Here is another suggestion about less expensive weights. While free tire weights are cheap, the density remains at around 9gms/cc (Nine times the density of water). Tungsten is over 16 which is why in certain circumstances it is desireable in spite of its much higher cost.
For people looking for a cheap, very dense alternative; I have a suggestion....
Find a tool sharpening shop and ask for broken pieces of Tungsten Carbide. TC is the work horse of machine shops for a cutting material as it is approaching diamonds for its hardness. It is very brittle, and the hardness precludes any sawing, machining or forming; but the brittleness property is usefull for my purposes. Shatter a bunch of the TC and use the pieces to fill in the areas you wish to weigh. The specific density is less than pure Tungsten, but at 14g/cc it is still WAY heavier than lead. I made a slurry of molten lead with lots of broken fine chips of TC to fill a brass N scale Jawn Henry locomotive body decades ago. That N scale loco weighed one and a half pounds. The lead helped, but the TC was the material which tested the strength of the bridges the engine traversed!
