Light weight structural parts

Pressurized components are stronger than atmospheric, but when they loose pressure they loose strength. This idea maintains pressure even if hole develops in the pressurized component.
Fill a hollow pipe or other hollow component with pressure.  This stretches the exterior surfaces and moves the steel up the yield curve. 
while under pressure, fill the hollow piece with light, hollow glass beads (strong to 20,000+ psi external) that flow like water.  This will fill all internal spaces.  Mixed with the beads are a tiny amount of dry adhesive powder that cures at slightly above room temperature covers the beads.  Structure is sealed, cured, maintaining pressure.  After curing, the light weight interior remians under compression while skin remains in tension, even if leak develops.  This is ultra lightweightprestressed concreteturnedinsideout. Make anautomobile componentout ofthat. In bending, beadsact ascompression memberand skinacts astension member.  Willnot failby bucklinglike ahollow memberwould fail.  Ultimatefailure willbe whenskin stretchesbeyond elasticlimit,at leastan orderof magnitudehigher bendingstress.  a super light, high strength component.