Facebook

Home

About Us

Services

Links

Underwater Fittings in a Salt Water Environment

  Galvanic Corrosion, often misnamed "electrolysis," is one common form of corrosion that takes place between metals. It occurs when two (or more) dissimilar metals are brought into electrical contact when immersed in seawater (an electrolyte). Because each metal has its own voltage potential, the metal that is most active electrically will deteriorate while protecting the metal that is less active. So when a galvanic couple forms, one of the metals in the couple becomes the anode and corrodes faster than it would all by itself, while the other becomes the cathode and corrodes slower than it would alone.

  In the case of the propeller and shaft relationship, where the propeller is normally bronze (the anode) and shaft is stainless steel (the cathode), we wish to protect the propeller from deterioration. Consequently, we attach a metal that is more active (zinc anode) than bronze.

  Normally that is all the protection required. However, periodically a situation arises in which the zincs deteriorate at an accelerated rate, and the remaining underwater metal fitting are in jeopardy. This may be the result of a broken bonding wire, stray current from a short in the DC system or AC stray current corrosion.

  Tranquil Waters can provide you with a corrosion survey to help determine the cause of excessive zinc loss or deterioration of through hull fittings.

Other Services

 

Audio Gauging

  We are periodically called upon to help establish the deterioration or “wastage” in aluminum and steel shell plating, structural members and tankage. Using a Cygnus 2 muliple echo digital thickness gauge, readings are taken over the steel or aluminum hulls' external bottom plating. Prior to audio gauge measurements, a visual inspection iscarried out both externally and internally where accessible. Any signs of damage or previous repairs are noted.
  Special attention is paid to areas that are known to be susceptible to corrosion; such as tank margins, bottom of bilges, chain lockers, plating beneath engine room batteries, compressors and heads.
  Audio gauging can usually be carried out over good clean paint,
but requires the removal of rust scale, dirt and marine growth.

Corrosion in Boats

  The maritime world is a hostile environment to the various components of a vessel. Wooden structures are subject to rot and terredo (shipworm) damage. Plastic deteriorates from ultraviolet rays, and metals from corrosion

  Tranquil Waters can provide you with a corrosion survey to help determine the cause of excessive zinc loss or deterioration of through hull fitting

Restoration and New Construction Consultation

  On occasion, we are contacted to help with guidance in the construction of new vessels, and the reconstruction of traditional vessels.

  In the case of a newly built vessel, we will create a scope of work to identify the frequency of inspection during the major steps of construction. Upon completion of each step a detailed report of progress and any deficiencies noted will be generated. Once the vessel is complete, we will perform a final survey and inspection of all its systems prior the time the buyer takes ownership. Our most recent project was a 50’ wooden framed, cold molded, catamaran sailing vessel, which, upon completion, was sailed to the Virgin Islands.

 

  Vessel restoration provides a different set of challenges.
Typically they are old and wooden, and suffer from the various forms of degradation unique to wooden hulls;  from worm damage and decay, to degraded fasteners and iron sickness.

  We recently completed work on a 114’ Baltic Trader built in 1948, in which 80% of the planks on the starboard side and 30% on the port side were replaced. The remainder of the planks were refastened. The work was performed in a local boatyard by men, who when the day was done, knew that this was not your typical wooden sailing yacht, as each plank was 9" x 3 ¼” white oak.  The vessel has recently sailed across the Atlantic and is presently berthed in La Rochelle, France.

 

 

 

Arbitration

 Arbitration takes place when a difference of opinion is expressed with regard to a repair or insurance claim. Because a court appearance can be expensive and time consuming, arbitration is a method to resolve disputes without involvement in the court system. It provides a greater degree of control of the schedule in a less combative atmosphere. We will act as your representative to arbitrate or settle your claim to the best of our ability.

 

 

 

Marine Surveys - Tranquil Waters, Virginia