Author Topic: Carbon Fiber 1987 (Read 785 times)

Leester · « **on:** November 22, 2006, 03:01:14 PM »

While going through the Jan. 1987 issue of FM in the "Fifth Column" by Dave Platt, he was discussing uses for the then new Carbon Fiber. Some of the suggested uses where putting on the back of wing leading edges, top and bottum of wing spars, inside leading edge sheeting between ribs to stop splitting, and between trailing edge sheeting.
He states using .007 or .014 C/F would allow you to reduce wood size and weight and not lose strength. We use C/F on fusalage construction, but I haven't noticed these on wing construction like he discribes. Did they not work ? Were they tryed in C/L ? Were they practical ? any comments ?

phil c · « **Reply #1 on:** November 22, 2006, 03:20:32 PM »

they work, they are practical. The main thing is taking the time and effort to determine just how much reinforcing to use, where to use it, and how much the wood can be reduced to compensate for the weight. CF is strongest when bedded in epoxy, so getting the right ratio, getting it cured properly, and in the right place is not trivial.

A good example of CF reinforcement is Randy's nose construction- two layers of 1/8 in. medium balsa with a layer of CF veil in between and glass or CF veil on the outside. Stiffer and stronger than anything you can do for the same weight using plywood and glass, but it took quite a bit of testing to get it right. Not too many people want to put the hours into a stunter and find out that the wing folds because the CF delaminated!!!

Bill Little · « **Reply #2 on:** November 22, 2006, 05:01:07 PM »

Using strip CF in .007 thickness is a great way to strengthen wing spars, etc.. I can see no real advantage to using CF matt/veil for those purposes, though.

I face the TE, and "double" the spar caps, on I-Beam wings with .007 CF strip applied with medium or slow CYA. MAkes a difference and not much weight is gained. I guess what I'm trying to say is that you cannot get the same strength gain using a "wood" method of some sort........

Author Topic: Carbon Fiber 1987 (Read 785 times)

Leester

Carbon Fiber 1987

phil c

Re: Carbon Fiber 1987

Bill Little

Re: Carbon Fiber 1987