Bill3558 Posted October 26, 2020 Report Share Posted October 26, 2020 Took my wife for a ride today. First time she’s flown with me since mid 80’s. Nice flight, she loved it. When I got the plane back in the hanger I hooked up the battery charger and shortly started smelling something burning. I took the cowling off and saw smoke coming up from the positive charging wire that hangs down. The clip was touching the cowling it was smoking at point of contact. I didn’t think carbon fiber was a conductor, but apparently it is. I hate to think what would have happened if I didn’t catch it. The whole plane might have burned up. I’ll put some rubber insulation there but BEWARE! Quote Link to comment Share on other sites More sharing options...
sandpiper Posted October 26, 2020 Report Share Posted October 26, 2020 I've never givin this much thought. But I will now. My plane is always on a charger when at home. With hangar attached to house I sure don't need a hangar fire! Thank you for posting. Quote Link to comment Share on other sites More sharing options...
Tom Baker Posted October 26, 2020 Report Share Posted October 26, 2020 Yes, be careful in placing the clip on the wire so it doesn't touch anything. Also I quite a few with the little rubber tube that is supposed to cover the end of the wire wile not chargine on the ground missing. Make sure it is in place, and slid over the exposed wire while not on charge. Quote Link to comment Share on other sites More sharing options...
Bill3558 Posted October 26, 2020 Author Report Share Posted October 26, 2020 What’s weird is that at other times I know there was contact with the cowling and it wasn’t an issue. Today it somehow found a path to ground and burned. Quote Link to comment Share on other sites More sharing options...
Jim Meade Posted October 27, 2020 Report Share Posted October 27, 2020 Carbon fiber is a conductor. Many of the coatings are not. I can touch two places on the skin of my CTSW and get infinite resistance. I can touch the inside of two holes through the skin and get conductance. Quote Link to comment Share on other sites More sharing options...
FlyingMonkey Posted October 28, 2020 Report Share Posted October 28, 2020 IIRC carbon fiber is also flammable, but the epoxy resin is at least "somewhat fire resistant". Quote Link to comment Share on other sites More sharing options...
Tom Baker Posted October 28, 2020 Report Share Posted October 28, 2020 1 hour ago, FlyingMonkey said: IIRC carbon fiber is also flammable, but the epoxy resin is at least "somewhat fire resistant". I think it is the other way around. This article talks about a company that is recycling carbon fiber by burning off the polymers (resin). https://www.theguardian.com/sustainable-business/2017/mar/22/carbon-fibre-wonder-material-dirty-secret Quote Link to comment Share on other sites More sharing options...
FlyingMonkey Posted October 28, 2020 Report Share Posted October 28, 2020 4 minutes ago, Tom Baker said: I think it is the other way around. This article talks about a company that is recycling carbon fiber by burning off the polymers (resin). https://www.theguardian.com/sustainable-business/2017/mar/22/carbon-fibre-wonder-material-dirty-secret I could totally have that backwards. I just remembered one component was flammable and the other was not. Quote Link to comment Share on other sites More sharing options...
AGLyme Posted October 28, 2020 Report Share Posted October 28, 2020 either way, the takeaway is that it burns... that’s good to know. When I was a kid... I worked at Plymouth MA airport washing planes, sweeping hangar floors... One morning I watched an old crop duster helo start to spin in the distance and ultimatey crash into a nearby cranberry bog. A pilot and I jumped into an Enstrom and flew the 1/2 mile and landed near the crash site which was a ball of colored flames. The pilot was leaning against a tree smoking a cigarette James Dean style and looked at us and shrugged... what a badass. I learned that day that magnesium, used in the skin and other aircraft parts, liked to burn and burn hot. let’s hope that C fiber isn’t as bad as magnesium was/is. Quote Link to comment Share on other sites More sharing options...
Tip Posted October 28, 2020 Report Share Posted October 28, 2020 Most trickle chargers come with a pigtail so that you can hardwire it to your positive and negative. With this, you have a coupler that eliminates any mix up when connecting the charger. The coupler also provides some insulation. Quote Link to comment Share on other sites More sharing options...
Skunkworks85 Posted October 28, 2020 Report Share Posted October 28, 2020 1 hour ago, AGLyme said: either way, the takeaway is that it burns... that’s good to know. When I was a kid... I worked at Plymouth MA airport washing planes, sweeping hangar floors... One morning I watched an old crop duster helo start to spin in the distance and ultimatey crash into a nearby cranberry bog. A pilot and I jumped into an Enstrom and flew the 1/2 mile and landed near the crash site which was a ball of colored flames. The pilot was leaning against a tree smoking a cigarette James Dean style and looked at us and shrugged... what a badass. I learned that day that magnesium, used in the skin and other aircraft parts, liked to burn and burn hot. let’s hope that C fiber isn’t as bad as magnesium was/is. Carbon Fiber is not flammable, The Resin is. In fact during composite testing the only accurate way to measure matrix vol vs resin vol (ratio) is to measure the weight of sample, then burn off all resin, and then measure the weight of remaining matrix. FYI, there is a special fire extinguisher for metal fires, most people are familiar with a class A/B/C fire extinguishers. But there is a little known class D that is for metal fires. These are VERY expensive, I only know how expensive these are, because in college, A member on my FSAE team was machining on a magnesium wheel, and the it burned through the mill knee before they wheeled the class D extinguisher over to put it out. Quote Link to comment Share on other sites More sharing options...
GlennM Posted October 28, 2020 Report Share Posted October 28, 2020 In my experience, most metals burn given the right atmosphere. Titanium is self-oxidizing like magnesium. So you have to take the heat away or interrupt the chemical reaction somehow. Roger should know, he was a fireman. I watched Backdraft twice, so I am an expert, too. Quote Link to comment Share on other sites More sharing options...
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