Salt Water Crud - Frozen Gearshift Rod

umblecumbuz

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Re: Salt Water Crud - Frozen Gearshift Rod

... or go to the Serif website, and download their freebie PagePlus or PhotoPlus. Either program will do the same thing, (but nowhere near as good a program as Adobe Photoshop or Jasc PaintShopPro).<br /><br /> http://www.serif.com/ <br /><br />Ciao
 

jim dozier

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Re: Salt Water Crud - Frozen Gearshift Rod

Glad to see you got it unstuck. As some alluded to above the "white" deposits are more complicated than just salt. Salt water has more than just NaCL (table salt) in it. There are a number of ionic species such as carbonates and sulfates dissolved in it, each with their own peculiar chemical properties. In addition, it is also alkaline (opposite of acid). Aluminum metal will dissolve in both acidic and alkaline solutions :eek: Most of the corrosion (white stuff) is actually precipitates that have reacted with the aluminum and salt water, aluminum oxides and hydroxides and aluminum carbonates, which are relatively insoluble in water at room temperature. They are also hard. This is why they are hard to remove. Anything aggressive enough to remove them such as acid tends to remove the aluminum more than the white stuff. And as Solittle has found, the white stuff has actually formed from the aluminum and when mechanically removed leaves a crater or hole in the aluminum from which it formed. Dissimilar metals such as stainless steel just speed up the process with aluminum acting as the sacrificial anode. Cost of doing business in salt water. :(
 

umblecumbuz

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Re: Salt Water Crud - Frozen Gearshift Rod

jimd said:
[bold]Dissimilar metals such as stainless steel just speed up the process with aluminum acting as the sacrificial anode.[/bold]
This will only happen if the correct zincs are missing or not properly maintained. Just shows how important it is to fit, maintain and replace those zincs regularly, with the right zinc/alloy mix for the water you run in. <br /><br />Clean them often (file if necessary), replace when they are half worn (smaller area gives smaller protection) and make sure they make good contact with clean metal. <br /><br />Every separate piece of immersed metal needs its own zinc, or needs wiring in to the zinc-protected circuit.<br /><br />Trim tabs are specially vulnerable, because they're often out on their own. Fit an anode to each tab. If your tabs have nylon ball and socket joints connecting the actuator at each end, then the actuator itself is not protected.
 

Solittle

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Re: Salt Water Crud - Frozen Gearshift Rod

stillfishing - I don't think zincs were part of the equation on my motor. It is manual start and was not stored in the water. However the crud formed it was just as jimd has described. It formed beacuse the drain hole got plugged. I had to drill much of it out as some of it would not come off by scraping with a long screwdriver. There is some still there that I can't get to.<br /><br />I can tell you that when I get this back in service I plan to hit the drain hole with compressed air from time to time.
 

redmopar

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Re: Salt Water Crud - Frozen Gearshift Rod

Anything aggressive enough to remove them such as acid tends to remove the aluminum more than the white stuff.
I was shown this trick by a friend, and it may get some laughs and a few negative comments. So far I have only tried it on newer batches of saltwater corrosion on my electronics. Coke and pepsi have decent amounts of phosphoric acid in them(check the ingredients if you want). He showed me pouring it on the affected area and letting it sit a few minutes gets it off and and a few treatments loosens the real stubborn stuff. Not tried it on aluminum, but I imagine it would still work. I was able to take the ball of corrosion that was buldging out of the receptacle off of my troll motor plug with my fingernail after a couple of treatments. Left some nice n' shiny copper. Sanding took off the little bit that was left directly on the contacts. I was amazed, but now I think twice before I drink the stuff. Imagine what that does to your insides. :eek:
 

umblecumbuz

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Re: Salt Water Crud - Frozen Gearshift Rod

... THAT'S why I see these guys with coke bottles tied to their transoms!<br /><br />This forum is a real learning curve!<br /><br />Seriously, I've got a thing about zincs. If you have any unprotected 'noble' metal - such as stainless swim ladders or trim tabs - it's often not those bits that get hit, but they speed up the corrosion of less noble parts, like legs and aluminium props.<br /><br />Either wire them in so that they become part of the protected circuit (impractical!) or fit zincs to each isolated 'noble' immersed component.<br /><br />It also needs saying that, if a drain hole is blocked like Solittle's above, then even out of the water and sitting on your driveway, as long as the crud inside is damp, electrolytic action will continue, and corrosion of unprotected bits will keep going - such as the insides of an alloy (composite metal) leg.<br /><br />It is REAL insurance to fresh-water flush and spend a few minutes with a bent clearing wire after every trip.<br /><br />Belt and braces ... every time.
 

jim dozier

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Re: Salt Water Crud - Frozen Gearshift Rod

Acid, whether its phospohoric in Coca-Cola or Muriatic acid (hydrochloric) from Home Depot will dissolve the many types of corrosion precipitates. However, as I said above the problem with aluminum corrosion is that the aluminum itself is about as soluble in acid as the corrosion is an you end up dissolving the aluminum. This is particularly a problem on machined surfaces where you don't want pitting. It is less of a problem on some large chunk of aluminum metal. But the corrosion is usually found in bolt holes near important machined surfaces and you need to be really careful with anything acidic in those areas. :eek:
 

the machinist

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Re: Salt Water Crud - Frozen Gearshift Rod

That drain hole in the forward recess hole was changed by OMC from the original 1974 size of about 1/8" to 1/4" on the later engines at least at 1992
 

steviecops

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Re: Salt Water Crud - Frozen Gearshift Rod

I think I remember reading on here somewhere that tea tree oil helps with the corrosion. I haven't tried it. Has anyone ever used this?
 

Paul Moir

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Re: Salt Water Crud - Frozen Gearshift Rod

Thanks jimd - very informative!<br /><br />(I've never heard of a tea tree before... :confused: )<br /><br />PS - I've seen a couple lower units where the weep hole clogged and then had the puddle left in the bottom freeze and actually break out a chunk of the lower unit. Is that a possible initial cause for that hole?
 

Dunaruna

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Re: Salt Water Crud - Frozen Gearshift Rod

Tea tree oil (from a tea tree :p ) is one of those handy all round remedys supplied free of charge from mother nature. Do a google - you'll be amazed.<br /><br />Aldo
 

Paul Moir

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Re: Salt Water Crud - Frozen Gearshift Rod

Oh, ok thanks! Must be like Vegemite then eh?<br />(Heard that one a million times yet?)
 

Dunaruna

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Re: Salt Water Crud - Frozen Gearshift Rod

You'd be surprised how many aussies HATE vegemite, including me. But it is good for ya.<br /><br />Aldo
 

Solittle

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Re: Salt Water Crud - Frozen Gearshift Rod

Paul - When I started this thread I left that part out and did not take a picture of it. on the opposite side of the drain hole cavity and about 2" above it there is a small section of the casting that is pushed out from the inside due to crystalized crud I guess. It is about 1" long and the shape of the end of a popsicle stick. It protrudes about 1/16" but is not all the way through. I have not done anything with it and may not.<br /><br />This condition is not due to freezing as this is a Florida motor.<br /><br />I now have the gear shift rod free and it seems to shift OK. I tried to start it this weekend but no go. Next step is to clean the carb. I have spark and compression is 98 & 102 so I have hope. I have not had a lot of time to work on it but am in no hurry.
 
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