I fixed it!  Yippeeeeeee!

After running aground on Monday I had cleaned out both the stb and port sea strainers.  I still didn’t have good water flow in the exhaust of the stb engine.  I decided to check the impeller, which was good, but unfortunately while pulling it out I damaged it.  I thought I’d have a spare on board, but I did not.  Whoopsi.

For those of you who don’t like to read – go to the bottom and watch the video summary.

I ordered one and had it overnighted to the west marine that I can reach on my bicycle.  $130.00 later I had my new impeller.

I installed it, and still did not have good water flow.  🙁  After talking to a friend of mine who’s an experienced captain he said it sounded like I wasn’t getting a good prime to the water pump.  I looked at the lid to the heat exchanger and decided to seal it super-good using some permatex.  Still no good water flow.

I’m learning that a closed cooling system on a boat has a heat exchanger instead of a radiator like a car.  It uses raw sea water to cool the antifreeze in the engine.  This sea water passes through a tube bundle in the day tank (also known as a heat exchanger).  I must have mucked those tubes up pretty badly.

I pulled the plugs to the front of the day tank (turns out they are supposed to have zincs on them, mine were completely gone).  Another good lesson learned (http://realitycheck.me/checking-and-changing-heat-exchanger-zinc.htm)

The corrosion inside there looks pretty bad so I pulled the side of the day tank off (the one closest to the center of the boat is easy to reach.  Sure enough, it looked like they were completely clogged.  🙁

So, now I had to pull the other side off, I made a board to lie on and crammed myself in front of the starboard engine to finally reach the other side.  It was a total pain in the ass to get that thing off.  Anyway, after doing that I could shine a light on one side and see if I had clear tubes.  Only about 10% of the tubes could I see light through.

I used a coat hanger to clear the tubes, but it left a ton of that gunk in there.  I decided the best way to clear those was to use water pressure.  Unfortunately the weather was cold that day (38 degrees) and so was the water.  I ended up clearing almost all the tubes, and as the water came out it was hitting me in the chest.  I looked like a drowned rat after that was done.  The shirt I had on will never be the same.

That silt material from the bottom of this channel is really gross.  I think it’s like radiator stop-leak combined with crude oil.  Ick.

Finally, after putting the whole thing back together I was completely dismayed to find that I STILL did not have water flow.  Damn.

This morning I decided to try one more time to find the problem.  It must be a priming issue, because everything else has been eliminated.  I decided to try and find an air leak by disconnecting a hose on the upstream side of the water pump and blowing into is (yeah – I put it to my mouth).  I could hear the leak going but couldn’t see it.  I tried spraying windex all over the place (every pipe and fitting) and looking for bubbles, no help.

I took the hose off my shop vac and used it as an extension (and it tasted even worse) I now could hear the air coming out of the top of the sea strainer (the VERY FIRST thing I looked at / fixed).  I had put permatex on that thing but I still had a leak somewhere.  A quick google search revealed that they’re supposed to have a seal (older ones had a cork gasket).

So I made a gasket out of cork and tried it again.  This time it worked, so I decided to prime the system using the shop vac.  It wouldn’t prime!  UGH!  If my shop vac couldn’t prime it that little impeller sure couldn’t either.  I pulled the lid to the strainer off one more time and used vaseline on both sides of the cork gasket this time.  Now – finally – I could get it to prime with my shop vac!  YIPPEE.

I put the whole thing back together and finally have water flow.  Thank God!
Here’s the tube bundle – all clogged up.

Here’s those infamous missing (used up) zincs.
This is what my shirt (and my whole body) looked like after flushing the tube bundle

And here’s the final piece to the puzzle – the cork I made for that sea strainer preventing the water pump from priming.


Finally – here’s that vid I promised.