wood + aluminum = pus?

[Shankster]

Friend of mine said he was removing the aluminum bulwarks from his 55' salmon seiner because there is a chemical reaction with the wood deck they are bolted to. He said both materials are deteriorating where they meet. Anyone know what's happening chemically? Some woods worse than others? Are there known no-nos when planning to marry wood to aluminum? He said the aluminum is high quality marine aluminum. Pus was the word he used to describe what was being formed.

 

[jimchere]

Re: wood + aluminum = pus?

Does the "pus" look like a white paste, almost the consistency of butter? That's aluminum in a highly corroded state from exposure to saltwater. There's no adverse reaction between aluminum and wood that I know of.

 

[mellowyellow]

Re: wood + aluminum = pus?

the wood is retaining saltwater and the saltwater<br />is causing the corosion IMO.

 

[vidar]

Re: wood + aluminum = pus?

it can be an elektric/galvanic prob also....damp wood is conductive....and if there is copper or simiilar metal in the wood...CORROSION bigtime..

 

[Uncle Dave]

Re: wood + aluminum = pus?

Is the wood treated? (such as pressure treated)<br />Some treated wood contains a copper compound. Seems that copper and aluminum do not mix too well. Similiar to using copper containing bottom paint on alum hulls.