With Painting Season in full swing, I thought we would look at the basics of corrosion protection. 

  

Where does it all start?  Those reddish bubbles that show up in the cracks in your paint on the bulkheads and deck are an indication of a chemical reaction happening below the surface.

  

Rust is a general term for a series of iron oxides. The term is applied to red oxides, formed by the reaction of iron and oxygen in the presence of water or air moisture.   Given sufficient time, oxygen, and water, any iron mass will eventually convert entirely to rust and disintegrate.

  

Rust is permeable to air and water, therefore the iron below the surface continues to corrode. Rust prevention thus requires coatings that preclude rust formation.

  

The rusting of iron is an electrochemical process that begins with the transfer of electrons from iron to oxygen. The rate of corrosion is affected by water and is accelerated by electrolytes such as salt. 

  

So how does it start?  Like anything else, the right conditions have to be in place.  In a marine environment these conditions are more than abundant. 

  

The goal of your paint system is to isolate the steel  from the environment.  The slightest crack in that paint system or "holiday", a spot not coated, will allow the start of corrosion.  Since as we said above, rust is permeable to air once the reaction starts, the reaction will continue in the iron penetrating below the surface and beneath the surrounding coated areas.

  

  

Power wire brushes, needle guns, grinders and sanders can be used to remove loose paint and built up rust and scale.  Care should be taken, particularly with power wire brushes, not to polish the metal surface as this will reduce the profile which the primer needs to adhere to it.

 

A fresh water rinse is important to remove any salts left on the surface.

 

A chemical rust inhibitor such as Chemprime is then applied.  A rust inhibitor is basically Phosphoric acid.  It is used as a "rust converter", by direct application.  It converts the reddish-brown iron oxide, Fe2O3  (rust) to black ferric phosphate, FePO4.  The black phosphate coating can be left in place, where it will provide moderate corrosion resistance.

 

PPE requirements for Chemprime:

Wear chemically protective gloves, boots, aprons, and gauntlets to prevent prolonged or repeated skin contact. Wear protective eyeglasses or chemical safety goggles, per OSHA eye and face protection regulations (29 CFR 1910.133). Contact lenses are not eye protective devices.  Appropriate eye protection must be worn instead of, or in conjunction with contact lenses. (MSDS No. 0100)

 

Primer paint is then applied to further prepare the surface for the top coat.  Priming ensures better adhesion of paint to the surface, increases paint durability, and provides additional protection for the material being painted.  Primers for marine applications typically contain sacrificial zinc to help protect against corrosion.

 

Typically, Higman boats apply two primer coats. 

 

The topcoat used by our vessels is an Acrylic enamel which dries hard and sooth.......Now the boat looks great and is protected from corrosion!

USCG Rules of the Road Questions

 

INLAND ONLY You are on a vessel that the Secretary has determined cannot comply with the spacing requirement for masthead lights. What is required in this situation?

a. The vessel must carry only the lights that comply with the rules; the others may be omitted.
b. The vessel's lights must comply as closely as possible.
c. The vessel must be altered to permit full compliance with the rules.
d. An all-round light should be substituted for the after masthead light and the stern light.

 

INLAND ONLY You are proceeding up a channel in Chesapeake Bay and are meeting an outbound vessel. There is no current. You MUST __________.

a. keep to that side of the channel which is on your vessel's port side
b. stop your vessel, letting the outbound vessel sound the signals for meeting and passing
c. propose or answer one- or two-blast whistle signals given by the other vessel if passing within 1/2 mile
d. give the outbound vessel the right-of-way

 

INLAND ONLY While underway and in sight of another vessel a mile ahead you put your engines on astern propulsion. Which statement concerning whistle signals is TRUE?

a. You must sound three short blasts on the whistle.
b. You must sound one blast if backing to starboard.
c. You must sound whistle signals only if the vessels are meeting.
d. You need not sound any whistle signals.

 

INLAND ONLY A vessel engaged in public safety activities may display an alternately flashing red and yellow light. This special light may be used by a vessel engaged in __________.

a. search and rescue
b. restricted in ability to maneuver
c. not under command
d. river bank protection

 

INLAND ONLY A vessel engaged in public safety activities may display an alternately flashing red and yellow light. This special light may be used by a vessel engaged in __________.

a. river bank protection
b. conducting submarine operations
c. firefighting
d. law enforcement

Indianola's streets were soon bursting at the seams as wharfs and large warehouses began appearing on the water front.  Included in the businesses was a shipyard that built coastal schooners.   By the mid 1850's, the port became one of the leading ports in Texas with the thought that it would overtake Galveston in trade. 

 

In 1875 a devastating hurricane leveled much of the city.  At least 270 people lost their lives and hundreds of buildings were washed away.   An effort was made to rebuild the city during the next 10 years but Indianola was once again washed away in 1886.

 

The town was never rebuilt.  

 

Unfortunately last week one of our Relief Captains lost his house to a fire.  Initial reports from the Fire Marshalsindicate that the fire came from the laundry room and could possibly have been a dryer fire. 

 

Since this may have been a dryer fire, it reminded me of the time I had a simular situation.  At the time I lived in an area abundant with rodents.  The screen on the vent hood got knocked off.  This presented a perfectly warm, dry place for some mice to build a home.  While drying some clothes, the mouse nest burst into flames in the vent hose.  Fortunately, we were able to put the fire out before it got out of control. 

 

This was a very real awakening to why you should always keep your dryer vents clean and unobstructed. 

 

Have a great and very safe week!   

 

Sincerely,