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Wintering in potentially freezing conditions, watermaker?

SY STELLA
 

Hi folks,
We will be wintering ashore this year at Ardrossan, Scotland where there is a possibility of subzero temperatures and I intend to take measures to combat possible damage due to freezing. I’ve never wintered in such conditions, so it’s a new process for me. I’m comfortable with the obvious stuff like empty water tanks, drain lines, anti-freeze in engine/gen raw water coolant lines etc.

One area that is puzzling me a little is the watermaker system. I’m thinking about some kind of non-toxic antifreeze solution?  

What do others with such potentially sub-zero wintering conditions do with their watermakers?

Many thanks
Dean
SY Stella A54-154
Islay

Thomas Peacock
 

Mark from Dessalator in the US recommends the pink anti-freeze (propylene glycol) alone as an alternative to metabisulfite. So, in cold weather you have both bases covered. 
If you did use metabisulfite, you could add glycerol, but I’m not sure about the ratio. 

Tom Peacock
SM 240 Aletes
Chesapeake Bay US


On Aug 7, 2019, at 5:37 AM, SY STELLA <stella@...> wrote:

Hi folks,
We will be wintering ashore this year at Ardrossan, Scotland where there is a possibility of subzero temperatures and I intend to take measures to combat possible damage due to freezing. I’ve never wintered in such conditions, so it’s a new process for me. I’m comfortable with the obvious stuff like empty water tanks, drain lines, anti-freeze in engine/gen raw water coolant lines etc.

One area that is puzzling me a little is the watermaker system. I’m thinking about some kind of non-toxic antifreeze solution?  

What do others with such potentially sub-zero wintering conditions do with their watermakers?

Many thanks
Dean
SY Stella A54-154
Islay

Mark McGovern
 

Dean,

I've winterized my SM for the last two years.  For the watermaker I did as Mark from Balcen (Dessalator USA distributor) suggested and used marine/rv anti-freeze and it seems to have worked fine as my watermaker output and quality in terms of TDS/EC has been just about the same.  Be sure to drain the flowmeter tube!  

--
Mark McGovern
SM #440 Cara
Deale, MD USA

SY STELLA
 

Thanks Mark and Tom,
I’ve found the Starbrite Pink antifreeze online at Force4 chandlery in the UK. Good to -46C.
I think it’s probably the same product that you use, since it’s sold in US gallon containers.
How many gallons would you normally use? I presume you just use the same pink antifreeze for the engine and genset too?

Mark, may I assume that draining the tube is easy once I’ve removed the control panel from the bulkhead?
Any tricks there?

Also, do you use the manual flush lever/inlet to introduce the antifreeze, or do you run it through the seawater inlet?  I guess the latter is easier.

Many thanks once again
Dean
SY Stella
A54-154

Thomas Peacock
 

Pretty sure the Starbrite is good. Main ingredient should be propylene glycol. 
For engine and gen, we would close the engine room through-hull, then run engine while pouring pink stuff through the sea chest until you could see it coming out the exhaust. Same for gen. 
I would not want to guarantee, but the engine room does stay a little warmer as it is lower, and derives “heat” from the cold Scottish water. Some people augment this with a 100 watt incandescent bulb (if you can find one). 
As I recall, to totally antifreeze the engines, watermaker, and fresh water system, you might go through ten gallons. 
Not sure about the water maker tube, we never did it, watermaker was already asleep with metabi and glycerine. Our manual says to use 10 liters chlorine free water, 100 grams metabi, and 2 liters glycerine ( which provides the antifreeze property). I don’t know if the glycerine can pass through the membrane, it is a very small molecule, kind of like water by structure (OH-OH-OH). If so, that would also protect the tube. Pretty sure propylene glycol will not pass through. 

Tom Peacock
SM #240 Aletes
Chesapeake Bay US


On Aug 8, 2019, at 6:49 AM, SY STELLA <stella@...> wrote:

Thanks Mark and Tom,
I’ve found the Starbrite Pink antifreeze online at Force4 chandlery in the UK. Good to -46C.
I think it’s probably the same product that you use, since it’s sold in US gallon containers.
How many gallons would you normally use? I presume you just use the same pink antifreeze for the engine and genset too?

Mark, may I assume that draining the tube is easy once I’ve removed the control panel from the bulkhead?
Any tricks there?

Also, do you use the manual flush lever/inlet to introduce the antifreeze, or do you run it through the seawater inlet?  I guess the latter is easier.

Many thanks once again
Dean
SY Stella
A54-154

SY STELLA
 

Ok great, thanks Tom.

We'll be wintering ashore, so we don't even benefit from the "warmth" of that Scottish water!
I think I will try to find some kind of "safe" low-level heat producer for the engine room. 

Whilst my Dessalater Duo 100 manual is silent on the subject of anti freeze etc,  it does very clearly state that the membranes themselves should not be taken below 0C.
I guess if I drain the tube, and production pipe from the membranes that will also drain any residual fresh water in the membranes.

I like your solution of using Steriliser + Glycerin, if this passes through the membranes as you suspect, then it would give protection to the tube.

Many thanks
Dean
SY Stella A54-154
Loch Stornoway (Sheltering from a gale!)
  

Thomas Peacock
 

Hi Dean, 
I would not want to count on the glycerine passing through the membranes. On further reading, it is nearly identical in size and structure to propylene glycol. However, if you do keep the engine room a little warm, that should protect the membranes as well. As Mark commented earlier, be sure to drain the part of the watermaker system that is not in the engine room. 
Tom Peacock
SM 240 Aletes
Chesapeake Bay


On Aug 9, 2019, at 6:10 AM, SY STELLA <stella@...> wrote:

Ok great, thanks Tom.

We'll be wintering ashore, so we don't even benefit from the "warmth" of that Scottish water!
I think I will try to find some kind of "safe" low-level heat producer for the engine room. 

Whilst my Dessalater Duo 100 manual is silent on the subject of anti freeze etc,  it does very clearly state that the membranes themselves should not be taken below 0C.
I guess if I drain the tube, and production pipe from the membranes that will also drain any residual fresh water in the membranes.

I like your solution of using Steriliser + Glycerin, if this passes through the membranes as you suspect, then it would give protection to the tube.

Many thanks
Dean
SY Stella A54-154
Loch Stornoway (Sheltering from a gale!)
  

Mark McGovern
 

Dean,

I used Starbrite pink antifreeze the last two winters here in the Chesapeake and it has worked well.  I used it for all systems including: air conditioning, heads, anchor wash, watermaker, freshwater system, engine and generator. All told it took ~16 gallons.  It would be less if you have a second person who can tell you when the pink stuff start coming out of the system you are fillning with antifreeze.  I also made sure to drain and bypass my hot water heater before doing the fresh water system.  One of the winters we had a serious cold snap where the temperature did not go above freezing for close to 3 weeks.  The antifreeze turned into a "slush" in the heads and I was concerned about the watermaker membrane.  However, it appears to be no worse for wear as the output and quality in terms of TDS and EC readings are about the same as they were two years ago.

I would highly recommend that no matter how you winterize the watermaker that you drain the product water line/flowmeter.  While you can do it at the back of the watermaker panel, I found that the easiest way is to undo one of the many connections in the product water line right where it exits the membranes. See the section circled in RED in the picture below:



Just loosen one of those connections and drop the tube low and a small amount of water will come out. It takes all of ~2 minutes and could save you a ton of hassle.  I drained it the first year I winterized when I was being super careful and meticulous but I was in a rush last year and I forgot to drain it.  Sure enough, the water froze and the glass tube of the flowmeter shattered:





I was quoted ~US$400 for a replacement flowmeter from the US distributor for Dessalator.  Ouch.  Figuring that this was an "off the shelf" part I got the manufacturer name and part number off the part and contacted them directly.  CT Platon in France is the manufacturer and my flowmeter had "A10HS – CA251001" engraved on it.  Thankfully, CT Platon is still in business and they still make the part.  They quoted me ~132 Euros plus shipping for a replacement meter.  When I send the Platon representative the pictures above to confirm that I was ordering the correct part number, he told me that the fittings looked fine and that they could just sell me a replacement glass tube and o-ring kit for ~77 Euros.  So all in all, not nearly as costly a mistake as it could have been but one that I will NOT be making again.  So learn from my mistake and drain the tube/flowmeter!

Below is some information for the flowmeter that is on my Amel SM Hull #440 with a Dessalator D160 watermaker:

Glass tube flowmeter type NG
Flow range : 10-100 L/min Air ( please advise if different)
Ref : GTF3AHS-E
100mm ceramic engraved scale
¼’’ BSPP brass rear connections
Brass fine control valve
Brass float / Viton O rings

I have also attached some of the documents that the very helpful and friendly rep from CT Platon sent me.
 
--
Mark McGovern
SM #440 Cara
Deale, MD USA

SY STELLA
 

Hi Mark,
Thanks for the pics and detailed info.  I’ve ordered 10 gallons of the pink antifreeze, and a couple of heaters too!   My flowmeter is a little ‘grubby’ looking as shown in the attachment. It doesn’t affect the water quality, but I might talk to CT Platon about getting a replacement if I can’t find a way to disassemble and clean it up.  

Your picture of the outlet pipework also gave me an idea to see if I can find a suitable access to drain a dehumidifier (by gravity) into the watermaker outlet pipework. I’m really just thinking about the dehumidifier as an additional wintering measure.

Cheers
Dean
SY Stella
A54-154


SY STELLA
 

Just found the answer to the dehumidifier drainage question in another thread about wintering. Use the depth transducer hole. Perfect!
I love this forum.

Mark McGovern
 

Dean,

No problem.  You should be able to clean up your flowmeter glass as it all comes apart pretty easily.  On the SM Amel wired it with plenty of slack so I could drop it on the galley counter and work on it.  I do wonder how the glass got dirty, however, as it should only ever be exposed to "clean" product water that came directly from the watermaker.  So that is a bit odd. 

--
Mark McGovern
SM #440 Cara
Deale, MD USA