Pinewood Freak

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Efficient weighting with tungsten powder

January 19th, 2006 · 10 Comments

Those pinewood weights you buy at the craft store aren’t lead and aren’t very dense. Lead is nearly twice as heavy as that stuff. Don’t use it if you want to win.

Usually I melt lead bird shot into holes drilled in the car body. It’s an efficient way of weighting the car, but this year I tried tungsten beads. Tungsten more than one and a half times the weight of lead, and I was able to pack a lot of weight into a small area in the car body. But the problem with tungsten beads is that there’s a lot of wasted space in the car body.

Lead melts at about 600 degrees, a temperature you can reach with a propane torch. But tungsten melts at 6000 degrees, so melting it into the car body isn’t an option. Instead I had to pack the beads in, shaking the car to get the beads to settle.

Next year, I’ll be using tungsten powder instead. Just drill a hole, pour in the powder, and seal the hole back up. I’ll get all the efficiency of tungsten, but without the wasted space, allowing me to pack weight into a much smaller space. And it will be easier than trying to fit the beads into the car and easier than melting lead.

Comments

10 comments so far ↓

  • Tina // May 29, 2006 at 10:09 am

    Where is the best position for the weight?

  • Ron T // Oct 22, 2006 at 6:48 am

    Get a msds sheet and check tungstein powder I am sure if spilled out of car due to dropping of car it is considered hazerdious use solid tungstein and it is not hazardious.

  • Scott // Feb 14, 2007 at 10:31 am

    I’m a chemist. Tungsten isn’t hazardous. Especially if you don’t eat it.

  • Gary // Dec 21, 2007 at 8:11 pm

    Tungsten Powder is not Hazerdous but solid Tungsten is actually more dense. There is a new Tungsten Disc out (See Maximum Velocity.com) that condenses 3.25 oz of weight into a 1″ diameter and about 3/8″ tall. I tried it, easy to install, just drill a hole and drop it in. I haven’t seen anything that allows you to condense the weight any tighter and keeps it extremely low!

  • Hypertech Pine // Feb 12, 2009 at 9:18 am

    Melting lead is the really hazardous thing here. Lead in vapor form from melting WILL cause acute lead poisoning exposure and contaminate the entire area. NEVER MELT LEAD ESPECIALLY INSIDE YOUR HOME! That would lead to chronic exposure from repeated exposure from the contaminated surfaces. Normal vacuuming would only make it airborne again.
    DONT MELT LEAD to weigh your cars. Keep it in solid form and enclose it or cover it so little hands cant touch it directly. Always wash your hand immediately after handling it. Never sand lead either!
    Lead exposure is limited to ingestion and inhalation hazards and cannot be absorbed through the skin.
    With proper care it CAN be handled safely and is 5 times less expensive per oz. then titanium and is dense enough to use in this application

  • Kelly Root // Mar 31, 2009 at 10:04 am

    Go to your closest Welding Supply distributor and get 5/32 X 6 ” tungsten Rods (tig torch) drill holes in the side breal and place the tungsten rods where ever you wish.

  • Michael Blue // Jan 28, 2010 at 12:54 pm

    Tungsten putty, problem solved. :)

  • Kevin // Jan 14, 2011 at 8:35 am

    Tungsten powder has about the same density as solid lead. The powder has the same wasted space problem as the beads. Imagine zooming in until you can see each bit of powder. The ratio of wasted space per volume of tungsten is dependent on the shape, not the size.

    Instead, tungsten weights come in cylinders from 1/16 to 3 oz, and are relatively inexpensive. Lots of weight, no wasted space.

    Next time I’m going to get my hands on some osmium :)

  • D. Shawn Racing // Feb 16, 2011 at 11:38 am

    We had a solid high density 4.15 Tungsten Cylindar with some lightened wheels this year. It was awesome and fast. You have to be good at shaping the wood and have a quality scale, but if you get the COG right and do alignment, these are tough to beat at the lower racing levels. (pack, district) SO much better than melting down lead which is what my DAD used to do!

  • Bill Klingler // Jun 8, 2013 at 3:34 am

    I would like to recommend 1/4″ tungsten cubes. Put two rows of 6 behind the rear axle slot and two rows of 6 in front of the rear axle slot. Set your COM at 5/8″ to 3/4″ in front of the rear axle slot. Cut your car so it will be in the shape of a Hershey bar and keep removing wood so it weighs no more then 1/2 ounce to start. Your entire car will be no thicker than 1/4″. If speed is your only concern this set-up should be the ultimate.

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