Marine Exhaust Hose

 

It is not uncommon for smaller horse powered engines onboard to have a wet exhaust. A wet exhaust is where water is injected thru a spray ring into the exhaust system. This cools the hot exhaust gasses and enables the use of rubber hose further on downstream. Rubber exhaust hose is commonly manufactured with an internal wire that is wound like a spring to prevent the hose from collapsing when bent or when something is placed on top of it. Marine hose has the advantage over a metal exhaust in that it is flexible, easy to install and non-corrosive.

 

Marine wet exhaust hose from manufacturers such as Trident Marine® or Shields Marine® is manufactured to specific standards. One such standard is permeability. On the onset this might not appear an important standard, but one needs to remember that exhaust fumes, whether from an internal gas engine or a diesel engine, produce a deadly gas called Carbon monoxide during combustion. Carbon monoxide (CO) is an odorless, colorless gas and using a hose that is not rated for use as a boat exhaust hose could lead to Carbon monoxide leaking through the hose walls. Over time even a top quality marine wet exhaust hose will begin to deteriorate because of the age, heat and the corrosive nature of the exhaust gasses and water.

 

A common failure over time is the wire eventually starts corroding, or the inner part of the hose will separate from the wire and collapse causing restrictions in the exhaust and or the possibility of failure to contain the gasses. It is very important not to assume all exhaust hoses are equal.

 

An alternative to rubber exhaust hose is silicone exhaust hose. Silicone exhaust hose can withstand higher temperatures for a longer duration. Silicone exhaust hose is more expensive than the equivalent sized rubber hose. For comparison a 3 ½’ marine exhaust hose made of silicone is about 36% more expensive than rubber hose and it is also only available in specific lengths whereas rubber hose is sold by the foot and is available in much longer sections.

 

Boat Engine Hoses

 

It is not uncommon for an engine to use additional rubber hoses. These type hoses are often OEM supplied parts although many are available as after market from companies such as Sierra/Seastar®. It is also possible that some engines make use of a rubber hose that is replaceable with an on the shelf equivalent.

 

Exhaust Hose Accessories

 

Whether installing a new exhaust system, maintaining, or replacing an existing, there is always the need for additional parts such as hose clamps and exhaust protector valves. Hose clamps, even if they are manufactured from 316 stainless steel, will corrode over time, and fail. It is good marine industry practice to replace all hose clamps with new good quality stainless steel hose clamps from Scandvik® or Trident Marine® during installation. It is also recommended using two clamps on any fitting no matter the type of clamp being used.