Wintering Mufflers and Seacock for in water storage

[kc-excursion]

Hi,

Longtime boater with some nagging questions. We have a new boat this year. A 1989 13m express with Detroit Diesels 671's, winterizing is complete.

Background
The diesels are closed circuit cooling
In this part of the Midwest, the boats are stored in the water with bubblers, We have winterized many boats for in water winter storage through out the years.
We will see overnight lows in the -15 to -5 and single digit day times highs for part of the winter

Concerns
1) The mufflers were drained; however, the bottom edge of the port exhaust opening is approximately 1/2" below waterline and fresh water does feedback into the muffler. The port muffler will drain forever. The starboard exhaust port is 1/4" above the water line. Approximately 12 gallons of pink was pumped through the raw water system on each each side with engine running. The starboard muffler is full of the pink. The port muffler has some pink, but how much is unknown.

2) The engine seacocks are substantial with large strainers. The small drains on the seacocks are for the ball portion only and do not drain the remaining water. Thus there is about 3"x10" water column (before the strainers) holding fresh water. The strainers were drained and back filled with pink antifreeze. While antifreeze is slightly heavier than water, it may not mix or displace the fresh water. Unfortunately, we didn't have a good way of pumping the water out of the strainers when we winterized, considering several options.

Questions
1) Experiences with the exhaust design at water level or slightly below
2) Mufflers freezing
3) Winterizing the seacock

What's been winterized

• Fresh Water System - pumped pink throughout
  Fresh Water Tank - pumped dry and added pink
  Toilet system - pumped pink throughout
  Holding Tank - pumped as low as possible added pink
  Raw Water wash down - pumped pink
  Windshield Fluid - directly supplied from fresh water
  Generator - antifreeze temp verified, heat exchanger drained and filled with pink
  Diesel Engines - antifreeze temp verified, raw water cooling pumped 12 gallons through fully heated engines (used a dump bucket connected directly to water strainer)
  All sea strainers drained

[Diverted Income]

When we bought our F-32, it too sat in the water over the winter. Froze in like the rest of the boats in that area. Closed cooled as well. Winterized much as yours. Exhaust tips sat at or just below waterline too. Strainers were full of antifreeze but bottom section of seacocks sat with water. Ambient temp of water below the boat saves the seacocks. I imagine there was some ice in the mufflers though, had to be. That was all new to me, letting boats ice in. No bubblers. This was in a harbor on the Mississippi near St. Louis if that helps.

[jhalb]

I run blue coolant (-100) through my 350s. I figure if the river water gets in my side exaust it will mix and still be ok. I run pink in the rest of my systems.

[Diverted Income]

I run blue coolant (-100) through my 350s. I figure if the river water gets in my side exaust it will mix and still be ok. I run pink in the rest of my systems.

There you go. Our F-32 was a only a couple harbors downstream from jhalb!