@HopelessDemigod @vk2tty @vk6flab Oh, and Frankenstein is kind of what I do, as long as it's solid and reliable, and does what it's supposed to do for a long time.

Speaking of long time, if you want to solder to stainless or ordinary steel, you can use hydrochloric acid (muriatic acid, pool acid) and it will work fine but won't last. the trapped chlorine atoms will react and the joint will fail in about a year. Use phosphoric acid instead.