Sounds basically a good plan, Mark. A couple notes for others: 1. Take some care not to breathe the fumes when you play with melting lead. I know that inhaled is much worse on the brain cells than ingested (as from kids gnawing on windowsills painted with old lead-based paint), and this sounds like it might qualify as "inhaled." I melted lead like this long ago to cast a slug for a sailboat keel, and that's been my excuse in the years since. We don't need a bunch of KR pilots lowering their IQs. (Someone with medical expertise may correct me, but I'm going to keep using this excuse anyway.) 2. I doubt that pouring epoxy in the tube before pouring the molten lead in would have held it. In your case, you could just stick a drift punch to the lead after it has cooled, thump it once or twice with a hammer, repeat at the other end. Expanding the lead like that to the form tube it should grip tight. Or, use copper tubing for your form tube -- the lead will bond to that. 3. Thinwall 4130? I know one gets in the habit of using the lightest material that will work, but this is the obvious case when heavier is not bad. If you have that thinwall around and want to use it, fine, but wouldn't a length of 1/2" iron pipe have had more texture inside and out for bonding inside to lead or outside to carbon fiber? Iron a bit less dense than lead, you might have needed a few more inches total. 'Course, the iron pipe could rust, so . . .
My choice would be copper tubing. Anything wrong with that, that I'm not seeing? Any other metal touching this? Rich Meyer Millersburg IN 46543 [email protected] -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Mark Langford My aileron counterweights are 3/4" thinwall 4130 tubing filled with lead. It was awfully easy to pick up a pile of free tire weights at the Firestone store and melt them down in an old boiler on the hot plate. Takes a few minutes to melt them, ladle off the road scum on top, and then you've got yourself some fine looking FREE lead! Poured it into the end of the tubing (one end was stuck in a coffee can full of sand) and in a few minutes I had a nice leading edge aileron weight. One thing I'd do differently is pour some epoxy in the tube first, and tilt and rotate it so that there's a little epoxy to hold it in place. Otherwise when it cools off it will contract and slide around a little in there (kinda like mine did).
