rust in radiator inlet/outlet

[aqh]

I have an old radiator that uses cast iron inlet and outlet pipes to the radiator. I discovered much internal rust flaking in these areas. Is there any repair method to stop this rust? These pipes are not leaking now but may erode away creating a costly repair. Thanks in advance for any reply.<P>------------------<BR>arnold.hager@fnc.fujitsu.com

[Guest]

Having had some experince with steam boilers what you are describing occurs when you use tap water instead of distilled in your radiator. Oxygen will cause the rust and pitting on cast iron. Now there are a couple of things to do, but I caution since you are dealing with older material. Citric acid will remove the rust, but you don't know how good the material underneath is. This can be dangerous to the metal. <P>The second method of cleaning on a boiler (similar to a car radiator) is using about 1 cup of TSP (Tri sodium phosphate) available at any hardware store dissolved into 1 gallon of water. In your case, drain off about 1 gallon of water and fill up with this solution. Run the car up to normal temperature and then dump the water. Allow to cool and refill with water, run again to normal temp and then flush. You may have to do this about 3 or 4 times until the water comes out clean. TSP removes the oil, dirt and corrosion from the inside without being harsh. If it can be used on cast iron boilers with brass and steel fittings, it should be safe on a car.<P>I would suggest then refilling with whatever you are using for a rust inhibitor (coolant?) mixed with DISTILLED water only. <P>Any other thoughts out there?

[Guest]

Hi all !<P>The mixture of TSP and water generates a phosphoric acid solution, that is a good rust remover.<P>Once I used in my 1951 Plymouth radiator a solution made of one quantity of kerosene to four quantities of water and run the engine for a while. I changed the radiator filling for 3 times and at the end the water was very clean. However,in the last time the radiator started to leak and I have to weld it, but final result was good, because the cooling improved. <P>So my conclusion is: any kind of rust cleaning solution you use can create leaking, because it depends of the level of rust the radiator has and the power of the solution you using . <P>Unfortunatly I think there is no miracle to solve rust problems of an old radiator. If someone knows a way to clean the radiator without the risk of creating leaking I would like to know.<P>Other thoughts ??<P>Regards,<BR>Julio Albernaz<p>[This message has been edited by Julio Albernaz (edited 08-28-2000).]