Leave In or Drain The Pink Stuff?

[tommyt]

I would not worry too much about condensation in the lines. Condensation caused by shrink wrap is why I hate shrink wrap. Replaced floorboards in some boats caused by poor shrink wrap jobs, and seen too many instances of mold on shrink wrapped boats. It does create a greenhouse, and venting only sometimes works.

As for draining and red pop, I use the same system that our charter fleet does, because it has worked for them for years without frozen lines.

Drain the tanks into the bilge or run the pump if you want. Get the water out of the tanks.I do not put red pop in the tanks as they drain fine with the line to the pump disconnected. I then disconnect the line to the pump, put a new hose on it, drop the end of this short hose into the red pop bottle, and pump away. Once it is primed it goes into the system ( hot water tank bypassed) and I open one faucet at a time until red pop flows. Close that faucet and open it's counterpart. Work through all faucets in this manner. Don't forget the swim shower or anchor wash down if you have them. After one and a half bottles of red pop the system is full of red pop. Turn off the pump and leave it. I reconnect the tank line in the spring and leave the lines charged. Obviously, it will not still be charged in the spring, my system is pretty good at holding pressure, but not that good.

As to seacocks freezing......they won't because they are ALL open for the duration. Splash the third week of April, water temp then about 46 degrees. DO NOT FALL IN!

[CapnHand]

Originally Posted by k1vsk

Given this stuff expands as temp decreases, it occurs to me a full system can be more problemmatic for that reason alone

That's incorrect .

[vabuckeye]

http://www.boatus.com/seaworthy/winter/default.asp

This doesn't answer all of the question, but is worth the read.

[tommyt]

OH, and the second half of the second bottle is used for the head. Take off the inlet hose, put the short hose on it, prime and pump through the head. Water out, red pop in, head pump is safe.

[TrueBlue]

What I do is drain all the water from the 140 gal tank (gravity drains on all sinks) and all fresh and seawater pressurized supply lines. In my case, three sinks with taps, two saltwater deck bibbs and two interior saltwater faucets. The 2 Par pumps are the belt-driven diaphram type and pump themselves dry.

I then disconnect the water lines from the Par pump outlets, open every faucet on the boat and blow all water residue out with an electric compressor. I've also used a nozzle valve attached to a scuba tank, which works equally well.

The water heater is a propane, on-demand type, so no tank. The unit's manifold is drained and drain plug removed prior to blowing out the lines.

All my prior boats had impeller pumps and electric/engine heated hot water tanks. The pink stuff was pumped through after bypassing the drained water heater - left in through-out the winter and drained in the Spring. I really hated using that stuff.

This will be the 4th winterization on this boat, using the compressor method and never had any problems. No chemicals are needed, other than shocking the system with a bleach solution during recommissioning.

[k1vsk]

Originally Posted by CapnHand

That's incorrect .

The above link describes the thermal expansion of glycol solutions as follows:

"Coefficient of Thermal Expansion
Since most applications of brine solutions involve small to moderate temperature variations, it is necessary to provide some expansion volume to absorb the expansion...due to temperature variations..." and goes on the provide the thermodynamic equation to calculate expansion coefficients.

As you can see from the graphs or an understanding of the equations, glycol DOES expand with decrease in temperature.

The issue becomes moot unless you leave the system charged; simply filling it doesn't do that. As long as you relieve the pressure, expansion is possible but I don't know why it would be worth the chance.

[CapnHand]

Originally Posted by k1vsk

Given this stuff expands as temp decreases, it occurs to me a full system can be more problemmatic for that reason alone

k1vsk, you started out wrong and now you're going deeper

a) "this stuff" is propylene glycol, aka propane-1, 2,-diol, aka methyl ethylene glycol (C3H8O2)
b)The density of propylene glycol (in Fig 7 of the reference I provided), increases as temperature decreases meaning that the volume decreases as temperature decreases. It does not expand as temperature decreases as you stated above.
c)The coefficient of thermal expansion (cet) is positive over the entire temperature range (Fig 12).
dV/Vo = cet * dT/To
As the temperature decreases, the volume of propylene glycol decreases. It does not expand as temperature decreases as you stated above.

There are no problems caused by propylene glycol expanding as temperature decreases, since it doesn't do that.

If you are an engineer, or studying to be one, I am sure there are many things that you know. My advice is that you should stick to writing about those. Otherwise, people may follow poor advice.

[k1vsk]

Originally Posted by CapnHand

k1vsk, you started out wrong and now you're going deeper

There are no problems caused by propylene glycol expanding as temperature decreases, since it doesn't do that.

If you are an engineer, or studying to be one, I am sure there are many things that you know. My advice is that you should stick to writing about those. Otherwise, people may follow poor advice.

Sarcasm isn't needed or appreciated. I won't argue the point as I'm sure practically no one else cares, however, I don't plan to argue credentials or debate the reference you attached which you might read again.

[CapnHand]

Originally Posted by k1vsk

Sarcasm isn't needed or appreciated. I won't argue the point as I'm sure practically no one else cares, however, I don't plan to argue credentials or debate the reference you attached which you might read again.

There was no humour in my post. I wasn't trying to be sarcastic, sorry you took it that way.

That's disappointing. I'm a salesman, in Canada. I leave the antifreeze in all my fresh water lines, cooling water lines, flush it through the head pour some through the sinks and into the bilge. I've read the reference mat'l that was quoted again, as you suggested, but I still think I'm interpreting the information correctly. If I've made mistakes there, why won't you point them out, for my benefit and others who might read this? I don't mind admitting if I've made a mistake. I wouldn't want to be doing something wrong when winterizing my boat or giving information that might cause others to.

[DrB]

Okay, I prefrace my response with the fact that I have a BS and PhD in Chemistry and Material Eng.

There seems to be confusion on the expansion versus temp of glycol as the temperature changes. The coef. of thermal expansion measures the change in dimension/dimension of a material. It is a dimensionless number. for example a CvT = change in volume/volume-K or change in volme/volume per degree kelvin.

For a given composition (50:50, 70:30, 30:70, etc.) of Glycol/Water, the expansion cofficient goes down with temperature. However, at the phase change (freezing into a solid) the solid has a higher volume than the liquid, so it expands. Obviously not what we want.

If you change the amount of glycol in the mix, the thermal exp. coef. changes; more glycol, a higher expansion coeff., less glycol, lower. Also, if the temperature changes, the expans. coeff. changes. Cooler temps mean lower expansion coeff.

For your temp climate, you need to choose the lowest temp that you think will occur (and then go 20 deg colder) and mix your water/glycol mixture for it.

The statement about allowing some room for the glycol/water solution to expand, in the cited reference by k1vsk, is due to the fact that the day you fill the tank may be 40 deg F and the next day 80 deg F. If you top it off at 40, there is no room for the expanded material to go at 80. If you fill at say 80 and the temp drops to say 30, the liquid will contract and you may be lower than the amount you need to effectively work until the liquid warms up. This is why they have a overflow reservior with your engine that has a high/low fill line. The reservior allows for the expansion volume while providing enough material for proper levels if the engine is cold until it warms up.

DrB

EDIT - Thanks for all of the responses to my OP. I'll leave the Pink in.