vac bagging wings

[mr_wood]

Can anyone explain to me what the advantage of vaccum bagging composite wings rather than just putting them back in the core outer and putting some weight on them ?

Thanks

Tim

[TThroop]

More consistent pressure for one thing. Also, what kind of foam are using and what type of finish are you doing? If you are putting plywood or balsa over white foam, then you need to apply approximately 4psi to get a good layup. If you are bagging a 3 meter thermal ship, then you have approximately 400 sq in per wing half. If my calculations are right, then you need approximately 1600 lbs. I quess you could park the front wheels of you compact car on the top of the beds. It gets worse if you are using blue foam, you need approximately 20psi.

Terry Throop ;)

[Ollie]

When you weight down skinned cores in their beds the force is applied vertically. When you vacuun bag, the force is applied perpendicular to the wing surface. The biggest difference is near the leading edge where weighting is least effective but needed most to bend the skin.