Has anyone tried doing this?

I'm currently toying with the idea of doing some vaccum bagged wings for my sailplanes, and thought, why isn't anyone bagging F3A wings?

Is it simply too hard? Or is it purely a production issue?

What gives?

They are!

Try the following links:

http://www.probuild-uk.co.uk/factshe...ining_wing.php

http://www.znline.com/content.php?la...nus=1061368108

AA

Ola Fremming has a great web page with an excellent artical on how to do Vacuum bagged wings(http://home.online.no/~ofremmi/HowTo.../VacuumBag.htm). Were you talking of balsa skinned cores which are vacuumed on, or a foam core with only glass vacuumed on like some of the competition gliders? Matt

I have been vacuum bagging my pattern wings for about 15 years. I use the vacuum pump and other items from AeroSpace Composites. I started out with the EZ-VAC Bagging Kit and as the pattern wings got bigger in the root chord had to purchase some of the 2 mil nylon bagging material instead of using the 18" wide bagging tube. West Systems 105 resin with the 205 Fast Hardener is thinned about 50% with denatured alcohol and brushed on. I checked out Ola Fremming's site and the only differences that I saw between our methods was the brushing on of the epoxy and what goes inside the bag. I bag the whole sandwich -- bottom offcut, balsa sheet, foam core, balsa sheet, top offcut. I am amazed at how little epoxy is needed -- the wood feels/looks just damp. Each layup gets a test for proof of good adhesion -- the strip that gets cut out for the aileron hinge line is pulled apart and invariably the foam splits down the middle and stays stuck to the balsa sheeting. It's a bit more trouble but the result is very good -- I don't remember the numbers anymore, but the panels will come out lighter from using less glue. It was a good investment and is a good technique.

Tom

Another option to what gets bagged...or no bag at all.

I'm thinking this should work even for a honeycombed wing, what do you guys think?

I have used vacuum bagging for honeycomb wings and it works just as well as normal foam wings. I had to think about it for awhile because I was concerned about the balsa being pulled into the honeycomb cutouts. however, because there is equal pressure on the entire outside envelope and foam shucks, there was no indication of any indentations over the honeycombed areas. Worked great.

Woodie

Sorry guys, I was actually talking about epoxy/glass/carbon skins on pattern wings.

The glider guiders have been using relatively high density foams (60lb) and skinning with epoxy and glass/carbon layups straight onto the wing, providing them with a glass smooth, pre painted wing.

Obviously considering we're not working with wings with 6% sections, we can go for lighter density foams, but is it possible?

It is possible, but the softer the foam core is, the thicker the skin has to be to give sufficient strength.
I think that you will find that the total weight will be significantly higher than for the foam core/balsa skinned wings. The alternative is to use hollow wings, i.e. sandwich construction.

Regards,
Magne