I decided that prepping the frame on sawhorses wasn’t going to be a good solution. I expect I will prime and paint the frame myself, so the best way to do that is to put the frame on a rotisserie. I had already built one I thought would work for the painting, so I tried it on the blasting part.
It worked pretty well, but wouldn’t let me spin the frame all the way upside down. The two hooks on the back of the frame stick back so far they were catching on the vertical post of the rotisserie. I also underestimated the weight of the frame. I can hoist it around with not much difficulty, but it put a lot of strain on the legs of the rotisserie. So much that the posts started dragging on the ground.
To fix that I put another caster right under the posts and gave the legs more support with additional bracing. I modified my eye-bolt setup to have the frame stick farther away from the posts, and that one allows the frame to spin all the way around. Problem solved.
I had been thinking I would not blast the frame completely clean because of the stubborn black paint, but I have not found a primer/paint setup that will be really good on clean metal, maybe some very minor rust, and paint. The close ones I found looked more like roofing tar than paint, and that’s not what I’m going for with this project. It probably will look cheap and won’t match the paint I hope to use for the suspension and other undercarriage parts.
So I decided to keep blasting the frame. The coal slag was not strong enough, and the garnet was too expensive, so I kept looking around. I found recycled glass media at northern tool for $9 per 50-pound sack. I bought two. That media is strong enough to cut through every layer on that frame, and seemed to work fine with the pot blaster. That may be in part because I also added a water separator, which helped quite a bit. But I ran through 100 pounds in a couple hours and am still not done with the frame. That’s kind of frustrating, but I’m assuming that a professional blaster I would have similar struggles with this project and charge me an arm and a leg to get the frame 100 percent clean. So I will buy another 100 pounds next weekend and keep inching toward a clean frame. If nothing else, it will make our driveway look event more like a beach (per Beka).
Pics of the recent work: