Boats and freezing temps - advice (1 Viewer)

[LandCruiserPhil]

The next few days it will below freezing where I live in AZ.

Do I need to worry about my boat? I have a Chaparral with A V8 and Alpha outdrive. I do have an 13 gal fresh water plastic tank for the sink with water in the tank but its vented. Should I be concerned?

 

[snobdds]

Everyone's interputation of "freezing" is different...are we talking 30* cold or -10* cold?

I have been known to throw a bottle of Iso/alachol in my old motorhome's water tank on hunting trips to keep it from freezing on the way home. It works until I can dump out the standing water.

The motor should be fine if it is not running straight water.

 

[LandCruiserPhil]

Talking 30°

The motor pumps water from the lake through the engine, open system.

 

[snobdds]

That's a tough call. I don't that is block cracking cold, but it's cold enough for cause of concern.

I guess if it was me, I would get all the water I can out of all the tanks. Then put a little bit of RV antifreeze in the tank. Flush it in the spring and your good to go...
As far as the engine goes, I don't know enough about how that system works to provide an answer. I would think once it's out of the water a lot of water back flows out, however I am sure some remains in the block...but how much I don't know. If it was a lot, a lot of boat blocks would be rust buckets after a few years. So I guess I would just cover it with a concrete tarp to hold any radiant heat in.

 

[Michael Hanson]

Hi, Based on my experience breaking my block, I was sick at the time, yes. drain all water. Mike

 

[LandCruiserPhil]

Im thinking little to zero water is still in the block.

Ill put a little anti freeze in the fresh water tank to be sure. Toyota red so I dont forget when summer rolls around.

 

[Michael Hanson]

Sounds good, can you hit it with a drop light. Mike

 

[robbs6940]

Sorry to be catching this so late. Didn't even know we had a boat section. I wrenched on boats for 8 years before current job. All the water gravity drains out of the sterndrive (big outside part) . Engine holds a 2 to 3 gallons. When I "winterize" a boat like that, I have a special rig to run RV antifreeze in through the water pickup, and it takes about 2 gallons for the discharge to get "pink" like the antifreeze.
30 degrees over night...sleep well and don't worry. High of 25 degrees, concerned. High of 25 for 3 days, goner. To drain water you should have a minimum of 4 blue plugs, depending on year model (blue because it is a mercruiser, OMC and volvo use brass). Considerably older Mercruisers may have brass plugs or petcocks. One on bottom side of each exhaust manifold, and one on each side of block. If newer, you may also have one (or more) on the thermostat housing and/or one on the underside of the "y" where upper and lower water hose merge to water pump hose. pull those and let it sit. All the water will drain. For low of 30 degrees, throw a $5 clamp light in there and have a good night. Hope this helps for future reference.
Tip, trim the sterndrive down. Do not leave it up. Water can accumulate in the nose cone and crack the foot. Rare but it happens.

 

[dad4x4]

Robb, great write up. I wish it was posted a year earlier. A friend of mine moved up to GA from the warm weather in florida and had never winterized anything. Last years winter in the south was very cold with numerous days in a row in the teens. He put the boat up for sale and during the first test drive he found out that his brand new volvo Penta 350 had a cracked block. Him and I installed the new engine last summer after the oil pump quit. Anyway, he found out the hard way.