Monday, September 24, 2012

Casting Lead - An Experiment

As noted a couple of days ago, I bought enough lead for the CB weight and a spar measuring weight (10kg weight used to measure the stiffness of yards and booms). Doryman suggested making a lead-line - which is an excellent idea for a small boat intended for exploring unknown (to me) areas.

I found a website describing how one guy made a lead-line. He wrapped a shape with aluminum foil, supported the shape with sand inside a can, removed the solid shape, melted and poured lead. That's the short version. Here's the link to his post:

http://www.jonnymooresailing.co.uk/leadline

Using a small (1.5" diameter plastic bottle about 6" tall) bottle for the shape, I wrapped it in foil (double layer of heavy duty aluminum foil), set it in a large enough can, filled the can (around the shape) with sand and removed the plastic bottle to create my mold. So far so good…

The two-burner propane camp stove was set up outside and a used, heavy-duty pot (from Good Will) was large enough to hold one of the 13.5 lb. pigs of lead. So far so good…


And then things didn't go so well… An hour of heating did nothing… heck, the pig was barely warm to the touch… I turned off the stove to think about this…

Back at it, I relit the stove, turned the heat on Full-Blast HIGH… and waited… 20 minutes later - nothing. I cut a small chunk off another pig and put it in the pot - and watched it melt within seconds! I started thinking about cutting the pigs into small pieces to facilitate melting when I realized the lead in the pot was just about completely molten… 35 minutes of Full-Blast HIGH heat did the trick (why didn't I think of that sooner?).

After spooning a few bits and pieces of non-lead debris from the surface, I poured the lead into my mold. All went well… All I had to do was wait for the lead to cool which it eventually did… Pulling the mold from the sand and unwrapping (what I could) the foil left me with this:


It is an incredibly rough casting which weighs about 3 lb. It is about the right size but much too rough to work into a final, usable lead-line. The really nice characteristic of lead? It can be remelted and recast. I will work on my foil wrapping and mold making.

It is fun experimenting like this with a simple project (easy shape and not too much lead involved) to learn what I need to learn to cast the CB and spar weights - and a lead-line).

2 comments:

  1. From here that looks like a burrito wrapped in foil but I'll take your word for it. ;-)

    ReplyDelete
  2. ...which is exactly why it will be melted down and recast! :)

    ReplyDelete