Abstract: Composite blind fasteners are disclosed, formed of a woven composite tube and a mandrel mounted within the tube. The mandrel has an encapsulation member mounted at its inner end, e.g., in the form of an O-ring, containing a first reservoir of curable resin and a second reservoir of activator for curing the resin, the two reservoirs being separated by a fracturable membrane. When the mandrel is pulled through the tube, it applies pressure to the O-ring housing the reservoirs, causing fracture of the membrane separating the reservoirs and resulting in mixing of the resin and activator. As the mandrel is pulled, a bulb of the resin mixture is formed against the substrate or structural component, and on curing of the resin, the resulting hard resin bulb locks the fastener in place on the substrate.