How effective is a freshwater flush after every cruise?

[BHW-Mike]

New to boating so I apologize for that now. I did search the forum for freshwater flush but didn't find an answer. About July of this year I bought a 2005 Sea Ray 185 sport with just under 300 hours and it has a garden hose attachmnet on the swim deck. The PO replaced the risers before this past season and I've read they last 3-5 years in saltwater. Now I'm waiting for him to tell me how long it has been for the manifolds. Being I'm in NJ and our property is on a lagoon my boat will be in the saltwater for the entire season. In terms of usage I'm hoping we can take the boat out for a cruise every week. My question is about trying to extend the life of the manifolds and risers. If I use that freshwater flush after every cruise will it extend the life? I've read the life has to do with the hours of usage but I'm curious does the majority of the corrosion happen while at speed/running or is there a significant amount of corrosion happening at the dock between runs?

 

[Juliery]

New to boating so I apologize for that now. I did search the forum for freshwater flush but didn't find an answer. About July of this year I bought a 2005 Sea Ray 185 sport with just under 300 hours and it has a garden hose attachmnet on the swim deck. The PO replaced the risers before this past season and I've read they last 3-5 years in saltwater. Now I'm waiting for him to tell me how long it has been for the manifolds. Being I'm in NJ and our property is on a lagoon my boat will be in the saltwater for the entire season. In terms of usage I'm hoping we can take the boat out for a cruise every week. My question is about trying to extend the life of the manifolds and risers. If I use that freshwater flush after every cruise will it extend the life? I've read the life has to do with the hours of usage but I'm curious does the majority of the corrosion happen while at speed/running or is there a significant amount of corrosion happening at the dock between runs?

Rusting is the common form of iron corrosion which occurs when the metal atoms react with their environment. Salt water does not make a metal rust, but it is a good electrolyte so it accelerates the rusting which is an electrical process. Electrons move more easily in salt water than they do in fresh water. So yes, flushing will help slow corrosion. However corrosion will continue even in fresh water and the extent of corrosion is related to time, not operation.

 

[BHW-Mike]

Rusting is the common form of iron corrosion which occurs when the metal atoms react with their environment. Salt water does not make a metal rust, but it is a good electrolyte so it accelerates the rusting which is an electrical process. Electrons move more easily in salt water than they do in fresh water. So yes, flushing will help slow corrosion. However corrosion will continue even in fresh water and the extent of corrosion is related to time, not operation.

Thanks for the technical answer. I Googled outside of the forum and found that most folks strongly believe the a freshwater flush slows the process and that most of the corrosion happens while at the dock... Since most of a boats life is spent there. Even though we all would prefer it to be the other way around! Lol

 

[BillK2632]

Yes, flushing after every use with absolutely slow down the corrosion. By flushing you are not leaving salt water sitting in the engine and manifolds. Does some amount of rust/corrosion occur in freshwater - yes, but I will give you a comparison. My boat is 22yrs old and has the original manifolds and they still look new inside, as do other components like the thermostat housing etc. I have owned a number of boats, all in freshwater, I have never replaced a manifold or riser - in fact it is not something that is even discussed in the areas I boat in. But salt water, yes a whole different story, I would be religious about flush after every use.

 

[Pirate Lady]

Your property is a NJ lagoon. Is the boat staying in water, a lift, trailered out in driveway? Makes a difference.
Flushing definitely is good as said above. If stored out of water much better. If left at slip, that arguable.
Personally, flushing after coming back from every boat use would get old real fast. Weigh $1400 every 8 years against doing that pita after every time you use the boat.

 

[Pirate Lady]

PS Mike…
First boat. 185. You wont have this same boat in 3 years. Really. I wouldn’t worry about it.

 

[BHW-Mike]

PS Mike…
First boat. 185. You wont have this same boat in 3 years. Really. I wouldn’t worry about it.

That's funny. The PO and nearly every other boat owner said the same thing!

But if the flushing works I have no problem doing it especially with the hose being right there anyway as the salt needs to get washed off from the boat anyway.... And it will give me a reason to drink a beer or two while it flushes clean.

 

[BHW-Mike]

Part "B" of my question now. I haven't checked where the hose connection on the swim deck actually goes. But now that I know flushing will extend the life of the risers and manifolds and put off spending $1500 just in parts, what is the best method for flushing the risers and manifolds? Remember I have an I/O Alpha 1 that stays in the water.

I've read another boat owner threaded a hose barb in the left and right drain plugs, then joined them with a "t" and then ran that to a hose connection. He would turn the engine off, hook up a hose to it and then flush it with city water for 10 minutes. After the research that I have done with regards to my Alpha 1 drive, doing it that way eliminates the worry of deadheading the impeller in the raw water pump in the out drive. That was a concern I read when using anything like the Perko Flush Pro, which is used while running the engine, and it supposed to send water to the engine and block the flow from the pickup. In my case it's the impeller in the out drive.

Putting on muffs with a hose fitting is not something I want to do with this Alpha 1 while in the water... Just too awkward and kind of a PITA. Looking for something simple. Let me know your thoughts and I will be taking a ride to go check out that hose fitting on my boat and see how it is plumbed.

 

[mrsrobinson]

Agreed with flushing will get really old after a while, and my guess is the seller stopped doing it after a while as well. I love Volvos salt treatment systems (sarcasm). Every Volvo powered boat I looked at the containers are empty, which means the owners got tired of it.

Enjoy the boat, don't stress over it.

 

[sbw1]

This is purely a saltwater issue. If you boat in salt, flushing helps. Fresh water boaters never even think about this question and wear their engines out after 4500 hours+ over 35 years or more with proper maintenance.

 

[Shaps]

When I bought my boat I had new aftercoolers installed and I also added the freshwater flush strainer caps. I do flush my engines when we get back to the slip, religiously. It becomes part of our routine. takes less than 15 mins to do both engines. Well worth it IMHO.