Copper gasket sealant??

[bigtwin]

I was reading a prior post stating copper head gaskets shouldn't be used with an aluminium head or block.
last year I replaced the head gasket on my 1998 25hp Evinrude twin. During assembly I noticed the head bolts had sealant on them from the factory, so I cleaned them off and sprayed on fresh coat of copper gasket sealent on the head bolts. I also sprayed a thin coat on both sides of the head gasket, the head and the block, Where they mate with the gskt.
Is this going to be a problem? Do I have to worry about excessive corrosion even in fresh water?

 

[iwombat]

Re: Copper gasket sealant??

Personally, I wouldn't use it on an aluminum block. That being said, I'm not sure to what amount you can expect excessive corrosion due to the spray copper.

 

[bigtwin]

Re: Copper gasket sealant??

There is a lot of copper in the sealant, looks like you could spray paint a bass boat with the stuff.
I think I'm going to play it safe and replace the head gasket and clean every thing up.

 

[Dhadley]

Re: Copper gasket sealant??

In fresh water cooper isn't as bad as in salt water. Copper in salt water can and will turn an aluminum block into an Alka Seltzer tablet.

 

[F_R]

Re: Copper gasket sealant??

It's the impurities in fresh water that makes it conduct electricity (corrosion). Some is worse than others, but none is so bad as the cleanest salt water.

Years ago, my uncle bought a small aluminum boat and put it in his private lake in Ohio. Before summer was over, it sank. All the rivets dissolved. Seems there was some copper content in the aluminum rivets.

 

[Dhadley]

Re: Copper gasket sealant??

Ever see somebody paint an outdrive or gearcase with copper anti-fouling pait? What a mess!