This is a 14′ bolt cutter that had been dropped into concrete and never cleaned that I bought at a used tool store.
I soaked the cutter in acid, disassembled it, then cleaned it with a wire brush.
I’ve very pleased with the results. I made a $5 piece of junk into a $30 cutter.
E R Haroldsen 
I remembered this article you wrote while I was recovering tools I haved found. I have since restored a nieghbor’s chainsaw that was ‘weathered’ – which is a nice way of saying uncared for or neglected, left in a shed with a leaky roof. The chain didn’t work AND was dull, rusted. The motor wouldn’t start. In about, 30 minutes, I had the whole working well enough that Trent – my youngest – had no trouble running it through an 8″ log. No acid, but an application of Kroil oil, decent gasoline, elbow grease, a little bearing grease, cleaning fluid and a tooth brush… and a light touch with my HF Chain Sharpener. I saved her – the nieghbor – at least $50-60 at the fix-it shops. Thanks – I doubt I would have even attempted it without your article.