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Hatch Seal Product Builder

Home  »  Rubber Extrusion and Rubber Seals  »  Weatherproof Trim-Seals  »  Hatch Seal Product Builder

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About This Boat Hatch Seal

Trim-Lok’s Hatch Seal is a specially formulated compound rubber that provides a watertight seal and stops leaks. This bulb seal also helps minimize sounds and vibrations that may occur on moving boats. 

Boat hatch seals are available in two sizes to meet your application needs:

  • • 11B – 3/8” bulb
  • • 12B – 15/32” bulb

Choose from a variety of edge thicknesses, ranging from 1/6” to 3/32” and two bulb location options. To learn more about our watertight seals, explore the FAQs below.

Bulb Size *

*Price breaks, where applicable, will be reflected in cart*


For volume pricing above 5,000 feet, please contact Trim-Lok at 888-874-6565

Price: Build Your Part for Pricing

Why do I need a rubber hatch seal?

Boat interiors can get wet from ocean spray and washing. Keeping that water from draining into storage lockers and other secure spaces is essential to maintaining the lifespan of your marine vehicle and its storage units. 


Boats can also have an annoying rattling sound that happens when there is space between parts of the hatch. Although most new boats feature watertight marine hatch seals that seal out water and help reduce annoying rattles, many older boats weren’t manufactured with these seals. Or, if they did, the boat hatch seals may have worn out over time.
To keep the boat interiors dry and secure, old or missing gaskets can be replaced with rubber hatch gaskets. Specially formulated to promote a water-tight seal between the hatches and storage bins in your boat, our bulb seals are the perfect solution to keep your storage space protected from water intrusion and damage.


Why should I use Trim-Lok’s rubber hatch seals?

Intended to replace old gasket material that’s cracked or no longer preventing the hatch from leaking or rattling, the rubber and plastic components of our boat hatch seals are guaranteed to hold up in highly aggressive environments. Trim-Lok’s trim seal products are a simple way to create a finished edge and protect a wide range of applications from the elements.

More specifically, Trim-Lok’s line of hatch seals for boats are non-moisture absorbing and resist salt water and oxidation. The closed cell foam seals out moisture, weather, sound, and fumes. Whether you’re concerned about water damage or are annoyed by constant rattling, our marine hatch seals are the perfect solution.

How do I install watertight hatch seals?

Installation of boat seals is easy:
  1. 1. Clean the edge thoroughly using a solution of one part isopropyl alcohol and one part water with a new, clean rag.
  2. 2. Cut the seal to the desired length for your application, allowing a small amount of extra material.
  3. 3. Simply press the hatch seal onto the edge using a stuffing motion (do not pull) and ensure the edge trim and metal clip are fully engaged.

These bulb seals can be purchased with an optional butyl adhesive sealant to provide extra adhesion and a stronger seal. For information about purchasing rubber hatch seals with butyl adhesive sealants, contact a sales representative.

Although many mistakenly believe that a higher compression rate results in a stronger seal, our bulb seals are designed and engineered to work best at 25-40% compression of its original height, with 25% being optimum. If you compress it more than that, its life and serviceability will be limited. When building your part, be sure to choose the bulb size that correlates to a 25% compression rate for your application.

With easy application, a strong grip, and excellent resistance to ozone, water absorption and sunlight aging, there are plenty of product highlights that set Trim-Lok’s rubber hatch seals apart from other options available on the market. If you’re looking for a durable marine hatch gasket that will protect your boat from water damage and prevent unnecessary rattling, look no further than Trim-Lok. Find an international distributor or contact a sales representative today to purchase a high-quality boat hatch seal.

To view our entire catalog of products, download a copy, or request a free copy be mailed to you.

Boat hatch seals catalog page 22

Description Trim-Lok Hatch Seals are a specially formulated compound rubber that provide a watertight seal and prevent leaks. Perfect for marine applications, our boat hatch seals ensure anything in your storage space stays dry and protected from the elements. Watertight seals are available in various sizes and thicknesses, as well as bulb location options. Trim-Lok is proud to manufacture quality EPDM sponge rubber hatch seals that meet your specific requirements.
Resistance to
  • Ozone – Excellent
  • Water Absorption – Excellent
  • Sunlight Aging – Excellent
  • Low Temperature – Good
General Temperature Rating -20ºF to 158ºF
Outer Coating Material Poly Vinyl Chloride (PVC) 85 Durometer Shore A
Internal Metal Clip Materials
  • Aluminum - 3004 H38P
  • Steel - CRS SAE 1010, Rockwell B ,75-85 Durometer
Flammability &
Code Compliance
Bulb Material Custom-formulated EPDM sponge rubber bulb
View the Hatch Seal Spec Sheet
Radius diagram of watertight bulb seal for boat hatch
Part Number Top Bend Radius Inside Bend Radius Outside Bend Radius
12B100X3/16A 3.00" 1.50" 1.50"
12B100X3/16C 3.00" 1.50" 1.50"
12B100X3/16E 3.00" 1.50" 1.50"

How to Install Trim Seals

Watch the video to see a demonstration and learn how to install trim seals.