SO 42.1 1994 Life Line Stanchion Mounts

[bsafreed]

All, I've discovered the bolts used to secure the lifeline stanchion bracket to the toe rail are made out of aluminum.

In removing the older bolts most broke apart as they were heavily oxidized.

A good thing to discover as I'm going through all systems to perform upgrades/replacements. I'm surprized Jeanneau would have used aluminum bolts with a SS backplate under the deck.

I'm systematically drilling out each of the original bolts and replacing with 2" 1/4 20 SS bolts/lockwashers/nuts. (easy to drill out as the metal is soft).

I'm curious if others have encountered this issue.

Brian

[joker64]

No, but I am getting ready to. Let you know what I find out.

[jacquesmouton]

I would think that Jeanneau used aluminium bolts in order to avoid electrolysis between aluminium stanchion and ss bolts. The idea is that water should not have found its way along the bolt. If you decide to use SS Bolt try to avoid direct (electrical) contact between ss and aluminium using nylon washer or similar.

[aussieodyssey]

Or you could use a product called duralac .It is quite thick and yellow in colour ,it is for preventing electrolosis with disimiler metals
Greg

[bsafreed]

Greg, Thank you for the suggestion.

I'm searching for Duralac in the USA and have yet to find a vendor. Some sailing blogs mention Lanacote.

Not sure if they are comparable but I'm going to check into both as I have several projects that have SS to Aluminum connections.

Best Regards,
Brian

[sitara]

I have occasionally over the years used Duralac when attaching metals to aluminium and it certainly seems to work. It dries to form a permanent barrier and certainly no outward signs of electrolysis. My experience with lanolin based materials is that they will reduce corrosion but are not that permanent

[bsafreed]

All, I spoke with the inventor of a product called Tef-Gel and he said it's superior to Lanocote and Duralac. His name is Bob and he was very informative on the chemistry of dissimilar metals and marine applications.

12 months ago I've used Tef-Gel when servicing the gooseneck as the SS screws in the SPAR were oxidizing the aluminum treads. I was not sure if it could be used when bolting SS to aluminum but its main purpose is to coat and prevent salt water or air from entering into the joined surfaces.

From his web site: www.tefgel.com/contain.php?param=tefgel_infor

The function of Tef-Gel in eliminating dissimilar metal corrosion is the elimination of electrolytes from entering the interface of the metallic surfaces. Tef-Gel paste contains 40% PTFE powder and 0% volatile solvents, no silicones or petroleum solvents to evaporate, which would leave voids for electrolytes to be drawn into creating a galvanic cell. When both surfaces are coated and mated with Tef-Gel there are no voids for electrolytes (saltwater) to be drawn in by capillary action over extended periods of time.

Best Regards, Brian

[leolind]

Over 40 years we have used lanolin, Duralac and Tefgel. Lanolin is OK but it sticks and lasts less than Tefgel, and is very affected by temperature (from runny to very hard). Tefgel is best for fasteners that you might need to remove within a year (but it cannot be painted over). Duralac is the best for stopping corrosion permanently (we have stainless screws in aluminum and no corrosion after 20 years). It dries like paint to somewhat lock the crews in place, and can be painted over. For unpainted places, the only disadvantage is the yellow colour, although one can wipe off most of it, leaving only a tiny yellow ring visible around the screw heads.

Not finding any source of Duralac in the USA, I brought in 5 tubes and am now selling 3 on Ebay.
Leo

[Donrob]

I have used Duralac for many years for stainless steel screws and rivets in aluminium and i have had no corrosion whatsoever. The one I buy comes in a tube, is yellow in colour and can be quite messy (its like a thick oil based paint). Not sure if there is a propriety solvent to remove the excess.

[windspeak]

There is quite a lot s/steel through aluminium on my 02 ds43 and a tube of the yellow stuff lives in my general tool bag and gets used often along with a small bottle of acetone to damp a cloth
will clean up any residue a tube of big wipes ( most decorators supply stores)are great for hands and will remove just about anything without attacking the skin handy when the tea sarnies arrive

[bsafreed]

Leo, please send me your eBay posting link. It will be good to try this out...
I'm also a fan of butyl tape on all deck fittings .thanks, Brian