Bismuth

[Colibri]

Has anyone tried using bismuth in weighing their cars? Have they had success?

[Stan Pope]

Has anyone tried using bismuth in weighing their cars? Have they had success?

Should be dense enough (approaches density of lead) and safe (appears to have no OSHA or NIOSH limits), but may be difficult to work due to brittleness. If acquired in small pellets, should be able to pot it into car (e.g. using epoxy). Cost appears in the range of 'acceptable', just slightly more expensive than hamburger. What's not to like about it?

But, if you ask, have I tried it? Not yet!

[ExtremePWD]

The workability is poor as Stan indicates. I don't know the typical form but if it is cheap it could be poured into a cavity. When considering the density of a material you must consider the effective density as applied to the car. Individual pellets may be dense (Bismuth is about 9.8 g/cm^3 vs Lead at 11.4 g / cm^3) but if they do not pack into a "hole" without airspace then the effective density is much less. The effective density is calculated as the total weight of the material in the hole (in this case it could be Bismuth pellets + glue) divided by the volume of the hole. In the case of lead it can be readily shaped to fit the hole and the effective density approaches the material density. This also goes for tungsten. The effective density must be considered. It will vary depending on how it is applied to a car. Square cubes in a square or rectangular cavity can approach the material density. Square cubes dumped in a round hole will have a much less effective density.

[Colibri]

Bismuth is listed higher on the Periodic scale, I.e. Lead Pb 82 and Bismuth Bi 83. I thought that Bismuth would be heavier because of this. Granted I am not a chemistry major.

[Stan Pope]

I don't know the typical form but if it is cheap it could be poured into a cavity.

When I looked up the physical properties, the melting point struck me as higher than most of us would want to deal with. I have since gone back and looked again. I found that the melting point of Bismuth is actually lower than for Lead! 521 Degrees F vs 622 Degrees F! Nice!

Had I been more alert, I'd have given a better answer first time around.

Good catch, EP!

[Jungle Jim]

I have also not used it. Only used cast bullet slugs (deformed ones of course ) weighed and melted to spec. Can't rec. that approach to anybody, but the kids always thought it was neat having "Grandpa's bullets" in their cars

[ExtremePWD]

Bullet weights probably do sound neat to the kids. I always cringe when I hear about melting lead for pinewood derby cars and avoid it due to the toxicity concerns with children. We have gone to using sheets of lead cut to size. We use ordinary precautions of washing hands after handling and avoiding sanding the lead to prevent lead dust in the air. The lead can be easily cut to size with a sabre saw by the kids.

[Stan Pope]

I have also not used it. Only used cast bullet slugs (deformed ones of course ) weighed and melted to spec. Can't rec. that approach to anybody, but the kids always thought it was neat having "Grandpa's bullets" in their cars

Kewl!

I cast "slugs" for the boys to pound into shape. Here's the mold, made from 1/4"X2"X2" angle stock. Legs are 4"X1/4" bolts and held together/aligned by short 1/4" bolt at each end.

I pick up bulk lead at the junk yard for modest cost, pour slugs in runs of 2 or 3 dozen. I do have to separate the mold sides to extract the slugs, tho.

I hope that few teams remelt, tho I'm sure that some just can't resist!

[Jungle Jim]

Bullet weights probably do sound neat to the kids. I always cringe when I hear about melting lead for pinewood derby cars and avoid it due to the toxicity concerns with children. We have gone to using sheets of lead cut to size. We use ordinary precautions of washing hands after handling and avoiding sanding the lead to prevent lead dust in the air. The lead can be easily cut to size with a sabre saw by the kids.

We all know the dangers of lead. I do not rec. melting it to anyone. My case is unique in the fact that my fathers' hobby after he retired turned into a side-business for him. And that business was as a Gunsmith. As such we were equipped to handle lead.

[Jungle Jim]

I have also not used it. Only used cast bullet slugs (deformed ones of course ) weighed and melted to spec. Can't rec. that approach to anybody, but the kids always thought it was neat having "Grandpa's bullets" in their cars

Kewl!

I cast "slugs" for the boys to pound into shape. Here's the mold, made from 1/4"X2"X2" angle stock. Legs are 4"X1/4" bolts and held together/aligned by short 1/4" bolt at each end.

I pick up bulk lead at the junk yard for modest cost, pour slugs in runs of 2 or 3 dozen. I do have to separate the mold sides to extract the slugs, tho.

I hope that few teams remelt, tho I'm sure that some just can't resist!

Is it pure lead you are getting, or a melted down "mix"? The reason I ask is you may be able to get your "lead" from a tire shop for free. They usually throw away the old wheel weights. I'm not sure if what they'd have is the type you'd want (I think tin is added and the clips are usually aluminum), or what you have to melt it with, but it might be worth looking at.

[ExtremePWD]

I haven't tried melting wheel weights but they probably are a good cheap source for weights to at least pound into shape. I have found that WalMart still sells lead weights in addition to the environmentally friendly weights (much lower density). The price is pretty cheap compared to the hobby store PWD weights. My main lead source is probably the same scrap yard that Stan goes to. I think it was about 75 cents per pound! A lot of it was alloyed but still had most of the density of pure lead. The 20lb plate I bought will probably get my 3 kids through all of their years of racing.