7 Tried And True Firestop Products Enhanced For Modern Shipbuilding 

Sep 21, 2021 by Terry Mannion, Director of Marine Industry Relations 

Firestopping in ship building

It is no surprise to many of us in the Marine Industry that some shipbuilding processes are steeped in “old school,” traditional shipbuilding methods and products. A common method of firestopping uses gooey stuff forced around cables and pipes in bulkhead openings and is referred to as monkey $#+!

New innovations are rapidly changing the shipbuilding industry by providing better alternatives to traditional products and practices.

STI Marine Firestop products are a good fit into this new era of shipbuilding solutions.

STI Marine Firestop MPU Firestop Putty

MPU Firestop Putty


STI Marine is leading the way as the trusted leader in marine firestopping. Our “NEW school” MPU Marine Firestop Putty is designed to seal small to medium-sized cable openings in fire-rated divisions. This non-hardening, moldable compound is now available as an extruded roll making it easier to handle with less waste within a resealable pail and in pliable bricks. 


STI Marine Firestop Sealant

Marine Firestop Sealant

Another widely used firestop product is MFS Marine Firestop Sealant. This advanced, durable hybrid polymer elastomeric sealant prevents the transmission of water, air, smoke, and gases. Maintenance-free and easy to install, this sealant is ideal for applications when watertight is a requirement. Additionally, MFS Marine Firestop Sealant is resistant to aging and weathering, and it is also non-corrosive and nonconductive. It is commonly used for interior or exterior pipe and cable applications in decks and bulkheads.  


Marine cable transit systems haven’t changed much since their introduction in the 1950s, until now. STI has reengineered and enhanced a full line of firestopping cable transit systems to support today’s modern shipbuilding evolution. Our self-sealing and self-contained devices make up the full line of EZ Path Marine Cable Transit products. The Marine EZ Path Cable Transit offers zero maintenance in the event of cable moves, additions, and changes (MACs) over the vessel’s lifecycle without putty, sealant, or compression blocks.

STI Marine Firestop EZ Path Cable Transits

EZ Path Marine Cable Transits


STI Marine Firestop Snap-Seal Cable Plugs

Snap-Seal Cable Plugs

Snap Seal Cable Plug seals small cable and tube installations through steel and aluminum divisions. The two-piece design allows it to snap around existing cables. Marine Snap Seal Cable Plug can be both an A-60 fire boundary above the waterline and a weather-resistant plug for exterior applications. 



With the introduction of non-metallic pipes in ship piping systems onboard cruise ships, STI Marine has led the way with firestop collars incorporating intumescent technology that rapidly expands – crushing and knotting the plastic pipe as temperature presents a threat during a fire event.

STI Marine Firestop MFC Collar

MFC Collar

The MFC Collar is a factory-manufactured device used as a pipe penetration seal in fire-rated bulkheads and decks. It is comprised of a stainless steel body with a mild steel flange for easy weld attachment to the division, and the split design allows for quick installation around existing pipes. 


STI Marine Firestop MFC-W Collar

MFC-W Collar

The MFC-W Collar is a watertight, intumescent pipe collar used as a penetration seal in fire-rated bulkheads and decks. It is comprised of a stainless steel body with a mild steel flange for easy weld attachment to the division and incorporates a rubber grommet or the use of MFS sealant to ensure water tightness.  


STI Marine Firestop MFC-G Collar

MFC-G Collar

The MFC-G Collar is an intumescent pipe collar used as a FRP/GRE/GRP pipe penetration seal in fire-rated bulkheads and decks. It is comprised of a stainless steel body with a mild steel flange for easy weld attachment to the division and can provide water tightness with a quick application of MFS Sealant.  


STI Marine Firestop MFC-T Collar

MFC-T Collar


The MFC-T Collar is a pipe collar designed to protect and isolate transitions between plastic and metal pipes or scuppers in fire-rated divisions.  



STI Marine MPACT Pipe and Cable Transit

MPACT Pipe and Cable Transit

The flexibility and simple installation of STI MPACT is sought after by several types of ship owners and shipyards across various markets including military, commercial, oil & gas, cruise and workboats. Easily installed as a fire boundary or a watertight fire boundary, MPACT is the “go-to” solution for repairs, refits, modernization, and new construction projects.


STI Marine Firestop Pillows

Marine Firestop Pillows

Recent fires within the shipyard industrial base have forced a re-evaluation of fire protection. A three-pronged approach of personnel training, portable detection and suppression, and temporary firestop has caught the industry’s attention. STI Marine “pillow” technology is at the forefront of this effort. Pillows temporarily seal open penetrations and scuttles while work is underway in the yard and on the ship. 



As the demand for STI Marine firestop grows in the shipbuilding world, STI is currently working with SSI. Their ShipConstructor 3D modeling software is a powerful platform for the design, engineering, and construction of ships and offshore projects. STI will soon be able to offer a library of our firestop products for easy import into our customers designs as part of the new SSI 2021 R1.1 release.


Contact STI Marine Firestop to discover our full range of marine applications to help determine what you need to successfully firestop your next shipbuilding project.

Check out our full line of Marine Firestop Products in action!


STI Marine Firestop Training