Packard Forum Index » General

The old product for cleaning out engines and rads is no longer available. It was composed of equal amounts of oxalic acid and soda. I keep reading that the old kit contained baking soda. I find this hard to believe. I believe it is actually washing soda. I posted this for our resident chemist to respond. I am going to use oxalic acid to clean the engine and rad in the near future. I do need to verify that washing soda is the other half of the concoction. Am I correct?

All you need is something alkaline to neutralize any residual oxalyic acid and be otherwise harmless to the materials of construction. Either sodium bicarbonate(baking soda) or sodium carbonate (sal soda or washing soda) would do just fine. If you're really in doubt about the efficiency of the neutralization or whether you might have used an excess of sodium carbonate or bicarbonate, a simple litmus paper test of the last rise water is all you need but that's probably overkill, a couple of water flushes after the bicarb or carbonate should be more than adequate.