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Tikal48 · 08-12-2015, 08:52 PM

Chuckmc8,

On the rust removal process, I used a couple of different methods, but honestly, if I had to do it over again, I would have sent it to a blaster. This process was slow, but works best when you can submerge the parts completely. With small parts these methods are great. But these methods do little for removing any paint, and beware on fine threaded parts. The threads will be eaten away if they stay in the solution very long. I found this out on my door hinge threads. For all of the methods below, hot days are best. Doing this at temperatures below 70°F is useless.

First method I used was 1:4 mixture of vinegar and water. I had some heavily rusted parts and this took about three days, but came out like new. You need to neutralize the parts after treatment with baking soda and water. You will need to immediately dry. Alcohol works good to displace the water, or blow it off with compressed air. I also saw something on the internet of adding salt, but I did not try that. It is suppose to increase the acidity. I would not use this on cast iron.

Second method I used was phosphoric acid. I found this at Home Depot in the form of concrete "Prep and Etch", by Klean Strip. It runs about $16 per gallon. I also used about the same mix ratio. I was also spraying this on parts that were too big to submerge. Do NOT let this dry on parts overnight. Wash it down at the end of the day with water. It forms a film I would best describe like Pine rosin. It created more work to get rid of that. You can also spray the parts and cover is plastic wrap, to keep it from drying out. Otherwise, I was spraying about every 30 minutes. This works good on cast iron, because unlike vinegar or muriatic acid, this converts the rust into iron phosphate. Muriatic acid and vinegar gets into the pours and can keep eating if it is not properly neutralized. The phosphoric acid will leave a white powdery substance on the surface. You can use a wire brush to remove this before painting.

I've seen on the net about using molasses and water, but I have not tried that. Again, that requires full submergence of the parts. There is also the muriatic acid and water, which is more aggressive, but it rusts immediately after. I did this a little when I was in a hurry. But I neutralized it and washed back over it with the phosphoric acid solution to get rid of the flash surface rust.

I hope this helps!

08-12-2015, 08:52 PM	#11
Tikal48 Registered User Join Date: Jul 2015 Location: Shreveport, LA Posts: 209	Re: Harold's '48 S10 LS1 Build Chuckmc8, On the rust removal process, I used a couple of different methods, but honestly, if I had to do it over again, I would have sent it to a blaster. This process was slow, but works best when you can submerge the parts completely. With small parts these methods are great. But these methods do little for removing any paint, and beware on fine threaded parts. The threads will be eaten away if they stay in the solution very long. I found this out on my door hinge threads. For all of the methods below, hot days are best. Doing this at temperatures below 70°F is useless. First method I used was 1:4 mixture of vinegar and water. I had some heavily rusted parts and this took about three days, but came out like new. You need to neutralize the parts after treatment with baking soda and water. You will need to immediately dry. Alcohol works good to displace the water, or blow it off with compressed air. I also saw something on the internet of adding salt, but I did not try that. It is suppose to increase the acidity. I would not use this on cast iron. Second method I used was phosphoric acid. I found this at Home Depot in the form of concrete "Prep and Etch", by Klean Strip. It runs about $16 per gallon. I also used about the same mix ratio. I was also spraying this on parts that were too big to submerge. Do NOT let this dry on parts overnight. Wash it down at the end of the day with water. It forms a film I would best describe like Pine rosin. It created more work to get rid of that. You can also spray the parts and cover is plastic wrap, to keep it from drying out. Otherwise, I was spraying about every 30 minutes. This works good on cast iron, because unlike vinegar or muriatic acid, this converts the rust into iron phosphate. Muriatic acid and vinegar gets into the pours and can keep eating if it is not properly neutralized. The phosphoric acid will leave a white powdery substance on the surface. You can use a wire brush to remove this before painting. I've seen on the net about using molasses and water, but I have not tried that. Again, that requires full submergence of the parts. There is also the muriatic acid and water, which is more aggressive, but it rusts immediately after. I did this a little when I was in a hurry. But I neutralized it and washed back over it with the phosphoric acid solution to get rid of the flash surface rust. I hope this helps!