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So this is just for my edification. I recently made wingtip fairings from fiberglass and the result was satisfactory, and for me quite a bit easier than fighting with aluminum. Carve a mold, wrap fiberglass, apply epoxy. I made the fairing with 3 layers 6oz E cloth and Stewart system. It's at least as stiff as the aluminum version was. S cloth might well be better.
I've always heard fiberglass is heavy. So I weighed the new fairing and compared to my 020 aluminum version. The weight is nearly identical. So I'm not understanding the "fiberglass is heavy" statement. And there is no nailing or drilling and riveting it to the wingtip bow.
Why are there not more fiberglass leading edges? I know it's been done several time but have having trouble finding real data.
With fiberglass you don't have the problems of aluminum coefficient of thermal expansion vs wood, no nailing, it's easy, and not really expensive unless you have to use carbon fiber. Given that you're just going to pull fabric over it you don't really have to spend much effort finishing the part, which is where a ton of the fiberglass effort goes.
I have heard anecdotal evidence that the nose ribs can start "printing" on a fiberglass leading edge. This is likely due to fabric pulling pulling on the unsupported length between ribs. Over time fiberglass creeps. It seems to me that it would be easy to transfer some load from the "vertical" portion of the leading edge to the horizontal portion and address the sag. Of course the devil is in the details.
In the Charger's case you have non structural leading edges. The plans call for 016. This dents if you sneeze on it. It's easy to form, but I've ruined a couple of pieces by being careless. So I decided to go with 020 which is kind of a beast to form and work with. And you have nails and thermal buckling to worry about.
Just curious. And yes, I know lots of people believe plywood is best.
I've always heard fiberglass is heavy. So I weighed the new fairing and compared to my 020 aluminum version. The weight is nearly identical. So I'm not understanding the "fiberglass is heavy" statement. And there is no nailing or drilling and riveting it to the wingtip bow.
Why are there not more fiberglass leading edges? I know it's been done several time but have having trouble finding real data.
With fiberglass you don't have the problems of aluminum coefficient of thermal expansion vs wood, no nailing, it's easy, and not really expensive unless you have to use carbon fiber. Given that you're just going to pull fabric over it you don't really have to spend much effort finishing the part, which is where a ton of the fiberglass effort goes.
I have heard anecdotal evidence that the nose ribs can start "printing" on a fiberglass leading edge. This is likely due to fabric pulling pulling on the unsupported length between ribs. Over time fiberglass creeps. It seems to me that it would be easy to transfer some load from the "vertical" portion of the leading edge to the horizontal portion and address the sag. Of course the devil is in the details.
In the Charger's case you have non structural leading edges. The plans call for 016. This dents if you sneeze on it. It's easy to form, but I've ruined a couple of pieces by being careless. So I decided to go with 020 which is kind of a beast to form and work with. And you have nails and thermal buckling to worry about.
Just curious. And yes, I know lots of people believe plywood is best.
