Post by sc397 on Mar 15, 2019 6:27:24 GMT -8
Getting Midwestern rusty blocks de-rusted is a ongoing problem for me. My old machinist has a pretty good hot tank that would take some of the rust off. We would still have to wire wheel it to really get it good enough for paint to stick but, it was acceptable. My new machinist just has a de-greaser which takes no rust off whatsoever. I have actually taken a block that was cleaned by the new guy to the old guy to get the rust cleaned off. Yea, it cost me twice as much as it should have to get a block cleaned. Live and learn.
So I decide that the only way to clean them good enough is take them to a chemical stripper. There are two metal stripping places with in a hour of me, one in the Detroit area and one in Toledo. The catch.. The place near Detroit charges $60.00 to clean a block but they suck. The place in Toledo charges between $350.00 to $450.00 and they look like new when they come out. Right, I am not paying $400.00 to strip a $100.00 block.
I get the bright idea to try it myself thinking that it shouldn't take much to take the $60.00 job and do minimal amount of work to get it to look like the Toledo job. Sometimes, I think too much... I have been researching the home remedies but it seems that most are removing California rust which is way different than real rust.. Anyway, I settle on the easiest way for me is the citric acid method with baking soda as a neutralizer.
First I had to figure out how much of everything I needed to submerge a 360 block in a 55 gallon plastic drum. Plopped the block in the drum and started mixing 5 gallons of hot water at a time with 4 cups of citric acid until I ran out of acid at about 30 gallons. I had to add 10 more gallons of water to completely submerge the block.
The final mixture was 10 lbs. of citric acid to 40 gallons of water.
It actually started bubbling and taking some rust off as soon as I started pouring it in. I left the block in for 24 hours and then pulled it out and scrubbed on it with a Scotch Brite pad. Blew it off as good as I could and then stuck it in the second 55 gallon drum. Dumped 4 Lbs of baking soda on the block while adding water to it. Added 2 more boxes of baking soda while hosing the water in it to mix it up as good as I could.
I ended up with 12 Lbs of Baking Soda to 40 gallons of water which probably wasn't enough.
I let it soak for about a hour in the baking Soda which was probably not long enough, pulled it out and cleaned the paste off here and there and dunked it back in to wash it off as good as I could. I pulled it off out started to blow dry it off. This took a lot more time that I thought it should. It just wouldn't get dry. Maybe I should have washed it better or used some Simple Green on it. After it was dry, I sprayed Fogging oil all over it and rubbed it in. Now, I will take it to the machinist and he will charge me again to de-grease and wash it.
Here is a picture of the block after the $60.00 strip job.
IMG_1400 by Rick Jones, on Flickr
Here is a picture after the 24 hour citric acid treatment. Better but not as good as I wanted it. I am sure it would be better after another 24 hours but how much is the question.
IMG_1403 by Rick Jones, on Flickr
IMG_1404 by Rick Jones, on Flickr
I blame it on the Experimental cast iron in the block. LOL!
IMG_1405 by Rick Jones, on Flickr
So far I have $91.00 and more time that I wanted to spend in to cleaning this block and I am not done yet. The machinist will charge me another $60.00 for his cleaning.
Next time I may skip the $60.00 job and just do it myself after I work on the mixtures and timing a little bit.
So I decide that the only way to clean them good enough is take them to a chemical stripper. There are two metal stripping places with in a hour of me, one in the Detroit area and one in Toledo. The catch.. The place near Detroit charges $60.00 to clean a block but they suck. The place in Toledo charges between $350.00 to $450.00 and they look like new when they come out. Right, I am not paying $400.00 to strip a $100.00 block.
I get the bright idea to try it myself thinking that it shouldn't take much to take the $60.00 job and do minimal amount of work to get it to look like the Toledo job. Sometimes, I think too much... I have been researching the home remedies but it seems that most are removing California rust which is way different than real rust.. Anyway, I settle on the easiest way for me is the citric acid method with baking soda as a neutralizer.
First I had to figure out how much of everything I needed to submerge a 360 block in a 55 gallon plastic drum. Plopped the block in the drum and started mixing 5 gallons of hot water at a time with 4 cups of citric acid until I ran out of acid at about 30 gallons. I had to add 10 more gallons of water to completely submerge the block.
The final mixture was 10 lbs. of citric acid to 40 gallons of water.
It actually started bubbling and taking some rust off as soon as I started pouring it in. I left the block in for 24 hours and then pulled it out and scrubbed on it with a Scotch Brite pad. Blew it off as good as I could and then stuck it in the second 55 gallon drum. Dumped 4 Lbs of baking soda on the block while adding water to it. Added 2 more boxes of baking soda while hosing the water in it to mix it up as good as I could.
I ended up with 12 Lbs of Baking Soda to 40 gallons of water which probably wasn't enough.
I let it soak for about a hour in the baking Soda which was probably not long enough, pulled it out and cleaned the paste off here and there and dunked it back in to wash it off as good as I could. I pulled it off out started to blow dry it off. This took a lot more time that I thought it should. It just wouldn't get dry. Maybe I should have washed it better or used some Simple Green on it. After it was dry, I sprayed Fogging oil all over it and rubbed it in. Now, I will take it to the machinist and he will charge me again to de-grease and wash it.
Here is a picture of the block after the $60.00 strip job.
IMG_1400 by Rick Jones, on Flickr
Here is a picture after the 24 hour citric acid treatment. Better but not as good as I wanted it. I am sure it would be better after another 24 hours but how much is the question.
IMG_1403 by Rick Jones, on Flickr
IMG_1404 by Rick Jones, on Flickr
I blame it on the Experimental cast iron in the block. LOL!
IMG_1405 by Rick Jones, on Flickr
So far I have $91.00 and more time that I wanted to spend in to cleaning this block and I am not done yet. The machinist will charge me another $60.00 for his cleaning.
Next time I may skip the $60.00 job and just do it myself after I work on the mixtures and timing a little bit.