On September 21, 2013 Ron Dignard in Chesterville, Ontario, Canada wrote:
I just wanted to share with everyone my experience on removing rust from hardware on my MGA project car. I purchased a rock tumbler (twin drum) from Harbor freight and 5-lbs of abrasive. I also purchased a gallon jug of Evapo-rust to use as a lubricant. I was thinking of just using WD40 as the lubricant but after seeing this stuff called Evapo-rust I thought I would give it a try since it was environment friendly. I placed the bolts, nuts and washers into the drums, added the abrasive and lubricant, let it run for about two hours.
The result was amazing, most of the bolts came out looking like new. After taking the hardware out of the drums I rinsed them off with water, dried them and then gave them a quick spray of WD40 to prevent flash rust. This is a simple and effective way to clean up old rusted bolts.