure followed by the second or must both be done simultaneously.
I really want to get this right,
Marc

[grsboats]

You're welcome Marc.I use to make my own riggers using four to five lawyers of thin c.f. cloth from 1k to 3k depending on the size of boat but accordingly to my experience you better off in this case of reinforcement use two thin laywers of lighter cloth hand laid up consecutevely with no worries.Gill

[jcald2000]

5.8 to 6.0 oz. per layer.

[NativePaul]

I use 180-220gsm cloth depending on what the best price is when I buy, which is around 7 oz but a meter is a bit bigger than a yard so probably the 5.8-6 oz mentioned above. Generally I buy glass in plain weave but aramid and carbon in twill as they are much stiffer than glass and I need as much help draping into corners as I can get.

[dasboata]

The 3000K weave is what I use & lots others ,,the mat does not have the strenght of the cloth ! The cloth has intersecting 90* angles,,which make it a stronger,, mat has no defent shape it is random fibers held together with some kind of binder