How to bolt aluminum without galvanic reaction

[bbenkaz]

How does a person bolt aluminum pieces togther ie my transom boards and corner pieces without the dissimliar metals reacting? I guess stainless steel bolts would be best. Is there any way to prevent the reaction?
thanks8)

 

[Chris1956]

Re: How to bolt aluminum without galvanic reaction

Galvanic corrosion will only occur underwater in salt water. Can you use aluminum rivits or bolts? If not use SS bolts, and install a zinc anode.

 

[bbenkaz]

Re: How to bolt aluminum without galvanic reaction

I can't use rivets in these places what is a zinc anode and how do I install it?
Thanks

 

[bbenkaz]

Re: How to bolt aluminum without galvanic reaction

do I need a zinc anode if it is freshwater?

 

[bbenkaz]

Re: How to bolt aluminum without galvanic reaction

never mind figured it out thanks

 

[Bondo]

Re: How to bolt aluminum without galvanic reaction

Just use SSteel bolts,+ screws,....

For what You're doing,..... There'll be No Problems......

 

[Bob_VT]

Re: How to bolt aluminum without galvanic reaction

There have been people who coat the bolts with grease then tighten them so there is grease in the hole with the bolt. Other people have coated the bolts with 4200 or 5200 to keep them sealed.

Indiana does not have too much salt..... maybe road salt.

 

[Dunaruna]

Re: How to bolt aluminum without galvanic reaction

[colour=blue]

Galvanic corrosion will only occur underwater in salt water.

Sorry Chris, but that is not correct.

Galvanic corrosion is an electro-chemical reaction, it will occur in any medium that conducts electrons. The only water that does not conduct, is pure water. Lakes and rivers are full of impurities - namely minerals.

 

[Chris1956]

Re: How to bolt aluminum without galvanic reaction

Dunarama, You are correct. What is the ratio between salt water and river/lake water, in terms of galvanic corrosion?

 

[bbenkaz]

Re: How to bolt aluminum without galvanic reaction

Guess I didn't figure it out. Is it safe to assume that below the waterline I should paint the aluminum surface to which the bolt is touching maybe even put some something or other on the bolt and above the water line will I be fine just using stainless right on the alum? Darn electrons need to stay put when I need them to.d

 

[Chris1956]

Re: How to bolt aluminum without galvanic reaction

Painting (with non-metallic paint) is better than having naked metal, underwater. If you paint with regular copper based antifouling paint, it will eat the aluminum faster.

 

[Bondo]

Re: How to bolt aluminum without galvanic reaction

I Think you're Over-engineering this alitte bit,.....

On a 12' Tinny, that isn't going to be moored in a "Hot" marina,........

Please refer to My post above,................


This is Ben's project,... Nice little boat...

 

[Saskatoon2005]

Re: How to bolt aluminum without galvanic reaction

Find a good aluminum paint and use it...better than nothing in the way of protection.

 

[Dunaruna]

Re: How to bolt aluminum without galvanic reaction

[colour=blue]

Dunarama, You are correct. What is the ratio between salt water and river/lake water, in terms of galvanic corrosion?

I don't know the answer to that but I don't think there is an accurate formula to make such a calculation because the impurities in fresh water would differ from location to location. Also, the physical surface area of an anode in relation the surface area of nobles would greatly affect the reaction, and every boat is different........................... := :/

 

[Chris1956]

Re: How to bolt aluminum without galvanic reaction

Dun, The point I was making is that although Galvanic corrosion occurs in lake and river water, it is so much less than salt water, it can be ignored for the most part.