Reply to 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.
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)