Anti-freeze Question . . . Change of Color ???

tpenfield

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OK, I know that the color of RV/Marine antifreeze is insignificant and more arbitrary.

However, I've had a fairly strange occurrence in my winterizing last year and now this year. It seems that on the hot water side of my boat's plumbing system the AF goes in pink (or red for the -100˚F) and comes out of the hot water faucet almost clear. The cold side comes out pink (or red). Initially, I was thinking that I needed to run more AF to purge the water heater, and actually . . . I did drain the existing water from both the supply tank and the water heater tank.

After pumping nearly 20 gallons of AF through the hot side and seeing little/no color (i.e. clear liquid) I came to the conclusion that something in the hot water side might be reacting with the dye in the AF and making it clear. Copper maybe? The stuff coming out of the faucet has definitely got the alcohol smell to it.

2 years ago I noticed a similar lack of color when I drained down the heat exchanger of the engines. I thought it was water, but I smelled the alcohol. . . so it lost its color.

So, does certain types of plumbing react with the dye in AF? copper maybe?
 

WIMUSKY

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20 gals? Holy moly. I know it doesnt answer your color question, but in the rv world we drain the tank and open the bypass valve. If you don't have it can you install one for future use?
 

tpenfield

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Thanks guys. I'm not sure if my heater tank has a bypass valve, but that would certainly work. The water heater looks like this.
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Screenshot 2023-10-01 at 5.19.48 AM.png
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Not sure which/where a by-pass valve would be? The drain that I use is the faucet on the lower left. Of course, being a boat, where the tank is located it is nearly impossible to see or reach.

My other boat (Formula 330) had the same type of water heater, but it seemed to be a lot easier to determine when the AF had run through the hot water side. This boat . . . not so much.
 

alldodge

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I would remove both water hoses and connect them together during winterizing with AF. Later I just used air with a Reg set around 40 psi and blow everything out
 

Scott Danforth

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I have run RV antifreeze in a boiler with temps over 250.

I have run RV antifreeze in various RVs and cabine plumbing systems.

Never have had a color change

Did you drain the water from the system first?
 

Grub54891

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Drain everything, bypass kit on the water heater, disconnect the line from the storage tank and hook up your anti freeze. Run till it comes out of each faucet.
Never had an issue or color change. Usually only a couple gallons is all that's needed. Unless you have a larger system.
 

tpenfield

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Yes - I drained water from both the supply tank and the heater tank then added AF to the supply tank and ran it through the plumbing system via the various faucets waiting for the pink color of the AF to appear. Cold side . . . no problem. Hot side - came out clear. But after a while it was fairly obvious that the 'clear' liquid was AF.

The water heater is a nearly impossible reach, but maybe if I loose 30 lbs. over the winter, I can squeeze my fat butt in there for a better look to see if there is any by-pass, or how I might install something.

FWIW - here is the fresh water system layout of the boat. The water heater is hidden behind an electrical panel. I do not see any sort of by-pass configured in the drawing.
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IMG_5221.JPG
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Access to the supply tank and pressure pump area is even worse than the hot water tank. :ROFLMAO:
 

Lou C

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might want to catch a sample and test it with an antifreeze refractometer, that will tell you for sure...
 

tpenfield

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Well, the boat is winterized and just awaiting the winter tarp. I did find a couple of threads on RV forums regarding AF loosing its color . . . no real detail though . . .
 

Grub54891

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I usually install a hose directly to the pump itself. I understand how you can’t get to it. Usually when the tank is just drained there is a few gallons left behind. After winterizing I hook the pump back up and leave all faucets open.
 

JimS123

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You want to rain the tank and bypass it. You do not want to put AF in or thru the hot water heater.
 

tpenfield

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Actually, I just want to figure out this color mystery 😀.
 

KJM

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Actually, I just want to figure out this color mystery 😀.
I think there may be anodes in the tank. Maybe they react with the antifreeze? You could try putting a small anode or galvanized nail in a small jar of AF.
 

Lou C

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this is a great tool to have, measures both PG and EG antifreeze concentrations.
I use it to mix my own PG antifreeze to winterize the boat, cheaper than the West Marine -100.
 

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tpenfield

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I think there may be anodes in the tank. Maybe they react with the antifreeze? You could try putting a small anode or galvanized nail in a small jar of AF.
I tried copper and brass, but no color change. Could be Zinc . . .
 
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dingbat

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2 years ago I noticed a similar lack of color when I drained down the heat exchanger of the engines. I thought it was water, but I smelled the alcohol. . . so it lost its color.

So, does certain types of plumbing react with the dye in AF? copper maybe?
Try chlorine/bleach
 
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