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Old 29-01-2015, 12:03   #1
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Salt vs Fresh water ?

Silly question? Are boats designed specifically for fresh water ( lighter keel ? ) or do the fresh water guys just have to paint their boot-top a bit higher?
I am thinking of buying a used fresh water boat, - would that be any better/worse than a salt water boat in terms of moisture ingress to the core or any other considerations?
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Old 29-01-2015, 12:22   #2
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Re: Salt vs Fresh water ?

Thomas hardware in Grosse Point told me something I did not know about. Fresh water boats use SS314 rigging and salt water boats use SS316. more expensive for sure. Thomas hardware is the sailboat rigging and supplier around here
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Old 29-01-2015, 13:00   #3
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Re: Salt vs Fresh water ?

No, manufacturers don't build differently for fresh or salt water boats. And yes, there will be slight differences in immersion depth due to the difference in density.

But, there certainly is a difference in the effects of salt and fresh water usage on various parts of the boat. Corrosion, of course, is far worse with salt, so a fresh water boat may well be in better condition in many areas than her salt water sister. Then too, many of America's fresh water boats come from areas with severe winters, where the boats are stored ashore for much of the year (poor sods!), and this reduces the annual wear and tear somewhat... again good for the later buyer. The down side of that is the possibility of freezing damage from any trapped water in the boat. Rudders and encapsulated keels are subject to such problems, and there have been many threads here on CF related to the issue.

So, like so many factors in yachting, there are conflicting trends here. As always, a good survey will help in your decision on a specific vessel.

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Old 29-01-2015, 15:34   #4
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Re: Salt vs Fresh water ?

Salt water boat usually carries enough fresh water to make up the difference.
Plus a lot of other stuff since they often go on slightly longer trips..


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Old 30-01-2015, 07:02   #5
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Re: Salt vs Fresh water ?

Except for some small metal boats and some stupid advertising claims, there is no such thing as a "fresh water boat" or "salt water boat" Boats are boats, made to be used in the water. Consider a trip on the AICW from Norfolk, VA to Miami, FL. You will be in salt water, fresh water and brackish water and this will change during your trip.
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Old 30-01-2015, 07:38   #6
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Re: Salt vs Fresh water ?

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Originally Posted by sailr69 View Post
Thomas hardware in Grosse Point told me something I did not know about. Fresh water boats use SS314 rigging and salt water boats use SS316. more expensive for sure. Thomas hardware is the sailboat rigging and supplier around here
Show me a manufacturer that offers salt water rigging vs fresh water rigging. They don't offer differnt rigging. Your hardware guy may sell a cheaper option but it is hardly typical.

Generally fresh water boats are considered better as they will have less corrosion for a similar age.

The one exception is the engine cooling system. Some (but by no means all) fresh water boats will use raw water cooling. That is they pump water directly from outside the boat, thru the engine block. As long as the boat stays in fresh water, this isn't usually a big problem. Boats sold in salt water areas almost never have raw water cooling. But you have to ask about the cooling system as there is no guarantee you won't find a boat that has moved from one area to the other.

Update: One clarification, I am assuming you are comparing two otherwise identical models. There are some manufacturers (houseboats in particular) who will use lower grade materials since they don't expect the boat to see salt water.
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Old 30-01-2015, 07:43   #7
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Re: Salt vs Fresh water ?

Quote:
Originally Posted by holmek View Post
Silly question? Are boats designed specifically for fresh water ( lighter keel ? ) or do the fresh water guys just have to paint their boot-top a bit higher?
I am thinking of buying a used fresh water boat, - would that be any better/worse than a salt water boat in terms of moisture ingress to the core or any other considerations?
No reason not to buy a freshwater boat (one that was lused exclusively in fresh water) and use it in saltwater. Just make sure you take off the freshwater zincs and put saltwater zincs on.

Yes, your boot stripe may ride incrementally higher, but that just means you don't have to clean it as often.
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Old 30-01-2015, 07:44   #8
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Re: Salt vs Fresh water ?

As to the rigging that is the first time I've heard of 314SS being used. Maybe your rigger is using it as a cost effective alternative for boats that are staying in freshwater. The riggers at Torrensen use 316SS, and most of the boats that I've looked at came with 316 or when they'd been re-rigged had been done with 316. I've no idea the different tensile strength of 314 vs 316 either but if close I'd assume it be an acceptable swap out if there was enough of a price difference to warrant it. It would be a bit of a surprise to anyone buying a Great Lakes boat to have it trucked elsewhere though.

The nice part about freshwater is that our rigging usually will show no signs of corrosion or pitting on stainless steel. I did see one very poorly made Lewmar stainless wheel rust after one year in the Great Lakes. That was a bit of a shocker. You have to wonder what the heck they were calling "Stainless". The company did make it right in the end though.

Also thru hulls made of quality bronze should last the general equivalent of 2 sailors lifetimes. There are some old woodie yard queens quietly decaying in the yard still complete with original 1920 bronze thru hulls and rudder gear. All still perfectly serviceable, no dezincification here. Also I polished up my bronze Meriman winches 4 years ago and they are just now turning a slightly dull brown. So what we loose in winter time lay up, we make up for with a lack of polishing.... (that math works out right, either way I'll keep telling myself that!)
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Old 30-01-2015, 10:08   #9
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Re: Salt vs Fresh water ?

I've also heard stories of fresh water boats suffering higher incidences of osmosis due to the differance in size/density of the water molecules.
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Old 30-01-2015, 10:19   #10
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Re: Salt vs Fresh water ?

I trailered my strictly fresh water 28' Pearson Triton (about 9000 lbs fully loaded) to the Florida Keys several years ago. When I put it in the water, I couldn't really tell the difference regarding the boot stripe and where the boat sat in the water.


I doubt boat builders would bother making any design changes for vessels that may ply fresh water. There ain't all that much of it and the added design/construction costs would simply not be worth it.
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Old 30-01-2015, 10:26   #11
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Re: Salt vs Fresh water ?

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Originally Posted by valhalla360 View Post
1. The one exception is the engine cooling system. Some (but by no means all) fresh water boats will use raw water cooling. That is they pump water directly from outside the boat, thru the engine block. As long as the boat stays in fresh water, this isn't usually a big problem. Boats sold in salt water areas almost never have raw water cooling.

2. But you have to ask about the cooling system as there is no guarantee you won't find a boat that has moved from one area to the other.
1. Take that one with a BIG grain of salt. Boat engines, like rigging, come from the boat builder as they were built, not where they were intended to be sailed.

2. Contradicts #1!
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Old 30-01-2015, 10:31   #12
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Re: Salt vs Fresh water ?

316ss is a molybdenum-bearing stainless steel. Used in medical and saltwater environments because of the corrosion resistance and resistance to pitting because of the molybdenum. 314ss does not have molybdenum in it and is often used where a high temperature corrosion resistance is needed. Like up to about 2000+ degrees. It is often used in things like furnaces. (I worked in machining for a medical device company and have some metallurgy knowledge. We used a lot of 316 and 316L)
And contrary to popular belief... stainless steel can rust.
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Old 30-01-2015, 10:39   #13
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Re: Salt vs Fresh water ?

There are a lot of fresh water boats with rigging up and no cover during winters, where there is ice and snow...freezing and thawing all winter. I would stay away from these, or seriously look for damage from freezing and thawing.
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Old 30-01-2015, 10:52   #14
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Re: Salt vs Fresh water ?

Take a look at some of the pictures of older vessels that have spent their lives in salt environments and then at the ones that have spent years in fresh water. The corrosive qualities of the salt water environment far outweigh the damage from possible freeze/thaw from an uncovered boat. Boats are designed to shed water. Remember, if you are up in the higher latitudes, the sun damage is less as well.

I would, however, take a close look at the water/holding tank system and engine for cracking of fittings/castings due to poor winterizing.
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Old 30-01-2015, 11:30   #15
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Re: Salt vs Fresh water ?

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1. Take that one with a BIG grain of salt. Boat engines, like rigging, come from the boat builder as they were built, not where they were intended to be sailed. I'm from Michigan and you do see a lot of raw water cooled engines. I think it's less of an issue with newer boats but having shopped the area, they are much more common.

2. Contradicts #1! What contradiction? Boats get moved from place to place. It may not be smart to move a raw water cooled boat to salt water but that doesn't mean someone doesn't do it.
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