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Hi Guys, I’m planning on installing a new leaning post this week. Using stainless steel screws to attach the aluminum leaning post to the deck. Any info or any tips you can give me regarding using stainless with aluminum.
Someone once told me to dip the screws in a product called tef-gel? Or something that sounds like that.
i've used SS fasteners all over my aluminum boat, and have had zero corrosion issues in over two years of heavy saltwater use. one thing i did do was make rubber "gaskets" out of an inner tube where i have large surface area contact (t-top pads, ss antenna mount, etc) but for the very limited contact you'll have with your fasteners i can't see that it'll be a huge issue. others may disagree...?
one thing i do is give a spray of an anti corrosive (boeshield, crc, etc) to the screw heads every now and then.
quote:Originally posted by Canazes9: What cgrand said, I have stainless all over my aluminum boat - three years now, no corrosion issues ...
You mean ...YET ! When it does show, and it will, you may be sorry. Personally I think to do nothing is irresponsible and foolish advice.
I once took apart the console on a Lund aluminum boat and the entire aluminum dash and on the backside of the frame where you couldn't see was corroded out like what happens to a zinc anode ... no strength left in the metal either. On the outside, the aluminum looked fine ... but it had lost its structural integrity.
Why take any chance when the solution is so simple?
On threads I use OMC Triple Guard grease. If there is a large portion of threads that go thru aluminum that aren't being used (like an ovalhead bolt thru a thick aluminum flange) I put heatshrink on the bolt over the head and heat it. Then I trim the heatshrink to look "pretty", but make sure to leave it on the "V" portion on the fastener head. Simple !
I also use nylon washers under a SS screw if securing an aluminum plate. One could use eletrical tape or rubber, as stated, just something to isolate the 2 parent materials.
Galvanic corrosion due to dissimilar metals will happen whether or not exposed to saltwater and salt air, but it will be accelerated in those conditions.
My opine ... take simple and quick steps to prevent damage .
What you are doing is certainly not bad, Reel Raskal, but to consider contrary advice foolish and irresponsible is to overstate the case. Aluminum is a bit different than most other metals when it comes to galvanic corrosion--although aluminum it is a very active metal, an anodized coating is a very effective dielectric insulator, so that galvanic current usually won't flow (or won't flow for long before any unanodized material oxidizes).
Yes, it's nice practice to use insulating bushing and washers wherever dissimilar metals join, but it's also quite possible that Canazes9 will see no galvanic corrosion in 30 years, let alone 3.
You'ld think that someone that had such a great reputation for making saltwater aluminum boats over the last 25 years would have known better than to do something that stupid...
Reel-Rascals - there really isn't any similarity between my boat and a Lund. Lund isn't built for saltwater use - mine is. All the stainless on my boat was put there by Scully. I'm willing to take the chance.
Location: Quebec, Canada and Pirates Cove, OBX, NC
Posts: 17,813
Stainless and Aluminum?
The real question is what type of aluminum is your boat made from. Marine (salt water)grade aluminum (like the Coasties and Navy use) is very resistent to galvanic corrosion.
Many boat companies use aluminum not designed for marine use (cheaper) and they can corrode quickly.
The second question is quality of stainless steel fittings you use.
Marine grade aluminum and high quality stainless will make a high quality product that will last for a long time.
The only problem with using O rings is that they split and spread when placed under high torque loads.
Stainless and Aluminum? 
I too do the aluminum/SS tango....no prblems here. For a gasket, I use O-rings
Boston Whaler, "MUMBLER", 24' Outrage, twin 175 HP Evinrude Ocean Pros. 
Snowball, the cat... 
! When it does show, and it will, you may be sorry. Personally I think to do nothing is irresponsible and foolish advice. 
.
mea culpa. 
