Using 2 gallons muriatic acid and water in 55 gallon drum to dissolve rust and other 55 gallon drum with 12 pounds baking soda powder and water to neutralize acid afterwards. My cost was $10 for barrel's, $15 baking soda and my tap water.
I have about 20 gallons of it. It gets pretty expensive to fill a 55 gallon drum compared to muriatic acid. Metal prep spray from Lowe's is good too. Plus I use a strong citric powder mix on delicate metals that isn't bad to fill a 55 gallon drum with at about $25. Can get online delivered from a lab to home. Elecrolisis is another alternative method that is economical. The best thing overall is shop shot blast tumbler but isn't cheap at about $100 a block and $50 per head. I can upload a video of it. Thanks for watching.
