Hi Nick and Tim,
Sorry to be so long getting to post these pictures. I'd say the pictures are self explanatory, but...
Set one. I have three pieces of Maple. Any wood will do. The harder and less grain the better. It is important that the sides that contact each other are DEAD FLAT so you don't have seepage. As the mold gets charred, you will get a little, but not bad. You can replace just the outside pieces at least once once they start getting leaky.
Cut the one in the center to the shape you want. I used the two little skinny ends to drill and countersink holes into to attach it to the decoy. This mold is 1/2" wide. Simply line up the tops and clamp them together, fill with molten lead and allow to cool twice as long as you think you need to and open. I get about 25% that need to go back in the melter.
Mold number 2, teardrop. Carved out of a piece of Jarrah and left a hole to pour the lead through. The piece that claps to the other side is not shown but just a flat piece of wood. I do this instead of pouring into the open mold so the back is flat and even. The larger hole on the top someone told me is called a head space, but I'll take their word for it. Maybe that's wrong. I'm going to make it bigger on the next one. Seems the weight of the lead on the outside of the mold helps it to fill more evenly. Same deal, clamp together, pour, let cool, open repeat. I put a hole in the weight afterward and attach with a no 8 brass screw. I'd say this mold has made 50 weights. It's got another 50 in it still.
Last, sorry for the blurry picture. a piece of 3/32 lead sheet from a hospital x ray room cut to shape and the edges peened smooth. Pilot holes punched with an awl or nail, and attached with 7/8" copper tacks. I like this best for round bottom decoys. Especially if they are light, it don't take much to self right them. this piece is around 2 1/2" x 3 1/2" and self rights real nice. The decoy is white cedar and the walls hollowed out to less than 1/2" so its pretty light.
A few things to consider.
Lead weighs just over 6 1/2 ounces per cubic inch. Plan accordingly while making a mold.
Lead can be dangerous. Excersize caution.
I found that I have more success pouring at lower temps. My melting pot has a scale from 1-10. I run it around 5 and it works fine. Prolongs mold life, and takes less tiome to cool. I turn it hotter for bigger stuff.
While a bit pricier, lead shot is an excellent medium, especially if you are pouring small numbers of weights. A ladel held over a propane torch and pour it in slowly will melt quick.
An old plumbers cast iron ladle can be had for under 10 bucks at an antique store. They hold heat better than a kitchen type one, are safer, and give you more work time.
Don't try to drill all the way through lead. I tried it on my drill bress on a 2 pound lead disk for weighting a super duper mag OS and the bit caught in the lead spinning it free from my hand before breaking off the biot and throwing it across the shop with enough force to put a DEEP dent in the OSB wall. Drill ONLY with a hand drill, at slow speed and finish the whole by punching through with a nail.
Don't touch your mouth or eat until you've washed you hands good.
Hopefully this helps. Good Luck,
paully
