orgelpark lead corrosion 2016 02-06
TRANSCRIPT
Flentrop Orgelbouw
LEAD CORROSION
Restoring at the frontier of our knowledge
Lead corrosion
•Why is it a problem?•What is lead corrosion?• How can we avoid lead corrosion?• How can we repair the damage?
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Hamburg, 1588
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Alkmaar, 1645
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Alkmaar, 1645
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Alkmaar 1645
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Alkmaar 1645
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Why is it a problem?
• Loss of historic material• Loss of information• Loss of sound quality•Demo?
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What is corrosion?• Corrosion is an electro-chemical
reaction in which one material oxidizes and another reduces.
• Electro-chemical• Oxidation/Reduction• Two directions
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Balance
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Pourbaix diagram PbS
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Facts
Replacement pipefeet (mm)Year/division 1986 2004 2014RP 1045 40 865
HM 2537 1907 13989
BW 6825 0 16776
Ped 1321 157 3074
total 11728 2104 34704
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Why Alkmaar?
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Why Alkmaar?• Carbon dioxide from the gas
heating?• Almost no acetic acid, nor formic
acid• CH4 + 2O2 ® CO2 + 2H2O• CO2 + H2O ® H2CO3
• COLLAPSE
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How to avoid lead corrosion?
• Influence the balance (remove an ingredient)–water– oxygen– acid
• Sealing • Rinsing
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Rinsing
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How can we repair the damage?
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Replacing corroded metal
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Bovenwerk Prestant 8
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Bovenwerk Prestant 8
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Bovenwerk Prestant 8
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