Lockers and hatches, commonly found on boats and caravans, require a seal to prevent water ingress. There are many different types so you should considering the following factors when choosing a sealing solution:
Trueness: When the lid is closed, there should be an even gap all the way around the hatch so that there is an even compression on the seal.
Surface: The type of sealing surface such as knife edge or flat surface will influence the style of sealing solution you can use. Sponge seals and rubber extrusions can be bonded onto flat surfaces, but clip on edge trims will be required for lockers and hatches with flanges or edges.
Compression: You should aim to compress your chosen seal by approximately 30%. This helps provide a watertight seal whilst preventing compression set or damage. It may be necessarily to fabricate ‘stops’ around the edge of the hatch to ensure that the lid does not compress the section by more than 30% when closed.
Weight: The weight of the hatch and the number of fixings holding down the hatch will influence the size of seal required. Heavy hatches and those with a large number of fixings should be fitted with larger seals to reduce the risk of damaging the seal when under compression.
Type 1: Sponge Seals
Sponge seals can be used on lockers and hatches which have flat surfaces. These sections would need to be bonded onto the surface with a high quality adhesive if no pre-supplied adhesive backing is present on the seal.
Our sponge seals are manufactured from a closed cell sponge so do not absorb water. They are available as rectangular strips or different shapes and sizes. Depending on the force of compression, you may decide on using a sponge strip or section with hollow centre. Sponge sections with hollow centres require significantly less compression than ‘solid’ alternatives.
We advise against compressing sponge seals by more than 30% so suggest that ‘stops’ are fabricated around the edge of the hatch to ensure that the seal is not under too much compression. Sponge seals under pro-longed and excessive compression will result in compression set.
View our range of Sponge Seals.
Type 2:Rubber Extrusions
Rubber extrusions are manufactured from a solid rubber, similar to the hardness of a car tyre. As these profiles are harder than sponge alternatives, they are suitable for heavier hatches with larger closing forces. They will need to be bonded onto a flat edge using a high quality waterproof contact adhesive.
View our range of P Sections and Tadpole Sections.
Type 3: Interlocking Rubber Extrusions
It is possible to interlock two rubber extrusions by attaching one section onto the base and one section onto the lid. Interlocking sections are recommended when you need to significantly reduce the change of water ingress.
These rubber extrusions will also need to be bonded onto a flat edge using a high quality waterproof contact adhesive.
Type 4: Clip on Edge Trims
Clip on edge trims are commonly used as seals on boat hatches. They can also be used on doors, lockers, enclosures and cabinets. These sections consist of a metal reinforced clip on edge trim with sponge sealing bulb on the top or side. They are available in a range of sizes depending on the thickness of the panel they will be fitted onto and required size of sponge sealing bulb.
These sections should be fitted onto an edge so that bulb is compressed when the lid is closed. We recommend that the sponge sealing bulb is only compressed by approximately 30%. This is to ensure that excessive compression does not damage the seal and cause compression set. For example, if you have a gap of 10mm, we recommend using an edge trim with a bulb diameter of around 14mm.