Distilled water in 50/50 coolant mix?

[Bill Root]

Is it necessary to use distilled water in the closed coolant system on Detroits? My mechanic says not really, but others seem to believe that tap water has minerals that could damage the engine. I used tap water in the 50/50 mix in the CATs on TUCANDU, did a coolant check with every oil change and never had a problem. That doesn't necessarily make it right, though. What do the experts advise?

 

[GJH]

In the 8v92 manual, they say "distilled or de-ionized water which eliminates the adverse effects of minerals in tap water is preferred". They then have a chart that shows the maximum acceptable mineral content if tap water is used: Chlorides 40ppm, Sulfates 100ppm, total dissolved solids 340ppm,
Total Hardness-Magnesium and Calcium, 170ppm.

So why not just used distilled, at 85 cents a gallon?

 

[SKYCHENEY]

I would think that any ions created from mineral content could lead to crevice corrosion in the liners on 92's. They are very susceptible to damage from poor coolant. I would only use distilled water and Powercool and check them at least once per year with the test strips. I have seen more than one 92 with coolant in the oil. You really don't want that.

 

[Walter P]

Thanks Bill for starting this thread on the Tech page. As per our discussion on the hose nozzle thread on the parts for sale section, I have always used distilled water since I didn't want to second guess the folks who build the engines and manufacture the coolant. As Sky stated, it is probably more critical on wet sleeve engines (53 & 92 series) than on "dry sleeve" such as 71 series and others. I don't know much about the engines on your 43 but perhaps it was/is OK to use tap water. Another issue is that tap water varies from supplier to supplier as to mineral content so what may be OK in your area would not be good in mine. As George said, at the low cost of distilled water, why take a chance. I would still like to know if water saved from dehumidifiers would be OK. While it is not distilled, it is condensate from the water content in the air. I know, I know why take the chance but you must remember that I have a reputation to uphold as a very frugal boater. Bobk has been nipping at my heels for the coveted title.

Walt

 

[34Hatt]

Thanks Bill for starting this thread on the Tech page. As per our discussion on the hose nozzle thread on the parts for sale section, I have always used distilled water since I didn't want to second guess the folks who build the engines and manufacture the coolant. As Sky stated, it is probably more critical on wet sleeve engines (53 & 92 series) than on "dry sleeve" such as 71 series and others. I don't know much about the engines on your 43 but perhaps it was/is OK to use tap water. Another issue is that tap water varies from supplier to supplier as to mineral content so what may be OK in your area would not be good in mine. As George said, at the low cost of distilled water, why take a chance. I would still like to know if water saved from dehumidifiers would be OK. While it is not distilled, it is condensate from the water content in the air. I know, I know why take the chance but you must remember that I have a reputation to uphold as a very frugal boater. Bobk has been nipping at my heels for the coveted title.

Walt

I think you answered it all see the BOLD section.

 

[Boatsb]

Walter use the dehumidifier drippings for drinking. Your system may be more tolerant than the 92's.

I am building a still on the boat to make my own water and maybe some "solvents" too.


All kidding aside I buy cases of distilled water for batteries and coolant and the biggest problem I see is getting rid of the empties after I use them. My wife has grabbed a few gallons of the distilled for drinking water and no problems so why not just do it right for the extra $25 every 2 years.

 

[Bill Root]

Walter use the dehumidifier drippings for drinking. Your system may be more tolerant than the 92's.

I am building a still on the boat to make my own water and maybe some "solvents" too.


All kidding aside I buy cases of distilled water for batteries and coolant and the biggest problem I see is getting rid of the empties after I use them. My wife has grabbed a few gallons of the distilled for drinking water and no problems so why not just do it right for the extra $25 every 2 years.

Thanks to everyone for your responses. I just never gave it much thought until Walt's question about dehumdifier drippings got me thinking. I'll be using distilled water exclusively in my 8-92's. It's certainly cheap insurance.

 

[SKYCHENEY]

Walt got me thinking. I've been wondering if the saliva that drips from my dog's mouth all over my parquet floor in the galley might be put to good use in my batteries? We could make it at any time. All we have to do is crinkle some plastic wrap.

 

[Walter P]

Sky, Dog drool makes great polish for your afromosia paneling... Thanks guys for setting me straight about DU condensate. I guess there really is a limit on how frugal (cheap) a person can get.

Walt