Thursday, November 20, 2014

Life On The Hard - Rudder Bolts and Black Gold

Front two bolts are corroded
November 7th
As Tom started working on the prop and rudder he did find a couple of surprises.  The first was a dead crab.  It had crawled into the space between the rudder and the keel.  We think it climbed in when it was little and then enjoyed the small barnacles in there.  However, after feasting on those, it grew big and couldn't get out.  Additionally and more concerning were that two of the four rudder bolts were very corroded.  These are stainless steel and should not have corroded.  Further investigation suggests stress corrosion.  Thanks John B for your insight on this.  Tom replaced all four with beefy new stainless steel.  Going forward we will keep a very close eye on these for wear.
New bolts
We continue to get questions about the awesome bottom paint that has lasted for 4 1/2 years.  Tom was able to call the Florida boatyard that put it on.  They have great records and showed it is Pettit Trinidad Pro. We promptly ordered the same again.  Bottom paint is very, very, very, very expensive.  It is important to get compatible or same paint to put back each time....hard bottom paint needs to be covered again with hard bottom paint or ablative paint back with ablative.  Mel at Majestic here in Coral Cove was able to procure some Pettit Trinidad Pro ($350 US dollars per gallon).  I know!  Pure gold!
Black Gold

All the stuff that marine creatures don't like
Turns out bottom paint in a very personal thing.  One boat will have a great experience with a particular bottom paint and the next will have a terrible experience with the same paint.  It seems prep is the key to making bottom paint work.  Additionally, conditions the boat is kept in make a huge different - salt vs fresh water, cold weather vs tropical and active use vs sitting for months on end in a slip or mooring.  Ultimately, this Pettit Trinidad Pro (our new gold standard) really seems to rock on our bottom.  Maybe I should be a rep for Pettit Trinidad Pro as I could have sold several gallons this past week given the excellent shape of our hull after 4 1/2 years in the water and number of cruisers that came by to take a look.  Hum?  

1 comment:

  1. Been using TPR for decades. Similar Experience. $250/gal here. We've seen corrosion like this before on nuts in a bilge. It wasn't stress corrosion it was Chinese Stainless mixed in with an order of the real stuff. The builder (and no one else) had anyway to weed it out. The chemical mix was right, the temp control in the alloying process wasn't.