Paste that Stops Corrosion Between SS and Aluminum ?

[Don Huseman]

I have been told that you don't use stainless steel bolts with cast iron keel. The galvanic difference will cause the stainless to eat out he threads. There is a paste that they use on stainless steel screws in aluminum mast that stops the corrosion between the stainless and aluminum. I have asked the company about it and they said that it stoped the water form becoming the elctrolite. I have lost the can of the paste and forgotten the name. It is not alumolast but it does the same thing.
If any body has any experiance with this materail then lets talk here.
Don Huseman

[witzgall]

I have used Lanocote with SS and Aluminum. Is this the stuf you mean? It is a dark brown waxy goop, that turns to liquid in heat.

Chris

[Vasco]

Lanolin will do it. I bought a jar from the drugstore (used as a base for all sorts of ointments) 25 years ago and still have lots. Put it on my shackle pins too. They'll hold tight but when you want it to come off, the pin is not frozen.

[skipmac]

If you want to go more hi-tech you can use Tef-gel. "Experts" report that it last longer and works better than lanolin.

I have lanolin and just bought a tube of Tef-gel to try so ask me in 5-10 years if the Tef-gel was better.

[anjou]

Back in the day when Messers Slingsby made gliders for the RAF, they were on a tight budget and had to use galvanised control cables, so they soaked them in Lanolin, which became waxy when dry and it lasted for years and years

[bounty hunter]

we have a lot of alloy boats in new zealand

this product

Duralac DTD 369B prevents Bi Metallic Corrosion DTD369B

is used a lot where different metals meet

[osirissail]

Lan-o-cote is anhydrous lanolin - same stuff that is organically in your hair and sheep's fleece. It is an economical way to ensure that ss bolts or any bolt/screw into a dissimilar metal will be removable years later. Tuf-gel does the same thing at a much higher price.
- - It is especially important in anything aluminum to stop the white powder corrosion that seems to "weld" aluminum parts together.

[Don Huseman]

the reason I was asking about the material was I could no remember that it was Tefgel. I want to use it on cast Iron keels and use 316 stainless steel studs in the iron. If this works , and I will be testing it for a year it could be a very nice improvment for keel bolt replacement. My business is keel bolt sistering and every now and then i get a castiron keel to do. If any body want to talk to me about keel bolt problems you can get me at: husemand <at> netscape <dot> net

[speedoo]

I have an outhaul slide, probably stainless steel, that has bonded to the aluminum boom. Can anyone advise a good way to loosen it up? I've tried hammering and no dice. There was a suggestion to soak in fresh water, have not tried it yet.

[Lodesman]

I have heard a mechanics' trick is to dip steel screws in milk of magnesia before threading them into alloy blocks/parts. Can't say if it works, but sounds plausible.

[ConradG]

corossion-X is a product used in aviation to help prevent aluminum from coroding. Regular antisieze paste also works well for trying to keep the aluminum from the stainless. But there is always going to be the potential for the metals to contact or the water to enter and sit causing crevasse corossion, which both metals are suseptible to even without contact. It seems unlikely that anything can stop salt water from being what it is, an electrolite, except by keeping it out which depends entirely on the integrity of a coating.
I am not clear on what the application is as the thread is titled SS and aluminum and you refer to ss and cast iron. In either case you might want to consider hot dipped galvanized steel fasteners as they are close to both cast iron and aluminum on the galvanic scale and any rust would be a good indicator that it is time to redo the coating (paint). And they are more tollerant of crevasse corossion

[ConradG]

Originally Posted by speedoo

I have an outhaul slide, probably stainless steel, that has bonded to the aluminum boom. Can anyone advise a good way to loosen it up? I've tried hammering and no dice. There was a suggestion to soak in fresh water, have not tried it yet.

PB Blaster from the autoparts store is the best penatrating oil I have found. Repeated aplications and the hammer might work. If not then heat can sometimes jar things loose from expansion and contraction but with aluminum you have to be careful. Most is a "T" designation and gains extra strength from it's temper. It also shows almost no signs before it is a pudle intead of a boom. Stainless will loose it's stainless properties if heated enough unless it is pollished up again (scotchbrigt will work)

[GordMay]

Originally Posted by Lodesman

I have heard a mechanics' trick is to dip steel screws in milk of magnesia before threading them into alloy blocks/parts. Can't say if it works, but sounds plausible.

I’ve heard old timers recommend Milk of Magnesia as a high temperature anti-seize.
Unflavoured MoM dries to Magnesium Hydroxide, a fine powder, which doesn’t deteriorate with heat (to about 1,200 deg. F).
A better high temperature anti-seize might be based on Boron Nitride, or White Graphite.

[ConradG]

Originally Posted by GordMay

I’ve heard old timers recommend Milk of Magnesia as a high temperature anti-seize.
Unflavoured MoM dries to Magnesium Hydroxide, a fine powder, which doesn’t deteriorate with heat (to about 1,200 deg. F).
A better high temperature anti-seize might be based on Boron Nitride, or White Graphite.

Wow, and magneseum is below even aluminum on the galvanic scale I believe....right by zinc.

[bewitched]

I've always used Duralac, but the last time I had my rig out, the rigger recommended something else - but I can't remember it's name!!

It was a lot more expensive - so must be good - came in a little syringe.