The Blonde Zinc Replacement

[Sir Rondo Normal]

Apply the threadlock to the screw before you go under. Let it set up, then it's like a nylock nut

[sy_gilana]

Hiya Sailorchick, As I have read several of your posts before, I know I am speaking to a peer or senior, in terms of engineering.

I have a 11 pound anode bolted into the floor of my seachest, I have magnesium ones in the bottom of my bilges in case of a leak of any type of water. I have anodes in my holding tank. I'm with you totally on this one.
Theoretically.

Now allow me to comment as a sailor, steel boat owner, diver, and Mr Fixit for a lot of boats over the last 14 years. Get a prop anode on there asap. Get ready in the water, have someone assist by handing you the allen? bolt inside the anode, head down with the allen key inserted. Use Loctite on the threads a good coating, and dive and insert it. The loctite will only set after a while, it requires O2 to go off. The anode will fall off, but the bolt will be there, and you can break it out again. Better yet it will rattle and tell you its time to change it.

I like your thinking.

[zeehag]

i adapt my collar zincs to use a lock washer so they dont fall off--when i dont do that, they go away and cause bad vibration---mine doesnt use a prop end zinc--just the collar. i have only had one fall since i began using lock washers with em

[fstbttms]

Originally Posted by Capt Wraun

Apply the threadlock to the screw before you go under. Let it set up, then it's like a nylock nut

No, it's not. Normal threadlocker requires oxygen to work. Pre-applying it to parts to be assembled underwater does is not effective. To my knowledge the only product that can be pre-applied to parts and then assembled underwater is Loctite 248 (which I have only found online.) This from one of the parent company's engineers.

http://www.amazon.com/Loctite-QuickS.../dp/B000132VH6

[Sir Rondo Normal]

Originally Posted by fstbttms

No, it's not.

Ya... it is "like" as in similar to a nylock nut.
That is what loctite does, mimmicks a nylock nut.

Originally Posted by fstbttms

To my knowledge the only product that can be pre-applied to parts and then assembled underwater is Loctite 248

Sorry for being too generic. Use Loctite 248

[noelex 77]

Threadlockers, like loctite, are anerobic glues. They set in absence of oxygen.
Establish a good metal metal metal bond and they will set.

Be careful when using these products you do not inhibit the electrical conductivity between the anode (zinc) and the metal ( such as the prop) that wish to protect.
Insulating the zinc, to prevent wastage, around the screws is preferable IMHO.

[sailorchic34]

Just FYI, thought I would measure the voltage between the prop shaft and the wire to the sea strainer zinc. Based on my trusty $12 voltmeter I get 11 millivolts with negative being toward the sea strainer zinc.

I also decided to check the potential directly at the zinc (with the wire and sea strainer cover removed) to the prop shaft and got the same reading

Of course what I need to do is hang a zinc on a wire over the side and measure the voltage between it and the prop shaft... So more experimentation is required.

But I am getting a voltage potential which is nice. It tells me that the Zinc is in circuit and doing its mojo.. Just not sure what the normal reading should be in fresh water..

[Jim Cate]

Actually guys you have it backwards about Loctite: it is an anaerobic adhesive. This means that for it to cure oxygen must be EXCLUDED from its surface. It must also be in contact with an active metal ion surface as well, but it is the exclusion from oxygen that triggers the reaction.

Think about it -- it stays liquid in the bottle (always at least half full of air, 'cause they only fill them half way for just that reason). It stays liquid when you apply it to the surface of the fastener. Then when you assemble the fastener and prevent air from getting to the Loctitie it sets up.

I'm not familiar with their 248 and can't comment upon its properties...

Cheers,

Jim

edit: oops, I see that Nolex beat me to the punch here!

[Sir Rondo Normal]

This is like a union meeting. An awful lot of talk for such a simple fix

[sailorchic34]

Good think I did not start an anchor thread. But I know better then that.

BTW, checked the abyc papers and found in salt water you want 200 millivolts difference between the anode and that being protected. Still looking for the fresh water readings..

http://www.abycinc.org/committees/E-02.pdf

[fstbttms]

Originally Posted by Jim Cate

Actually guys you have it backwards about Loctite: it is an anaerobic adhesive. This means that for it to cure oxygen must be EXCLUDED from its surface. It must also be in contact with an active metal ion surface as well, but it is the exclusion from oxygen that triggers the reaction.

Think about it -- it stays liquid in the bottle (always at least half full of air, 'cause they only fill them half way for just that reason). It stays liquid when you apply it to the surface of the fastener. Then when you assemble the fastener and prevent air from getting to the Loctitie it sets up.

I'm not familiar with their 248 and can't comment upon its properties...

Cheers,

Jim

edit: oops, I see that Nolex beat me to the punch here!

You both are correct, of course. In my defense, I have been brewing/drinking beer since about 10:00 a.m.

In any event, according to the manufacturer (whom I contacted after participating in a similar thread, maybe on this forum), Loctite 248 is the only thread locker that can be applied topsides and assembled underwater.

[LeaseOnLife]

The loctite 248 works underwater because it is a paste. The 'normal' blue loctite 242 is a thin fluid and washes away too easily in the water.

[Sir Rondo Normal]

lmao, the girl is talking technical and the guys are arguing over which goop to use.

[LeaseOnLife]

Originally Posted by zeehag

i adapt my collar zincs to use a lock washer so they dont fall off--when i dont do that, they go away and cause bad vibration---mine doesnt use a prop end zinc--just the collar. i have only had one fall since i began using lock washers with em

Lockwashers won't help on the prop-zinc: The lockwasher works against the underlying material, the zinc, which will be gone, then the lockwasher can't work. On the collar zincs, I use lock-nuts.

[zeehag]

i have yet to use locktite on my zincs--a lock washer usually is sufficient.
i dont know much about the prop end zincs--but the collars do well with lock washers applied.