Water in the bilge - past zinc bolts?

Fishermark

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Regarding another post of mine - I'm glad to say I got my engine dried out and running. Now the underlying cause of the water in the bilge - it looks like it is coming in at the bottom of the transom / outdrive assembly. There are a couple of bolts that have what look like some zinc caps on them. When I fill the bilge with water it leaks out where these bolts are. Are these hard to replace? It is hard to get at the bottom of the transom area from inside the boat. I haven't tried looking too carefully inside... but are these zincs simply caps on the bolt heads, or are they integrated into the bolts themselves? (This is a 1986 Alpha one).
 

crazy charlie

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Re: Water in the bilge - past zinc bolts?

There should be a rubber washer over the threaded stud before a zinc is screwed on.The serve no strengthening purpose so just make sure there are rubber washers before the zincs go on.You may want to put a bead of silicone or 3m 5200 around the base of the stud to waterproof it.I would attempt to do the same on the inside of the transom if you can get to it.Charlie
 

Fishermark

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Re: Water in the bilge - past zinc bolts?

I went to take the zinc caps off and the entire bolt (or what's left of it) came out. :eek: Am I correct in assuming that the entire engine and y pipe needs to be pulled to get at the inside part of the remainder of these two lower bolts? (Both of them are corroded away).
 

Fishermark

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Re: Water in the bilge - past zinc bolts?

Well, I will go ahead and answer my own question in case this comes up for anyone else - Upon further investigation, yes, it does appear necessary to pull the engine and y pipe to get at these bolts. I am surprised these bolts are aluminum. I expected stainless steel. I guess there would be a problem with galvanic (is that the right word?) action with the stainless bolt and the aluminum gimbel housing.<br /><br />-- Just a note of caution to others - check your zincs not only for deterioration and wear, but also for any "coating" that may have formed on them. I believe the reason the aluminum bolts corroded away is because the zinc caps had coated up with a "corrosion" of their own with nullified their effectiveness. --
 

crazy charlie

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Re: Water in the bilge - past zinc bolts?

The acorn zincs are so cheap that they should be changed every year or at least cleaned up if they show no signs of deterioration.Sorry to hear of you big job ahead of you.Maybe you should consider 5200 the holes and bolts and add zincs somewhere else to save you a big job.Charlie
 

Fishermark

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Re: Water in the bilge - past zinc bolts?

Yes, I am "5200ing" the remainder of the bolts -- putting them back in for the time being. (They obviously haven't been holding anything for awhile). When I get some time :rolleyes: I will pull the engine and replace the bolts and do some other maintenance stuff down there. (I put this engine in myself last fall - it really isn't that big a job, just a little time consuming).
 

fireship1

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Re: Water in the bilge - past zinc bolts?

Sticking things together with 3M 5200 marine sealant. It's one of the most tenacious marine bedding compounds/sealents available. You actually need a special anti bond just to remove it. Try unbedding something that's been installed with it without using the anti bond chemical. Fun! :D
 

crazy charlie

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Re: Water in the bilge - past zinc bolts?

5200 ing is using one of the strongest sealants/caulking known to man.If you want to secure 2 things together permanently and I mean permanently,use 3m 5200 sealant.The only thing I have found that it does not adhere to well is the smoothe plastic finish on a vacuum cleaner casing and the smoothe plastic inside a refridgerator.If I scuffed the surface it would have bonded better but everything else I have put together with it is still permanent years later.Charlie
 

Peter1959628

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Oct 28, 2003
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Re: Water in the bilge - past zinc bolts?

Thank you i just have never come across this product before.<br />Sounds like it can be effective for a lot of bonding applications.<br />I will look out for this as could come in very usefull.
 

Fishermark

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Re: Water in the bilge - past zinc bolts?

Now that you know what to look for you will see that you can get it just about anywhere -- certainly anyplace that sells marine gear. Even your typical Wal Mart.
 
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