Aluminum on Copper

[Lurch16th]

Has anyone had a problem with aluminum foil against copper causing corrosion?

I'll soon be insulating my copper pipes and sidearm and may use foil lined foam or something similar.

 

[A. Stanton]

I know in electrical wiring, if you mix the two, you can get big problems.

 

[Geez]

Treated lumber has copper chromate (I think) in it and it will eat aluminum right up.

 

[Beefie]

In pluming they sell fittings to connect two different kinds of metals, I think that alum causes copper to corrode and your wall thickness gets thinner. Not good if you have pressure behind it.

 

[Lurch16th]

Thanks for the advice, before i was about to do smething stupid.

 

[Geez]

In pluming they sell fittings to connect two different kinds of metals, I think that alum causes copper to corrode and your wall thickness gets thinner. Not good if you have pressure behind it.

Called galvanic corrosion, when copper pipes are coupled with galvanized ones. Same principal with other metals.

 

[Crofter]

Just keep the foil backed insulation away a bit from the copper and make sure it is dry. Make an initial wrap with just glass wool. No moisture, no electrolyte, no electrolysis!

Where the dissimilar metals on the activity scale are connected and you have mineralized or conductive water, corrosion can be rapid but I dont think it will be an issue for your application.

 

[habanero]

Just keep the foil backed insulation away a bit from the copper and make sure it is dry. Make an initial wrap with just glass wool. No moisture, no electrolyte, no electrolysis!

Where the dissimilar metals on the activity scale are connected and you have mineralized or conductive water, corrosion can be rapid but I dont think it will be an issue for your application.

I have to agree; as long as the metal junction wasn't wet all the time I doubt there would be enough corrosion to ever cause a problem. But I also agree that an initial wrap of glass wouldn't hurt anything and would be good insurance.

 

[Lurch16th]

Thanks for all of the tips. I'll start on it this a.m.