Stringer and Transom Systems

A properly designed and constructed stringer system provides structural integrity, stiffness and load-transference to the hull.

Polyumac’s Stringer Systems are engineered to be an integral part of the hull structure based upon the characteristics of the customer’s specific hull configuration and laminate schedule.  


Polyumac provides a LIFETIME GUARANTEE on our Air-Cell Transoms.   We guarantee that our Air-Cell Transoms will NEVER ROT, and will not fail when properly engineered, installed and laminated.   Our CNC-cut Transoms can be ordered separately or as an integral part of our Stringer Systems.


We provide full Engineering Design and Support Services for our Transoms and Stringer Systems. 

Key Features
  • Air-Cell foam won’t absorb water and will never rot
  • Quality. Our CNC cutting assures a precision fit every time
    • Underside of stringer mates to the dead rise of the hull skin
    • Insures proper location of transversal to longitudinal stringers,  can include or be notched for precise location of bulkheads
  • Designed using a range of densities to add structural integrity
    • High density foam can be added as an integral part of the stringer in areas subject to high loading
  • Structural foams used for strength and stiffness
  • Can include predrilled through-holes for wiring and piping
  • Can be integrated with our pre-cut transom
  • Labor saving. No cutting, shaping, or fitting at the customer location
  • Interlocking pieces enable the stringer to be
    • shipped on convenient sized cartons
    • handled easily in the shop and assembled in or out of the mold