Tech Tour Seminar Series

forestsaintregisOil and Offshore

Nov 8, 2013 (4 years and 2 days ago)

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Tech Tour Seminar Series

Scott de Recat


Derema Group

Corrosion 101

What is Galvanic Corrosion?

When a metal is immersed in an electrolyte (salt, brackish, or fresh water) small
electrical cells begin to form on the metal’s surface as a result of a chemical
reaction.


In time, the metal becomes polarized and material is lost from the anodic pole
of these cells. This causes the damage we know as galvanic corrosion.


An even stronger effect is produced when two different metals are electrically
connected in the same electrolyte.

Corrosion 101

CATHODIC

(LEAST ACTIVE, MORE NOBLE)

THE MORE SPACE YOU
HAVE BETWEEN METALS,
THE MORE ELECTRICAL
CURRENT IS DERIVED

ANODIC METALS

(MOST ACTIVE, LEAST NOBLE)


M III
-

Mg (
-
1450 mV)

M II
-

Al

M I
-

Zn

Galvanized Steel

Aluminum

Mild Steel

Iron

Tin

Bronze

Brass

Nickel

Copper

Stainless Steel

Silver

Gold (+1420mV)

The Noble Scale

Corrosion 101

Composition

MI

Zinc Alloy

MIL
-
A
-
18001K

MII

Aluminum Alloy

MIL
-
A
-
24779 (SH)

MIII

Magnesium Alloy

AZ
-
91
-
D





Cadmium

0.025%
-
0.07%

--

--

Copper

0.005% Max.

0.004% Max.

0.030% Max.

Iron

0.005% Max.

0.090% Max.

0.005% Max.

Indium

--

0.014%
-
0.020%

--

Lead

0.006% Max.

--

--

Mercury

--

0.001 Max.

--

Silicon

--

0.08%
-
0.20%

0.10% Max.

Nickel

--

--

0.002%

Manganese

--

--

0.15%
-
0.50%

Magnesium

--

--

Remainder

Aluminum

0.1%
-
0.5%

Remainder

8.3%
-
9.7%

Zi nc**

Remainder

4.0%
-
6.5%

0.35%
-
1.0%


**”MI Zinc anodes have a zinc purity of 99.995%

Specifications

MI

Zinc

Alloy

MII
Aluminum
Alloy

MIII

Magnesium

Alloy

CAPACITY, ampere
-
hours per pound

355

1225

500

EFFICIENCY (t est)

95%

94%

50%

CONSUMPTION, pound per ampere
-
year

24.5 lbs

7.6 lbs

17.5 lbs

POTENTIAL (reference Cu/CuSO4)

-
1050mV

-
1100mV

-
1450mV

Martyr Anode Alloy Breakdown

Corrosion 101

3 Different Anodes for 3 Different Water
Environments

There used to be only 1 anode type


Zinc. But over many years OEM’s, boat
builders and the general boating public realized that there were too many
variables when it comes to key boating areas and proper protection and
thus the evolution of 3 different anode alloys.

Corrosion 101

3 Different Anodes for 3 Different Water
Environments

Zn



Salt & Brackish Water



Fresh Water Only!



Salt Water Only!



Does not work in fresh & brackish water



Very Heavy and Shiny



Looks “sandblasted” as it corrodes.



Readily Available.


Al



Very Light, Dull Silver in Color



“Pits” as it corrodes.



Available in Commercial & Pleasurecraft lines

Mg



Extremely light. Dark Grey in Color



Available in Pleasurecraft only



Used by most OEM’s



Does not work effectively in pure fresh water



Cannot be used in salt or brackish water

Corrosion 101

Recent News
-

Anodes & The Environment

Corrosion 101

Recent News
-

Anodes & The Environment

WA DOE Boatyard General Permit
Guidelines


Page 14

Corrosion 101

So now what are your options?


Aluminum Anodes
-

Benefits


Contain No Cadmium. Primary elements are Aluminum and Indium
which are non
-
toxic


Better efficiency and performance vs. Zinc


Improved corrosion protection


Reducing the quantity of anodes required


Longer performance life


Lighter in weight then Zinc anodes


Less costly than Zinc anodes

Martyr Brands them as “Cadmium
-
Free” MII Anodes


Other companies offering Aluminum Anodes include



Performance Metals, Sea Shield and Reliance





Corrosion 101

Who’s using Aluminum Anodes


US Navy


Canadian Navy


US and Canadian Ferry Fleet


Oil and Gas Industry


Offshore drilling platforms


Leading dock manufactures world wide


All US/Japanese engine manufacturers



Mercury



Volvo



BRP



Honda



Yamaha





Corrosion 101

What has been written about Aluminum vs. Zinc?

Seaworthy
/

Boat US Standards:

“Below the waterline, when you have a stainless steel shaft and a
bronze prop, which can’t be isolated, you’ll need an anode


either zinc, magnesium or aluminum


that will be sacrificed to
save the fitting. Zinc can be used in saltwater; magnesium can be
used in freshwater (never in salt or brackish water);
but the most
widely affective anodes these days are being made of
aluminum, which can last up to 50% longer, and remain active
in brackish and saltwater
. How, you may ask, does an aluminum
anode protect an aluminum outdrive? The answer is that an anode
is made with an aluminum alloy that is significantly different (more
anodic) than the alloy used on an outdrive.”

Corrosion 101

What has been written about Aluminum vs. Zinc?

West Advisor: Getting rid of Cadmium and Zinc

“Zinc and cadmium are elements used in traditional salt
-
water
anodes that are suspected of causing environmental damage.
CMP Global has re
-
formulated their product, removing these alloys
for safer more “green” anodes. A rare bit of good news for the
boater: these new formulations actually work better! They’re lighter
and last longer, so they’re a plus for your boat and for the
underwater life in your marina”.

Corrosion 101

What has been written about Aluminum vs. Zinc?

Marine Log


April 2012 Issue

Crowley Marine


VP of Engineering


Bill Metcalf

Crowley’s vice president, Engineering, and
a 30
-
year Crowley veteran, Bill Metcalf
says the company has used aluminum
anodes “since before I joined the
company”. The reason? “it’s based on
utilization. The aluminum anodes will last
longer in the water, they have a better
performance life, say Metcalf”.

Corrosion 101

What has been written about Aluminum vs. Zinc?

Artist, Sport Fishing Professional, Environmentalist, Editor

Guy Harvey


Summer 2012 Guy Harvey Magazine


Corrosion 101

FAQ’s about Aluminum vs. Zinc?


Can I use aluminum anodes on my aluminum boat?



Why doesn't Martyr produce aluminum pencil anodes?



Can I mix aluminum anodes with zinc anodes?

Corrosion 101

What to look for in Anode Protection

Quality


MIL Spec Products are critical


Reliable Performance.


Products produced in an
ISO 9001 Certified Facility


In
-
house lab testing ensures adherence to the Mil Spec
alloy material (zinc, aluminum & magnesium)


Approved vendor to many OEM, Government & Military
organizations around the world

Product Availability
-

Bulk & Packaged Anodes


Product availability in all 3 alloys (only manufacturer to do so)


Products available for most popular marine engines/ systems


Key boatyard products including commercial plates


2 choices of shaft/ rudder/ collar hardware


hex & slotted in stainless


Over 50 new products launched every year (over 400+ parts now!)

Corrosion 101

What does Martyr have to offer?

Customer Service/ Support


Factory & Rep support in the field


Factory personnel trained in Corrosion Control through NACE


Worldwide distribution network


Fisheries Supply


Diversified Marine Products


Redden Marine


Port Supply


Large range of support material available

Corrosion 101

Did we mention support…


Catalogs

Posters/ Flyers

POP Items

Website

www.martyranodes.com


www.martyranodes.com


Website

www.martyranodes.com


Website

www.martyranodes.com


Website

Corrosion 101

Did we mention support…


Custom FAB’s
Sell Sheet
Available

Just ask!

Corrosion 101