Here is the Look KG381 carbon fiber bike that I'm in the process of repairing. The drive side chain stay was cracked at the lug joint, as well as the seat stay at the brake bridge. In the pic to the left the chain stays just recived the last 4 of 9 structural layers of carbon fiber and the vacuum bag was just applied. The first 5 layers of carbon were applied and just the drive side chain stay was bagged to build the chain stay up to the same profile as the lug. The last 4 layers covered the lug entirely to the bottom bracket. The vacuum bag was sealed off on the down tube and seat tube just above the water bottle bosses and closed on the other side of the chain stay drop outs, the seat stays were unbolted and left out of this bagging process. I also had to insert the seat post coated with high vacuum grease to close off the seat tube and a small curved shim was bonded in place in the head tube to close off the down tube. A spacer was added between the dropouts to protect the chain stays from the massive force of the vacuum bag.
After 8 hours in the vacuum bag and my pump beginning to smoke, I turned off the heater and the pump and peeled away all the media to revieal this... It turned out perfectly. Just playing around with it the repared drive side chain stay is far stiffer than the factory side. I still have to sand off some small ripples from the peel ply and add a cosmetic layer of carbon before this is complete. I'll update this post with pictures of the seat stay as they become availible.
This bike should be on the road by the weekend.
-blonde fab