1. Go to a tire store and ask the manager for some used tire weights. Make sure you explain that they're for RC planes. Many time they are interested in aircraft and will give you MANY pounds.
2. Take a 2 X 4 and a router and route 3 - 4 parallel grooves in the surface of the 2 X 4. Mine were about 1/2" wide and 3/8" deep. This type of mold will result in long bars of lead that are easily cut, consistent in weight, and easy to epoxy about anywhere.
3. Since lead weight is most effective in the extreme nose, you can take a piece of tin foil and wrap it over the nose, remove it, pour molten lead into the "tin foil mold", and then cut off the nose of your model and glue it on in place of the wood nose. A little sanding, painting, or covering and nobody except you will nose!
4. Get a steel can (soup, fruit) and a propane torch or camp stove. Go OUTSIDE and melt the lead in the can. The dirt, oils, steel rim clips will float on the top and can be scooped off or when poured will usually stay in the can. With a vise-grips or channel lock pliers pour the lead into the mold of choice.
One lead melting session and a resulting 8-10 lead bars from the 2 X 4 will last "forever". Best of all, it's free. I also use these for weighting model RR cars and locomotives.
Enjoy,

Doug