Rust removal

[Manx Kat]

I was reading a lot on the old forums (lots of good info.) I noticed several questions about rust removal. Some people went as far as cutting fuel tanks to pieces to clean out rust and then weld them back together. I learned from a guy who made a living for many years restoring old cars and tractors for customers how to do this. Just put on phosphoric acid on the rusted part or better yet submerge the peice in it. I saw him put a whole 6 cylinder block in a tank of this acid and he said in a few hours it would come out clean. This block was coated with thick rust inside and out.
This stuff is not even toxic I am not sure where to get large quantities he had a tank with about 80 gallons, we use it all the time for cleaning lime scale of house taps. It is available from any supplier of dairy farm products it is used to clean the pipelines in dairy barns that the milk comes to the tank through. They call it milk scale remover.
Another remedy for cleaning up BAD rust and old paint this same man told me about and I have used very successfully is caustic soda also known as lye or
sodium hydoxide mixed in water. This is more toxic and must be used more carefully you MUST add the powder to the water NOT the water to the powder because of the heat caused. About a cup to 10 gallons of water and soak your peice in it till it comes clean then wash (I pressure wash ) and dry.
I find it simpler than sand blasting. If you doubt this I suggest you try on a peice of junk I am sure it will work for you as it has for me.

D.K. in S.K.

[Al Letts]

There is another newsgroup that I know many on here are familiar with and belong to. It's welding and fabrication based. Address is WWW.SHOPFLOORTALK.com . There have been many threads over the past year or so on this subject. A recent good one to read about is the baking soda based solution with a transformer based electrolysis process. One Fellow recently submerged a utility trailer chassis in a homemade polysheeted container. The process worked beautifully taking all remaining paint and rust down to clean metal. I plan on using the same mix for some of my CAT sheetmetal parts to prep for repaint.

You can do a search in the archives to bring up the thread.

HIH
Alan

[Manx Kat]

There are no doubt many good options. The one you mention sounds interesting I will look it up.
I think the caustic soda one might come in handy on say a manifold that has been stuffed with organic matter like grass by mice or something as can happen and then rusting. The caustic soda would eat up the organic stuff without hurting the metal. This is why I posted this since the thread I was reading was about a plugged manifold and he was afraid of breaking it trying to get the stuff out not even sure what all was in it.

D.K. in S.K.

[Soapy]

Manx Kat, and Al,
You can obtain the acid at your local grocery store. Lime Away is the product name. If you need it in larger quantities, try an industrial chemical supplier, or a wholesale grocery that caters to the food service industry.
Out here on the left coast, we have Smart and Final, a instutional grocer, and they carry acid, they call it Lime Gone. It is used for cleaning the lime scale from steam tables, and commercial dishwashers.

Ed (chemical salesman)

[Art From De Leon]

I have used vinegar (acetic acid), to remove light coatings of surface rust. I have a JD 10P (plastic) lawn cart that is watertight, and the vinegar is cheap enough that you can completely cover the items you are trying to de-rust.
Afterwards, rinse with water, dry, and give the part a wipedown with oil.