Does Loctite protect against galvanic corrosion?

[a64pilot]

Loctite works cause it seals the moisture and salt out, not because it a dielectric, cause I don't think it is? Just for Gods sake use the blue and not the red if you think your going to remove it, red can be tough may need more heat than a part can handle if it has plastic or similar on it.
A helicoil is invaluable for repairs, but it's a spring really, and a real insert is solid, an insert is better when possible

[model 10]

Originally Posted by a64pilot

, and a real insert is solid, an insert is better when possible

These things are hard to remove when damaged, think broken tap hard. Because of that I think the spring coil is better.

[Paul L]

Originally Posted by sailon46

The Germans in the UBoats put on everything Vaseline to prevent corrosion and galvanic issues between dissimilar metals. Ive used it everywhere I can, no corrosion anywhere.
Ernie

The war didn't last that long, fortunately.

I use Tefgel. It seems to work fine even after 10 years on a mast. The only issues I've had with it is bolts backing themselves out on occasion.

[a64pilot]

My first use of helicoils was drag bikes.
We used to turbocharge the ole Kawasaki 900 years ago and when we got deep into 8 sec territory, the gears in the transmission would climb over each other and "split" the case. That is they would pull the bolts out of the parent aluminum and strip all the threads out.
We installed helicoils and as the helicoil was of course larger in diameter than the bolt, it grabbed much more aluminum, no more split cases.
But I gotta think that SS spring that a helicoil is, is going to corrode into the aluminum worse than a bolt?

[Compass790]

I discovered Loctite 242 in the '70's to use on motorbikes. I can tell you it seem to do both jobs of stopping the fasteners from vibrating loose & stopping the corrosion from seizing them.I never install a fastener on an outboard engine without using it & it's a must on our single cylinder diesel.

[Steve Bean]

Has anyone here had any experience with Cosmoline?
I've heard of it being used to protect the inside of a Dutch steel boat, on bare steel.

[estarzinger]

Originally Posted by a64pilot

But I gotta think that SS spring that a helicoil is, is going to corrode into the aluminum worse than a bolt?

Couple things:

There are four levels of solution for an aluminum structure (from best to worst - just talking about corrosion here). . . (1) all welded, (2) thru bolted (not threaded) using phenolic (or similar) sleeves and washers, (3) threaded inserts set in 'permanent goop" (red loctite or similar), and (4) tapped machine screws set in 'removable goop' (e.g. In the spectrum of Tufgel to blue loctite).

There are two different types of corrosion concern. One is frozen fittings - if you use threaded inserts that is pretty much 100% avoided. The second is mostly cosmetic bubbling - really #1 above is the only way to 100% avoid that. You will see some cosmetic bubbling even on hard used harken's. But, in my experience, properly set threaded inserts will usually be better, and not worse than streight marine screws in goop.

I never had good data on which threaded insert was "best". I tended to use different types based on aluminum thickness and load, but would be interesting to have better insight into which type is best for which application.

[Captsteve53]

Guys Guys Guys -Why does any one not know about DUROLAC jointing compound, this is the ONLYthing to use when doing dissimilar jointing even to rubber/wood but especially with Stainless steel to Aluminium inclusive rivets and mast work,

This will stop ANY galvanic action /seal and lock bolts and parts together, it comes in tubes and cans (messy to deal with and sticks like s--t to a blanket).Also works as a great gasket maker/sealer

Its basically a Zinc Chromate paste (with additions) yellow in color, I Have used this and nothing else for over thirty years in bedding applications/mast building/engine work/boat building in general (probably eat it for breakfast if it wasn't rather toxic) is it obvious I love this stuff

Even after numerous years exposed to the elements there's never a hint of re action between materials

Check out here:https://www.whitworths.com.au/main_i...AbsolutePage=1

Not sure where to purchase in the US but every yacht/boat /ship should it in there tool box, Opinion over rated NO IT JUST WORKS!!!

[Davidhoy]

It seems Durolac is available online in the US from Fisheries Supply - https://www.fisheriessupply.com/sadd...nting-compound

[thinwater]

Originally Posted by Paul L

...I use Tefgel. It seems to work fine even after 10 years on a mast. The only issues I've had with it is bolts backing themselves out on occasion.

I've noticed that in testing. It is almost like anti-thread locker. Assemblies that would snug-up with any other grease were sometimes difficult to secure. Does it matter? I'm sure that depends on vibration and flexing.

[Captsteve53]

Official speel re DURALAC

Duralac is an anti-corrosive jointing compound for use between joints of dissimilar metals. It is in the form of a tough, flexible, yellow paste with low moisture permeability, and contains barium chromate in an inert filler matrix. The barium chromate is only very slightly soluble in water, so it remains in the joint, even in the presence of a considerable flow of water. It has a long useful life because it only becomes active in the presence of conditions which promote corrosion.
• Indispensable for the effective sealing of joints between dissimilar metals --- even very active magnesium alloys
• Effective at preventing corrosion at stress contact points in similar metals, such as rivets in masts
• Protects metals in contact with non-metallic materials such as wood, resins, rubber, etc.
• Especially useful in saltwater environments which exacerbate corrosive processes
• Conforms to specification DTD 369B

[barnakiel]

VASELINE ???

NO

It is never vaseline. Vaseline is quite the opposite - a conductive lubricant. Just what we are trying to avoid.

Cheers,
b.

[a64pilot]

Originally Posted by Steve Bean

Has anyone here had any experience with Cosmoline?

I've heard of it being used to protect the inside of a Dutch steel boat, on bare steel.

Cosmoline is a phenomenal preservative for steel. Used at least since WWII on military hardware, guns etc.
Par-al-ketone is a very similar product

[Cheechako]

Originally Posted by Steve Bean

Has anyone here had any experience with Cosmoline?
I've heard of it being used to protect the inside of a Dutch steel boat, on bare steel.

Yes it is used on a lot of metal items for the Military. Used on spare parts so they dont degrade in storage. The retail spray form is CRC 5-56. I used it extensively on the boat, especially metal /steel parts on the engine etc. keep in mind it stays just a bit tacky...
Vaseline, grease etc just wont stay for too long..... the reason I mentioned Lanolin or Lanocote earlier. Put some on your hand, you cant wash it off with water.

[thinwater]

Originally Posted by barnakiel

VASELINE ???

NO

It is never vaseline. Vaseline is quite the opposite - a conductive lubricant. Just what we are trying to avoid.

Cheers,
b.

A bold statement requires data back-up. Though it may not be a perfect insulator--and NOTHING will be once the fastener is tightened--it does not conduct much.

Second, I can think of several conductive greases that are very effective at preventing corrosion and seizing (no-ox-id is one). I'm not sure there is any evidence that being purely dielectric is better in this application. The most effective anti-corrosion greases contain additives that make them slightly conductive, but remember that we are speaking of conductivity far below anything you could measure. They are ALL effectively dielectric, in the commonsense meaning of the word.

So no, I could not find evidence that Vaseline is more conductive than other products in the running here, and no, dielectric properties alone are not proof of suitability. For example, Duralac is certainly not dielectric, yet experience shows it is very effective. I've also done side-by-side testing of dielectric and other greases for wash-off and dissimilar metals corrosion use ASTM methodology, and dielectrics were at the bottom of the pack of the pack. Search "Grease" in Practical Sailor for the back-up.

Vaseline would not be my first choice. Perhaps the greatest problem is the low melting point--it will run out as soon as the sun heats the aluminum. There are better options.