Originally posted by bachsta
ok just wondering because pml say you can squeeze drop or throw a quantom airframe on the ground and it wont break or crease like paper and phenolic. also what is the strongest body tube material when fiberglassed? and why does fiberglass make things so much stronger?
It's the glass plus epoxy that makes it stronger. Epoxy holds stuff together real well. The more surface glued, the more bond you get. The glass weave or matte provides an enormous amount of surface area, in the form of lots of fibers close together, but with enough space between them for epoxy to flow, so that all the epoxy gets to hold to something. Having this in contact with a surface means having the epoxy glue every bit of the surafce to every other bit into a solid mass. Glass+epoxy on the otuside also makes it much more resistant to impacts and abrasion.
Kevlar is even more resistant to impact and abrasion, but it's a little heavier. Carbon is lighter, but not as resistant. All work on the same principle, epoxy flowing into the weave/fibers. In fact, tubes are made of one or two of these three things together plus epoxy, without being on the surface of an underlying tube at all. Glass plus epoxy is so strong that it doesn't need the tube, so if a tube is there, it's very very strong. Without a tube in there, it's much lighter than with. That's how and why all-glass or carbon birds are made.
The strongest glassed tube would be the tube that was strongest without it, plus the glass+epoxy. I have a feeling that a paper Estes type tube glassed would be stronger than the strongest unglassed tube. That's just a guess though. Quantum might be as strong.
A glassed tube weighs more though. There's a performance/strength trade off. The best policy is probably to figure how how strong you need it to be and go with the lightest tube that's strong enough. There's not much fun in building and flying a rocket that's built like a brick and flies like one.