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Topic: FYI-- (Read 5 times) previous topic - next topic
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FYI--
Yahoo Message Number: 110199
Diagnosing Electrolysis:

The term electrolysis generally describes a condition where an aluminum or galvanized metal roof skin corrodes from underneath. The metal acts as a catalyst causing the adhesive bonding it to the plywood to decompose. Some of the decomposition products then react with the metal causing pitting and loss of adhesion. This condition will continue at an unpredictable rate until the catalytic effect of the metal is lost or the adhesive completely degrades.

Advanced stages of electrolysis can be recognized visually. Make a 2” T cut and bend the skin back.
If there is poor or no adhesion to the plywood and the underside of the skin appears mottled or rough then the electrolysis process has already begun. The beginning stages will be more difficult to recognize but will start with loss of adhesion and then progress to eroding the metal.

DO NOT apply Liquid Roof® to a roof diagnosed or suspected of having active electrolysis. The coating will eventually fail as the skin deteriorates from underneath. Removal of the metal skin is the only way to stop the electrolysis. When pitting or corrosion is only on the topside of the metal, it may be top-coated with Liquid Roof®.

Gini Free and Junah, canine xtrodinaire "Kooch" our little red home on wheels "Growing old is mandatory. Growing wise is optional."

[Non-text portions of this message have been removed]
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Gini Free and Junah, canine xtrodinaire
"CHERRYOTTE" our little red home on wheels
"Growing old is mandatory. Growing wise is optional."
 
Re: FYI--
Reply #1 –
Yahoo Message Number: 110202
Gini Free  wrote: "The term electrolysis generally describes a condition where an aluminum or galvanized metal roof skin corrodes from underneath. The metal acts as a catalyst causing the adhesive bonding it to the plywood to decompose. Some of the decomposition products then react with the metal causing pitting and loss of adhesion..." ---
 Is there a source for this information?  My understanding of "galvanic corrosion" and its causes are consistent with the information in this link:
 http://www.rvdoctor.com/2010/01/galvanic-corrosion.html

Perhaps the chemists/metallurgists/engineers on the board can provide expert commentary?

Joan
2003 TK has a new home