Teaching Ralf to speak won't be much use if his circuits are destroyed, so the first thing on our shopping list is a tin welder.
Unlike normal walkthroughs, in Nice Game Hints you can select just the puzzle you want hints for. Here are listed the puzzles for "A Welder to Weld With" in Unusual Findings. The guide you choose only contains information about that puzzle, reducing possible spoilers for other puzzles.