| Author |
Message |
    
galaxiebill
New member
Username: galaxiebill
Post Number: 1
Registered: 08-2006
| | Posted on Monday, August 21, 2006 - 06:25 pm: | 
|
Hello, I have visited this site and found everything about rust on old engines useful.
I have a question. You mention graphitization of cast iron. I have a small 4.5 hp Norwegian Sleipner gas marine engine, and I see this graphitization. Is there anything I can do to stop it, or even reverse it ?
Bill Brox |
randy_ridderbush
New member
Username: randy_ridderbush
Post Number: 3
Registered: 06-2006
| | Posted on Wednesday, August 23, 2006 - 03:33 am: |
|
Bill:
In response to your first statement about rust...
Rust can removed easily with EVAPO-RUST. It cleans metal to almost new. Check it out.
Randy Ridderbush |
galaxiebill
New member
Username: galaxiebill
Post Number: 2
Registered: 08-2006
| | Posted on Thursday, August 24, 2006 - 04:09 pm: |
|
I wish someone knew the answer about graphitization....
Bill |
rbprice
Senior Member
Username: rbprice
Post Number: 217
Registered: 11-2001
| | Posted on Thursday, August 24, 2006 - 09:36 pm: |
|
Hello Bill - I'm not sure where you found the term graphitization but it is a metallurgical term referring to the conversion of iron molecules to graphite at high temperatures. It is widely used in the casting industry. See this link http://www.iupac.org/goldbook/G02691.pdf
for a formal definition of the word as used in the metal casting industry.
As for rust removal, there are dozens of references to that on this web site. Just do a search on rust removal and you will find pages of info and numerous links.
Hope this is of some help.
Bob Price |
galaxiebill
Member
Username: galaxiebill
Post Number: 6
Registered: 08-2006
| | Posted on Friday, August 25, 2006 - 07:17 am: |
|
Hello Bob,
I think you have misunderstood my question.
Here is a link, please read it. http://www.oldmarineengine.com/technical/corrosion_1.html
As you will see, graphitization is a form of corrosion that causes cast iron to get weak. This goes on at the same time the cast iron is rusting too.
My question is if there is anything to do to stop the graphitization or even better, to reverse it ?
This graphitization has nothing to do with the graphitization you mention in your link.
Bill Brox |
rbprice
Senior Member
Username: rbprice
Post Number: 218
Registered: 11-2001
| | Posted on Saturday, August 26, 2006 - 08:32 am: |
|
OK Bill - what you are concerned about is the insidious microscopic destruction of the iron due to the effects of salt water and all the subsequent chemical reactions that occur.
As the article mentions, the best solution is a highly alkiline solution but be careful, high pH solutions are dangerous to the skin and eyes.
Short of that, kerosene, which can permeate the pores of the cast iron or antifreeze which will absorb the water. But none of the above will remove the hard deposits.
I believe that the only way to really get rid of the hard deposits is to heat the engine block to 900 deg. F for several hours. That will chemically change the hard deposits to a soft almost powder like substance which is more readily removed. It may also effect the salt molecules which are the root cause of the corrosion problem.
Bottom line is that there is no simple methodology to neutralize the salt/ferrous/water process and certainly nothing to reverse it.
Bob Price |
