anti-seize with stainless bolts?

[robbyusa]

Re: anti-seize with stainless bolts?

I keep thinking about this <br />Why did anti-seize work so good when the definition of eloctrolosis seems to be some thing like this: <br />Two dissimilar metals separated by a electrolitic solution. <br />Graphite dose not corrode but is a very good conductor. <br />Therfor the two metals have a very good electrical connection over their entire area that dose not corode at all.<br />If you took two metals and pute them in a saltwater bath not touching each other elctrolosis would occor but if you could guarentee that they would stay at the same electrical potential by connecting them with a very good conductor that dose not corrode would that not stop the electrolosis? maybe its because its such a good conductor that it works not inspite of the fact? Is this possible?

 

[Scaaty]

Re: anti-seize with stainless bolts?

Originally posted by phatmanmike:<br /> robby, because the the anode is zince, and will corrode before any others. its sacrificial. it doesnt matter if they are stainless and aluminum or not, because their on;y job is to hold on that zinc.

That was not what I meant...it was a reply to Rabbit saying Alum and SS don't mix.. But since you bring it up, what kind of bolts would you use to hold the lower unit up? Plastic, aluminum, steel? No, stainless. Its the only one that will hold up, unless all these years I'm doing something wrong. And that includes 21 years as a Journeyman Machinist. And also thats why so many lower unit R+R bills have "Heat the bolts out". The newer motors might have some sort of inserts, but the last Force L/U I took off had the neighbors closing the drapes and locking the doors fearing for their saftey, as I was getting quite vocal. But any other bolt but SS would not work. Just a thought, and not trying to start a argument.

 

[Scaaty]

Re: anti-seize with stainless bolts?

Originally posted by robbyusa:<br /> I keep thinking about this <br />Why did anti-seize work so good when the definition of eloctrolosis

Actually its Galvanic corrosion, But I don't feel like getting into it anymore...(wheres my damn oars and something that floats...)

 

[kd6nem]

Re: anti-seize with stainless bolts?

Robby6950, <br />I stand corrected. It is galvanic corrosion unless stray currents are involved, to over simplify a bit.

 

[jim dozier]

Re: anti-seize with stainless bolts?

Bearcat you need to review your chemistry. Galvanic (Luigi Galvani) corrosion is essenitially what happens inside a wet cell battery. It occurs when 2 or more dissimlar metals or conductors (graphite) are brought into contact in an electolyte solution. One conductor becomes the anode and the other the cathode. The anode corrodes faster. In the case of graphite or copper or stainless steel in electolytic contact with aluminum, the aluminum will be the anode. In a carbon zinc flashlight battery the carbon (graphite) will be the cathode (+) terminal. The zinc will be the anode or (-) terminal and preferentially give up electrons to the cell creating an electric potential or current when the terminals are connected.

 

[18rabbit]

Re: anti-seize with stainless bolts?

Bearcat – Technically, you are correct. It is a galvanic process. The zinc (anode) and something else in the water (cathode) are the terminals. The dissolved salts/metals in the water is the electrolyte. The whole setup is effectively the same as the battery JimD mentioned.<br /><br />Electrolysis or galvanic corrosion, doesn’t matter…everyone one here knows what you are talking … and that electrolysis is really that painful process women subject themselves to for the removal of unwanted facial hair.

 

[Scaaty]

Re: anti-seize with stainless bolts?

Originally posted by 18rabbit:<br /> <br /> electrolysis is really that painful process women subject themselves to for the removal of unwanted facial hair.

And VERY similar (painful process) to removing stainless bolts from aluminum cases!

 

[robbyusa]

Re: anti-seize with stainless bolts?

From most of what I have read the bolts in my engine should have all fallen out years ago but the only problem is that they are in perfect shape.<br /> Could it be that the anti-seize works in a more complicated way than any of us understand?

 

[jdlloyd_iboat]

Re: anti-seize with stainless bolts?

I am new to boating. I have bought a well used Winner bass boat with a 1990 Evinrude 150HP V-6 crossflow motor. Thermostat housing was leaking so I decided to do some R&R. 4 cap crews 1/4 20 hold the cover. These were rusted on the cap and appeared to be grade 5 hardware (3 slashes on head). I don't think these were stainless. Anyway, 3 screws came out with difficulty but did come out-- you guessed it, the 4th twisted neatly off flush with the head. (By the way, the screws were rusted except for the part of the screw enganged into the threads of the head; is this unusual?) I have read much in this forum about removal and have decided to drill out and have started with a 7/64th drill pretty well centered. I am now soaking with a penetrant but have not applied any heat to try to break the corrosive bonds in the threaded head. I won't work on it again for a week.<br /><br />Questions -- OEM replacement screw is nearly $3 per screw. I presume high quality stainless.<br />Are these much preferable to a $1 SS screw bought at Hardware store? I presume my broken screw was cheaper SS or even carbon steel but am not sure-- it drills fairly easily. At HW store there were choices -- grade 5 and grade 8 carbon steel and the aforementioned cheaper SS. Any thoughts on using anything other than stainless steel or is this a dumb question with marine engines? (Something to be said about the ease for drilling broken bolts out!) Will grade 8 be easier to remove in several years because of its strength? Any thoughts on application of anti-seize with any of the screws that I mentioned? I saw a lot of talk about anti-seize in these forums but no firm answers. Sorry for long post but I like to make these repairs so they will last and not be a problem for the next repair job.

 

[CFronzek]

Re: anti-seize with stainless bolts?

Dunaruna,<br />The way heat is conducted away from the tip of a spark plug is thru the threads and the gasket. If you put anything on the plug threads you are raising the heat range of the plug. It may or may not effect the way the motor runs. Changing the heat rang on a dirt bike motor with 12:1 compression could be asking for trouble but on a low stress outboard it probably isn't so critical.

 

[Dunaruna]

Re: anti-seize with stainless bolts?

Thanks for the reply - 2 years and 4 months too late