Sand blasting, esp. soda blasting. You can start with cheap equipment and work u...

		t-h-e-chief on Nov 20, 2019 \| parent \| context \| favorite \| on: Ask HN: What's the most valuable thing you can lea... Sand blasting, esp. soda blasting. You can start with cheap equipment and work up from there. If I had to start from scratch, this would be it.