Adventures in Raw Water System Maintenance! – By “Dude With a Problem” (Bosley)

Not really…. but I’m sure it would be a riveting read!

Let’s face it… a “boat” these days is much more than just a hull that floats… a LOT more.  

My first boat was an old, decrepit aluminum jonboat that I dug out of a refuse heap in the backwoods of Virginia’s Dragon Run river. It was a hull that floated (mostly)… and not much more. I couldn’t believe someone had abandoned it… I mean, it still floated (mostly)!  I was 13, and I had a vision for it! 

I graced that craft with as many modern technologies as a 13 year-old could afford between my weekly allowance and the money I earned cleaning the floors at my mother’s laundromat… technology like a wooden paddle from a thrift store, a battery powered lantern and a rope with an anchor (ok, it was actually just a cinderblock from the local hardware store)… and it was beautiful.  

That first boat set in motion my love for the water, and it’s not an embellishment that it set the stage for nearly everything I have achieved in life… but that’s a story for a future PHIBER post.  

Now back to the point of THIS mental dump…

Unlike that first boat back in the early 1980s, my current vessels have systems that are significantly more complex… they are modern marvels of transportation that include creature comforts, ergonomic conveniences, life-preservation technologies, safety gear, complex control and navigation platforms, power generation and distribution networks, engine performance apparatuses, vessel stabilization systems, and so much more… And yet, with all the advancements in technology, many of these systems are still dependent on simple physics to operate.  

Yes, you read that correctly…

Since the early 1900s, the use of abundant seawater to cool critical systems has allowed us the freedom to roam the oceans in vessels ranging from military to recreational. Seawater, or “raw water”, is sucked into a plumbing network via a pump, pushed through hot equipment collecting heat, and then evacuated back overboard to the sea, carrying the heat out with it. This simple concept keeps operating temperatures within the limits of their system’s design… “simple physics”.

Having personally crossed oceans on everything from Expedition Yachts to Ocean Sailing Catamarans, I get just how important the role of cooling seawater is aboard boats. The advent of raw water cooling networks can be tied directly to the shift away from boilers toward mechanized marine propulsion (fuel-driven engines) over 100 years ago, but despite nearly 100 years of advancements in design and technology on boats, the raw water networks that support these critical systems are nearly the same design as they were back then; only the invention of the sea-strainer in the late 1940s is notable in the history of advancements in raw water system design. I know that’s hard to believe, but have you looked at your own raw water systems??  After 40 years of boating and 4 years of research to alleviate the torture of maintaining my own raw water networks, I’m pretty sure I’m right about that…

That said, I appreciate the simplicity of using seawater for cooling… Oddly, I’ve become a bit of a geek with regards to raw water systems, having designed and built many cooling networks over the years for some very niche applications aboard my boats.  

In fact, I’ve got some great stories about seawater systems, and have even pondered writing a book about “Adventures in Raw Water Cooling Network Maintenance” …but I doubt it would sell, because it would be a mere microcosm of something that is universally understood by every boater: 

It sucks!  (…and who wants to read about that??)

We tormented boat owners know that the “cost of ownership” transcends the fuel, ice and cold beverages that the uninitiated think is just another fantastic day aboard the boat… 

One of those “costs” is the investment of labor to protect critical systems aboard our boats. Ironically, the most common and recommended maintenance procedure for ANY boat is often the one that causes us the most aggravation… the loathsome Freshwater Flush. I’ve never met one single individual who said they enjoy it (although I’m leaving some room that one day I might.) 

Using seawater can WILL wreak havoc on marine systems over time, whether you operate your boat on inland fresh water, or on coastal saltwater. Mineral scale, corrosion and biofouling build up within internal components like heat exchangers, pumps, and manifolds.  As the scale and corrosion accumulate, they restrict the flow of cooling water and prevent the surfaces of the heat exchangers from transferring heat, reducing system efficiency.  If left unchecked, they can WILL cause serious damage to critical systems over time, resulting in costly repairs.

The simple act of properly flushing a system or an engine with fresh water immediately after every seawater exposure is the most effective prevention method to remediate the negative effects… BUT, the consistent application of the routine freshwater flush is often beyond practical, thus, it has become one of the banes of boat ownership. We all inherently know that we are supposed to freshwater flush our vessel’s systems, but… <insert your own excuse>.   

Which finally brings us to the real reason you even started to read this eccentric journal…  learning the marvels of system maintenance, the exhilaration of wrestling with a recalcitrant garden hose, and the encyclopedia of flushing knowledge (Flush-O-Pedia)!

It is our intent to equip you with perspective and insights into raw water system maintenance and the science behind the Freshwater Flush.  We will cover the historical and current challenges of the traditional engine flushing, and attempt answer the age-old question: “What is a proper freshwater flush?”  We will also explore chemistry, metallurgy, electrolysis, the effects of seawater inside our boat’s systems, the advent of flushing kits, application tips and tricks, and (of course) we will introduce you to the PHIBER solution – a truly innovative and revolutionary approach to streamlining this essential process (and restoring our sanity).

The Traditional Approach to Flushing: Manual Labor & Potential Risks

In the modern sense, “freshwater flushing” means connecting a garden hose between a dock’s freshwater spigot and a local vessel’s raw water system (such as those on outboard and inboard engines).  

Most modern marine outboard engines are pre-equipped by their manufacturer with a dedicated flushing connection that streamlines the process. Any real professional knows that the lime-green, sun-bleached garden hose is the “tool of choice” for freshwater flushing of the engine’s raw water circuit. 

OEM Equipment Manufacturers (outboard engines, stabilizations systems, etc.) generally recommend the following flushing process in their owner’s manuals:

  1. With engine off and vertical, connect garden hose to the flushing port on the engine.
  2. Turn on water and allow fresh water to flow through the engine for 15 minutes (125-150 gallons of water)
  3. Repeat for each engine (multiply both the flush duration and the gallons of water by the number of engines)
  4. Remove garden hose and place engine into stowed position 

Compliance with the OEM Overlord’s flushing demands can be cumbersome and time-consuming, especially for boats with multiple engines.  Given the average time for setup, flushing, and breakdown of a flushing session, it may be more like 20 minutes… per engine.  It adds up fast, and if you actually follow these recommendations, you really do love your boat!! 

For inboard engines and systems, connecting the lime-green, sun-bleached garden hose to a raw water network can be significantly more challenging.  It often requires a custom connection solution, such as a modified sea-strainer (inboard system) or other apparatus where fresh water can be introduced.  For larger yachts with inboard systems, there is the added burden of being flushed while “in the water”, which can significantly complicate the labor process. Seacocks and valves must be tended to, and to prevent flushing damage to the inboard system, the flush must usually occur with the system’s raw water network ACTIVE (i.e. with the engine running).

Aftermarket Flushing Kits

Strict adherence to OEM guidelines for freshwater flushing maintenance of outboard engines can take longer than it does to clean the boat after a day at sea…  As such, several aftermarket Marine Engine Freshwater Flush kits have entered the marketspace in the last several years. 

For the dedicated individual who follows the OEM flushing dictates, these flushing kits and specialty connectors offer some relief as they streamline the freshwater flushing connection, or will often handle the sequencing between multiple engines… but they do not eliminate the human intervention necessary to perform a proper flush.  The owner/operator must still hunt a freshwater source and corresponding hose, make the connections, initiate the flush, wait for the flushing to complete, and then break down the system.

Aftermarket flushing kits for inboard engines and systems are nearly nonexistent, and it is often incumbent on the “creative mariner” to develop a solution that fits a particular raw water system.  In some cases, outboard flushing kits have been adapted to flush inboard systems, but given the complexities involved with flushing inboard engines, there is extreme risk in their use.  For examples:

  1. Most “outboard” flushing kits introduce flushing water directly into the cooling jacket of the engine’s powerhead when the engine is OFF. If they are used as designed on inboard diesel engines with wet exhaust, their use will expose the exhaust manifold to flushing water, which can back up into the cylinders, hydro-locking the engine and causing major damage.  
  2. Zero “outboard” flushing kits are designed with intelligent controls that allow precision-flushing of a specific application, which is absolutely necessary to eliminate risk when flushing inboard engines.  

Until 2024, the challenge of flushing inboard systems has prevented the adoption of commercially available flushing kits from gaining traction due to the complicated implementation and risk of use.

Introducing the PHIBER System: Freshwater Flushing at Your Fingertips… For Realsies

The PHIBER System is a revolutionary freshwater flushing system that transforms any raw water system, bringing it into the 21st century standards for both function and design.  It was engineered and tested over three years, and designed specifically for marine systems that use raw water for their function, especially both INBOARD and OUTBOARD propulsion engines.  It uses an intelligent control system and simple physics to execute complete flushing, at the touch of a button.

The System’s industry-first design revolutionizes the “industry-standard” flush procedure through the employment of a patented intelligent Control & Manifold, which is custom tailored to each vessel’s exact needs.  Once installed, it is configured to provide precision flushing, including the exact duration and water flow necessary for a proper flush for any application that can benefit from routine flushing. It eliminates waste and maximizes efficiencies, while protecting a vessel’s native freshwater system and critical systems that depend on raw water networks. 

PHIBER represents the fusion of elegant design and superior function, and sets the standard for the future of raw water system design. It offers the most return for the investment than any other flushing kit available, and it delivers results where all other kits fail to deliver… freshwater flushing, at the touch of a button, eliminating both the human intervention and the risks. 

The investment of a PHIBER system provides Peace of Mind, for All Your Voyages Ahead.  

So, in summary, Freshwater Flushing is certainly NOT a very “sexy” subject, but if you own a boat… or more correctly (per Jeff’s post last week), if YOUR BOAT OWNS YOU, contact us today to learn more about how PHIBER can revolutionize your boat’s maintenance routine.

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