What would you use to get corrosion out of the Block?

[FoolOfAFisherman]

Got a '73 115 mercury thunderbolt that's been in saltwater. There's a lot of corrosion inside the waterjacket. I have the block off replacing the piston rings and I need to hone the bores. Before I do, I'd like to get rid of that corrosion. Can you like fill a trash can up and let it soak or something to clean the powerhead good?

 

[FoolOfAFisherman]

Re: What would you use to get corrosion out of the Block?

Has anyone used Saltaway or CLR for this process. I've read CLR isn't the best thing to use. I wonder about a gallon of vinegar mixed with about 5 gallons of water? Anyone have suggestions?

 

[Chris1956]

Re: What would you use to get corrosion out of the Block?

Be careful as you do not want the cylinders to rust. no more than a few minutes in the solution, and oil them immediately upon removal. If you have the water jacket covers off, and didn't break all the all the bolts, it is a miracle. Can you scrape most of it out?

 

[FoolOfAFisherman]

Re: What would you use to get corrosion out of the Block?

lol, well....let's just put it this way...it's not a miracle. However, I didn't break them all....just eight Working on getting the rest out. Gonna try and weld a washer onto the stud, then weld a nut to the washer. Had to pull the covers to see why I had no compression in cyl 3. Believe me, I wouldn't pull them if I didn't have a good reason. I can understand being careful with CLR but can't you be a little more generous with the saltaway?