Buoyancy Systems

Plasti-Fab PlastiSpan flotation billets are produced using expanded polystyrene with extra attention paid to water absorption and flexural strength properties. PlastiSpan flotation billets are produced in a standard size, with special sizes available for custom floating structures or boats.

Advantages of PlastiSpan flotation billets:

• PlastiSpan flotation billets are suitable for fresh or salt water and are unaffected by winter temperatures. Proper design methods for flotation devices exposed to winter weather should be employed to prevent or minimize mechanical damage caused by ice movement by extending skirt boards below water line.
  
  
• PlastiSpan flotation billets support 881 kg/m3 (55 lb/ft3) with a margin of safety, whereas wood, which is 20 to 40 times heavier depending on type, will support only one-third to one-half of this weight.
  
  
• PlastiSpan flotation billets provide low installation and maintenance costs, and is lightweight and easy to work with using conventional tools.
  
  
• PlastiSpan flotation billets provide no food value for marine animals. Growth of marine life on PlastiSpan flotation billets may occur in stagnant water, however, any topical growth will not impair the buoyancy of the billet and the growth can be removed with a wooden scraper. Where marine animals may chew out a space for a nest and cause settling, wrap the billets in 6 mm or 10 mm (1/4” or 3/8”) non-corroding wire mesh or construct the floating structure so that billets are placed right against the boards or against each other.
  
  
• Floating structures utilizing properly placed flotation billets exhibit excellent rebound characteristics with minimum rocking. PlastiSpan billets provide less resistance to breaking waves and are quieter than other types of flotation devices (e.g. drum floats).
  
  
• Damage to a billet is confined to a specific area and is non-progressive; each of the foam cells which make up the foam structure acts as separate flotation compartments.

Toughide Flotation Billets (Gasoline Resistant)
Toughide flotation billets consist of a PlastiSpan billet factory coated with 10 mm (3/8”) thickness of a tough, hard polyurethane foam. Toughide billets are resistant to abrasion and intermittent exposure to gasoline. Take care not to crack the coating when tightening fasteners through the billets.

Other Finishes
On request Plasti-Fab can coat PlastiSpan flotation billets with a number of other elastomeric finishes which can provide gasoline resistance or other properties to the billet.

Caution
PlastiSpan flotation billets are subject to damage by gasoline or other petroleum solvents. Where gasoline spills are expected, cover PlastiSpan billets with galvanized iron, aluminum, plywood or other suitable cover to below the water line. Skirt boards properly installed to below the water
line will protect the billet from random gasoline spills floating in the water. As an alternate, substitute Toughide flotation billets.

PlastiSpan flotation billets and Toughide flotation billets are combustible; this is not a concern in floating structures but during construction, normal fire precautions should be observed. Avoid open flames, welding torches and high intensity lamps. Fire extinguishers using water foam, carbon
dioxide or dry chemicals are all effective.