Winterising: using windscreen washing fluid instead of glycol?

venntim

venntim

Active Member
Joined
13 May 2009
Messages
44
Location
Helsinki, Finland
Visit site
Been wondering for a while if you could substitute glycol with windscreen wash as the antifreeze in the sea water system. Why? Because I believe that it's less harmful to the environment compared to glycol (it's hard to catch all the stuff from the exhaust). Is there any unwanted size effects such as lack of rust inhibitors and such?
 
venntim said:
Been wondering for a while if you could substitute glycol with windscreen wash as the antifreeze in the sea water system. Why? Because I believe that it's less harmful to the environment compared to glycol (it's hard to catch all the stuff from the exhaust). Is there any unwanted size effects such as lack of rust inhibitors and such?
Click to expand...

I'm guessing that it's got detergent in it. I can't see that being good for shaft seals etc.
 
Why not just dry the seawater system if you are concerned?
Disconnect a few hoses and attack with wet vac.
You'd have to know the engine well enough to be sure not enough water was left in it to do damage by freezing....
 
sailorman said:
surely better to have 50/50 af with its inhibitor`s to stop corrosion
Click to expand...

Not sure.
The inhibitors would be best for a closed system that's completely full, but bits of the raw water system that are wet but not immersed might be better off dry?

I like to reduce the chances of any fluid leaking into the bilge and making the interior damp.
Also, it's good to strip and check things like impeller, mixing elbow etc.

I note the OP is in Finland, freezing will be a more serious problem than in Portsmouth!
 
My final task as I approach the hoist (now crane) is to shut the sea cock and pour a gallon of antifreeze through the running engine via the sea water filter basket. My intent is to clear away the sea water in the hope of preventing crystalisation of the salt. Not sure if it does any good but I've done it for years and it makes me feel better for trying. I'm afraid that the environmental impact comes second at such times.

I don't imagine that there is a great deal of fluid remaining in the sea water system once the boat is out of the water.

Windscreen wash contains alcohol so, presumably, just as harmful to the fish. Why not just flush with fresh water?
 
venntim said:
Been wondering for a while if you could substitute glycol with windscreen wash as the antifreeze in the sea water system. Why? Because I believe that it's less harmful to the environment compared to glycol (it's hard to catch all the stuff from the exhaust).
Click to expand...

It's a while since I looked it up, but as I recall the ethylene glycol in an average engine is below any harmful level by the time it has spread out a metre from the exhaust (i.e. in a one meter radius hemisphere) and it breaks down anyway within a few days. Don't drink it, but apart from that it's not a big issue.

Tranona said:
The water trap may well have a drain plug for that. All the current Vetus ones do.
Click to expand...

Unfortunately the drain plug on my Vetus water trap (LP50) is at the "exhaust" end rather than the "engine" end, which means it's completely inaccessible unless I take the whole thing out ... in which case the drain plug is unnecessary. Half a gallon of blue antifreeze therefore went through my 1GM10 yesterday ... diluted 50:50 with water, because neat antifreeze is not actually very good at preventing freezing:

freezept.gif
 
venntim said:
Been wondering for a while if you could substitute glycol with windscreen wash as the antifreeze in the sea water system. Why? Because I believe that it's less harmful to the environment compared to glycol (it's hard to catch all the stuff from the exhaust). Is there any unwanted size effects such as lack of rust inhibitors and such?
Click to expand...

I use propylene glycol (50/50 mix) to winterize the sea water side of the cooling system, as I believe it is less harmful to the environment than ethylene glycol. Still contains the rust inhibitors etc, though.
It should be possible to get hold of plain propylene glycol, this is part of many consumer products and not regarded as toxic at all.
For the fresh water side of the system I use ordinary ethylene glycol (50/50 mix) that is changed every five years or so. Treated as hazardous waste.
Probably more complicated if your engine is sea water cooled, i.e. no heat exchanger.

http://en.wikipedia.org/wiki/Propylene_glycol
 
nigelmercier said:
Not a good idea, antifreeze contains corrosion inhibitors, windscreen wash does not. They even sell antifreeze in the Canary Islands for this reason.
Click to expand...

+1

Antifreeze is a bit of a misnomer really, though it does have such properties. I prefer to follow Volvo's line and refer to it as "coolant".

Pete
 
Depends on the washer antifreeze.
Cheap ones use methanol - butyl alcohol the the industry recommendation.
No inhibitor, needs far higher concentrations to give as good protection as ethylene glycol.
The pink premix is, in fact, propylene glycol - far less toxic and environmentally damaging than ethylene glycol and equally effective.
Suggest you use that - more effective, cheaper, safer to you, the environment and your boat than any washer additive.
 
Last edited:
I put screenwasher fluid down lavatories [5 litres each] & flush through, then flush through previously emptied black tank to get whole system protected: wrong?


John G
 
Jegs said:
I put screenwasher fluid down lavatories [5 litres each] & flush through, then flush through previously emptied black tank to get whole system protected: wrong?


John G
Click to expand...

Not wrong - just ineffective. But then my boat isn't in an area with constant sub-zero temperatures over the winter.
Would not polypropylene glycol @ 20% of the volume be more cost effective (and slightly better protection)?
 
prv said:
+1

Antifreeze is a bit of a misnomer really, though it does have such properties. I prefer to follow Volvo's line and refer to it as "coolant".

Pete
Click to expand...

The name antifreeze comes from the days when it was just that. The inhibitors were not as good as the ones used today so we used to drain the antifreeze out at the end of the winter and refill with fresh water ..... refilling with fresh antifreeze might have been more sensible though.
 
You must log in or register to reply here.

Share this page

Top