Rendered just over 300 lbs of wheelweight ingots last night and have a few observations:
- this is "Spring Tire Season". Better hit the tire shops in the next two weeks. I'm taking the Jimmy in for spring servicing next week and I will have a recycling bin ready in the back.
- I had acquired about 400 lbs of "raw" wheelweights from three locations. Two accepted my offer of $20 per 5 gal, another insisted I just take it away no charge. The two that accepted the cash had "another guy" who also dropped by and paid, the one that was free also had a guy coming but for free. Two other places had either a contract or an agreement with someone else, so I lost out. 2+ years ago you'd run into places where they had piles they didn't know what to do with - not now. Metal prices are rising and I am stockpiling. I don't mind paying $20 for what ends up as about 150 lbs of ingots.
- "cleanest" lot of wheelweights I've ever smelted. Bone dry, very few rubber nipples, paper etc. (no brake calipers!).
- however, by far the most zinc, and stick-on weights I've ever seen. Also the most large wheelweights. The large and stick-on could be explained by where I got them (one truck place and another that does lots of mag wheels). The zinc just seems to be the way it's going.
- avoiding zinc is too easy. My mix is never more than about 50 degrees over the melting temp for lead (I have a thermometer), so it's well below the meting point of zinc. If you ladle immediately after the fresh batch of added raw wheelweights have separated from the metal, i.e. just after it goes from "slurry" to smooth, the zinc will be floating intact along with the rest of the waste.
- I am always low on pure lead, so I look forward to the stick-on weights which are just that. I separate them to reclaim the pure lead, but also to avoid diluting the antimony and tin in the wheelweight ingots. This batch was problematic - lots of smelly adhesive, and difficult to melt. I'm not altogether sure that they were all pure lead, some floated untouched, so I discarded them. I suspect they might be stick-on zinc. I have segregated the pure lead ingots from last night and will test them for hardness to see if they have the hardness (~BHN 7) of pure lead. When working with reclaimed alloys, you're never sure what you're getting, but the hardness is a good indicator (if ~BHN 7, then pure, or close to pure lead, if ~ BHN 12, then "classic" wheelweights, e.g. lead plus a few points of antimony and some tin) - so far so good.
That's all for now.