Fluid tight blind fasteners and methods for fastening

A blind fastener comprising:

• a sleeve comprising:
• a first sleeve end comprising a first inner surface,
• a second sleeve end comprising a second inner surface,
• a third inner surface intermediate the first inner surface and the second inner surface, wherein the sleeve at the third inner surface has a variable wall thickness configured to initiate formation of a bulb on the sleeve to apply a compressive force against a structure after installation of the blind fastener and form a fluid tight seal between the blind fastener and the structure, and
• an elongate portion extending from the first sleeve end to the second sleeve end,
• wherein the first inner surface, the second inner surface, and the third inner surface define regions of a sleeve cavity extending into the sleeve from the first sleeve end toward or to the second sleeve end;
• and
• a pin configured to be at least partially received by the sleeve cavity, the pin comprising:
• a first pin end portion configured to receive a torque,
• a second pin end, and
• a shank extending from the first pin end portion to the second pin end, the shank comprising threads, wherein the threads are configured to form threads on the second inner surface of the sleeve and form a fluid tight seal between the pin and the sleeve,
• wherein the second inner surface and the threads of the shank are configured such that, after installation of the blind fastener, a length of engagement between the second inner surface and the threads of the shank is no greater than 2 times a minor diameter of the threads of the shank, and the threads of the shank extend uninterrupted from the second pin end over at least the length of engagement.