Would it be safe to remove the built up rust on wheels' control arms by soaking them in vinegar?
Or is Hydrogen embrittlement a concern for a run-of-the-mill, 10-years old control arm, which is (I think) made of cast iron? And one should better stick to a wire brush.
You will get better results derusting with phosphoric acid instead. You can buy it in bottles ready-to-use as concrete prep or concrete etch in hardware supply stores, which is used to prepare broken concrete surfaces for patching.
I have derusted large thread-cutting taps this way, with no embrittlement. It also mildly undercuts the thread teeth, leaving them sharp enough to cut skin. In fact, you can resharpen dull files with an overnight soak in concrete prep.
