3D print

What I am waiting for is somebody to 3d print tungsten powder infused resin flat car/gon decks/floors so that open top cars can be properly weighted.

Diameter

What diameter is the shot?

Shot size

#10 is 1.78 mm; #9.5 is 1.91.

i found 5 pounds of  #9.5 for $220 ($2.77/ounce).

For those used to imperial measurements

For those used to Imperial measurements (inches):

#10 shot = 1.78mm or 0.07" --- just a hair larger than 1/16" ...

#9.5 shot = 1.91mm or 0.075", which is right at 5/64" ...

Tungsten infused resin

Neat idea but that would mean mixing tungsten powder into the liquid resin. The tungsten might re-direct the laser light that hardens the resin — or maybe it wouldn't be a problem. However, it would be very expensive to have a vat of tungsten infused liquid resin just to have a relatively small amount of it that becomes the final part.

I like the way you think. I hope that someone could figure out how to make it possible.

For the flat car deck, how about

smearing a paste onto a pre-cut piece of fiberglass screen?  Once it hardened, you'd have a sheet you could then sandwich between the wood deck and the frame.  Not ideal, but hey, would work.

Blair

Thin weight

One could always mix tungsten powder with resin and put it in a very thin flat mold and make thin tungsten infused resin castings, the weight dependent on the mix of tungsten in the resin and the thickness.

The other option would be to put tungsten/resin in between the underframe parts. But with a cast resin underframe the spaces are pretty shallow.

Normally for homemade cast resin gondola cars I put in a 1/8" sheet lead floor that I scribe every 8" or so to make it look like a wood floor.  For About $20-25 I can get lead  vent pipe flashing  that can weight 20 or more  cars easily, so that's about $1 a car or less for weight.  The tungsten route is about $15 a car.  The question is, is it worth 15x the cost and is it significantly thinner than the 1/8" lead (allowing for a scribed styrene deck to cover the tungsten)?

Still mulling it over.

3D printing and alternatives

The only realistic 3D printing option I can find is using tungsten-infused PLA filament.  The densest stuff I can find online is 7.8g/cc and it's $559 per kilogram: Rapid 3DShield Tungsten Filament.

It's only as dense as steel, but it IS denser than other metal-infused 3D filaments.  As other's have mentioned, tungsten shot is not cheap either.  I've got goose loads for my Dad's 10 gauge and you better believe I only load them when a flock of big Canadian geese glide in.

So it's only realistic in the sense that if you can afford a coke habit, then tungsten filament is possible.

One alternative that no one has mentioned yet in this thread is Bismuth shot.  It's a non-toxic shot typically combined with 4-8% of zinc to give it a lead-like projectile characteristics.  Bismuth is 85% as dense as lead and can be worked in a similar fashion with a melting point of 520*F, lower than pure lead!  You can melt the stuff in a campfire.  Most importantly, Bismuth is cheap.  A 1lb bag of bismuth shot is $12-20.

Interesting!

Never thought I’d see the day that MRH hobbyist went Hobby Supplies dealership, but, then again, why not!  If it keeps MRH in business and benefits the hobby, why complain?  Thanks for the thoughtfulness!  We really appreciate your kind contribution to the hobby!

  "The tungsten route is

I don't think any weight that multiplies the cost per car by 15 times is worth the price. Especially since flat cars can track decently  without much weight......DaveB

More nuanced than that

That's not the way to ask the question. It's a lot more nuanced than that.

Stick-on lead weights cost about $1 per ounce. Tungsten shot + tungsten powder costs about $5 per ounce. So it's not 15x, it's 5x when comparing to lead.

Second how much space do you have for weight in the underside of the car, and how much lighter is it?

If it's just 1 oz too light and there's not much good space to add weight, then being able to ad an ounce for $5 verus $1 is a good investment.

And note my terminology -- an investment. Cars that run well add a lot of joy to the layout, cars that don't run well are a total pain.

If you do need to add 3 oz to the car underside with the tungsten solution, is it worth investing $15 in that car? If not and it keeps giving problems, then ban it from the layout.