Hi Adrian,
Thanks for the post. We'd be very pleased to work with you, answers to your questions as follows:
1. I wish to "skin " a wing with CF that has been professional manufactured from a foam core that has a thin wood veneer. The wing is to be fitted to a speed hill climb car. The purpose of the skin is to provide some protection to the wing. What would be the best way to finnish the surface after the vacuum process.
There are a number of ways you can do this and all of them are capable of yeilding good results, probably the simplest method would actually be to just wet-lay carbon and epoxy onto the surface of the wing (doing one face at a time) and then wrap the wing with pulled-tight release film. Because the release film is see-through you can see any air bubbles or imperfections underneith the film and use a squeegy to shepherd the bubbles out to the edges. The release film is so none-stick that when the resin is cured you can just untape the edges (where you've pulled it tight onto the underside of the wing) and it will just fall off, usually leaving a really nice smooth glossy surface. This technique will only work if the film can be pulled tight and so if the wing is curved with a convex side and a concave side then you might have a problem pulling the film tight on the concave side.
If you use resin infusion or a conventional vacuum bagging stack then you'll be left with a 'peel-ply' finish on your part which would mean that you'll need to lacquer or re-coat the part to give it a smooth glossy carbon fibre finish instead of the textured finish that the peel ply would leave. A single coat of lacquer would probably do the trick though and spraying lacquer onto a peel-ply finish does not have any of the difficulties associated with spraying gloss finished carbon parts. I think for adding a single (or perhaps double) skin of carbon fibre to the wing, under the assumption that you'll need to lacquer it afterwards, that out of the two vacuum bagging would be the way to go. The only reason for this being that, because you're not working with a mould you would have nowhere to position all of the infusion aparatus (spiral, connectors etc.). For the vacuum bagging stack itself you could even try just using the bag alone (no peel-ply, no breather, no perforated release film). What you'll effectively have if you do this would be the same as the release film method but without the problem of not being able to pull the fulm tight on the concave side.
2. I also what to construct some "end plates" ( approx 0.5 M x 0.8 M ) from CF/core/CF sandwich. I was considering doing this between two plates of glass ( I'm looking for a good finnish on both faces ). Had a go at this using wet lay up / clamps....not much success.
Double sided carbon, with a good finish, can be tricky. You should find that you can do this if you vacuum press the panel between the two sheets of glass, rather than glamping it. This is how we make our foam core panel. Wet-lay carbon onto each sheet of glass using a bristle roller to try to ensure as few air bubbles as possible in the laminate then lay the core onto the wet carbon and then turn the other sheet over to lay it on top of the other, facing down. Finally, vacuum bag the whole lot at about 70% vacuum (if the bottom sheet is larger than the top sheet it should be possible to tape the bag over the top sheet and to the bottom sheet, rather than envelope bag the whole lot).
3. Finally some time in the future i would like to have a go at wing ( for the same speed hill climb car ) totaly out of CF. This would use two molds for the top/bottom of the wing and returns to enable good bonding between the halves.
OK, great. There's a few people on this forum who have made wings using this method. We have also manufactured wings commercially so we can give you any input or advice you need. Resin infusing the top and bottom skins first is the way to go.
I hope this helps and look forward to working with you.
Best regards, Matt
Matt StathamEasy Composites / Carbon Mods - Technical Sales