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**Minggat** · 27-05-2012, 15:24

After 2 years in dry storage I found a while delicate crystal like substance floating in the coolant system of my Perkins 4-108 before splashing the boat. Above about 1400 RPM the engine ran hot on the 3 day passage from Puerto Escondito to La Paz. Changed the seawater impeller. After getting to La Paz I went thru the heat exchanger. It needed it badly. That was 5 months ago.

But just now checking the reservoir I see the white crystal again.

Hint. Have not been here/ the boat has not gone anywhere. The engine has only been run at the time of the heat exchanger re-install. I did notice that the coolant level is low as well. It was topped off when I did the work.

I'm thinking the white floaty stuff is a result of sitting. Anybody have an idea what I'm talking about? I know that I don't

capn_billl · 27-05-2012, 16:30

salt precipitating out from the coolant?

**Cheechako** · 27-05-2012, 16:31

In the anti freeze mix? AF makes some wierd crystals sometimes....

**Snore** · 27-05-2012, 16:44

Quote:

Originally Posted by capn_billl

salt precipitating out from the coolant?

Interesting theory, could do low tech test.... Are crystals water soluble?

**Minggat** · 28-05-2012, 08:17

Yes. It's in the anti freeze mix. And weird does describe it pretty well. actually that answer kinda makes me feel better.

I was trying to preserve the stuff and it simply breaks up very easily. So can't really say if it's water soluble. But it was very white. Not so translucent.

Salt crystals are cubes and they sink.

**Cheechako** · 28-05-2012, 08:23

I would break them up and flush and replenish the AF mix with good quality AF. 50/50 fresh water.

capn_billl · 28-05-2012, 08:33

My next guess is calcium if the heat exchanger was filled with hard water, antifreeze mix, and some of the water boiled out it would leave a saturated solution, and the calcium would precipitate. I would second the flush and refill.

**hellosailor** · 28-05-2012, 10:14

Mingaat-
A lot of folks think "antileak" antifreeze must somehow be better. Which is how it was sold for years. But most of the antileak stuff does that by adding sodium silicate, aka "waterglass", which forms a glassy crystaline coating on all the interior parts. And prevents full heat transfer, and clogs small passages, but that's neither here nor there.
It COULD be that someone used that stuff once upon a time, and some of the waterglass is breaking free and coming up as crud. There must be some simple ways to test the crud, see if/how it burns, smells, tastes, what dissolves it. If you really want to chase it down, give a sample and a case of beer to any college chemistry student and ask them to get it in the lab. <G>

Or as suggested, do a thorough flush, try to clean it all out, start fresh and see if that's all it needs. FWIW only distilled water and a/f should be put in the cooling system. Sometimes there are enough chemicals in tap water so that it can create problems in a cooling system, and (at least here in the lower 48) distilled should still be something like $2/gallon in the supermarket. Or de-ionized, used in steam irons for the same purpose, no chemical buildups.

**Cheechako** · 28-05-2012, 10:21

Quote:

Originally Posted by hellosailor

Mingaat-
A lot of folks think "antileak" antifreeze must somehow be better. Which is how it was sold for years. But most of the antileak stuff does that by adding sodium silicate, aka "waterglass", which forms a glassy crystaline coating on all the interior parts. And prevents full heat transfer, and clogs small passages, but that's neither here nor there.
It COULD be that someone used that stuff once upon a time, and some of the waterglass is breaking free and coming up as crud. There must be some simple ways to test the crud, see if/how it burns, smells, tastes, what dissolves it. If you really want to chase it down, give a sample and a case of beer to any college chemistry student and ask them to get it in the lab. <G>

Or as suggested, do a thorough flush, try to clean it all out, start fresh and see if that's all it needs. FWIW only distilled water and a/f should be put in the cooling system. Sometimes there are enough chemicals in tap water so that it can create problems in a cooling system, and (at least here in the lower 48) distilled should still be something like $2/gallon in the supermarket. Or de-ionized, used in steam irons for the same purpose, no chemical buildups.

yes, yes, yes... I didnt mention it because I didnt think they still sold it! I've seen chunks of crystals in car radiators from it.