Tungsten Bullet Fishing Weights

[kjhambrick]

Woo Hoo !

Lookie Here !!

Maybe this would be useful for someone else ...

I am building a rocket that needs about 20 grams of nose weight.

These tungsten fishing weights look interesting and they're already shaped like a nose cone

AMAZON > Tungsten Bullet Fishing Weights

I like this page because of the table of weights and sizes ( bottom left image ),

But I'll buy them from Mr Jenson ( Jenson's Fishing Tackle in Austin ) because the girls like to visit his store to look at the 'minners' and gold fish in the aquariums.

-- kjh

 

[Rocket-Fan]

Yup, tungsten is roughly twice as heavy as brass so one could achieve the same weight is a smaller volume of space. Or twice the weight in the same amount of space. I've been using tungsten weights for years for fishing. 'Specially comes in handy on the flats in Belize, casting into a stiff wind

 

[Daddyisabar]

Powdered Tungsten for golf clubs is the secret behind my Dornier 217 N night fighter. Tungsten nose weight rocks! Lots of mass in small places. Pack it all into a Baby Bertha nose cone to get model rocket levels of stability margin.

 

[SolarYellow]

You can also get tungsten powder at golf shops, I've read. Then you can mix it with epoxy and pour/squish it into whatever cavity you want it to fill and it self-conforms and is automatically attached.

 

[Daddyisabar]

You can also get tungsten powder at golf shops, I've read. Then you can mix it with epoxy and pour/squish it into whatever cavity you want it to fill and it self-conforms and is automatically attached.

You can also pour it in straight and cap it. Thus making it reusable.

 

[cwbullet]

I just use my go to which is LEAD. As long as you don’t eat it, you will be fine.

Tungsten is interesting.

 

[mjennings]

Haven't used it in rockets, but Tungsten is the way to go for Pine Wood Derby weights. Not cheap got them in the 40% coupon days at HL.

 

[kjhambrick]

Haven't used it in rockets, but Tungsten is the way to go for Pine Wood Derby weights. Not cheap got them in the 40% coupon days at HL.

Yes, I looked at Hobby Lobby too.

This looks interesting: Hobby Lobby > Derby Car Supply Tungsten Putty Weight

28.35 grams of Tungsten Putty for $5.99 might be a good way to go.

I dunno ... I need to hold it in my hand and squish it about

I still want to look at Mr Jenson's Tungsten Bullet Fishing Weights ... the axial hole thru the center might be handy for attaching them someplace 'strategic'.

-- kjh

 

[mjennings]

Yes, I looked at Hobby Lobby too.

This looks interesting: Hobby Lobby > Derby Car Supply Tungsten Putty Weight

28.35 grams of Tungsten Putty for $5.99 might be a good way to go.

I dunno ... I need to hold it in my hand and squish it about

I still want to look at Mr Jenson's Tungsten Bullet Fishing Weights ... the axial hole thru the center might be handy for attaching them someplace 'strategic'.

-- kjh

The putty is going to be less dense. This is what we used, and looks to be less than I remembered. ($20 ish stands out). Plus if I remember might they are sized for 27/64 drill bit clearance too.
https://www.hobbylobby.com/crafts-h...6239?queryId=2be8bea1fa2248513ee0b1262b82dbb6

 

[SolarYellow]

Haven't used it in rockets, but Tungsten is the way to go for Pine Wood Derby weights. Not cheap got them in the 40% coupon days at HL.

I haven't read a Pinewood Derby rule set in about 40 years, but the car I built then had plenty of room for whatever kind of weight you'd want. Is the volume of ballast now restricted somehow?

I like the idea of the putty because it's easily squished into convenient shapes, which may allow it to be used in tighter packaging than a more dense but fixed form weight.

 

[bad_idea]

You can also get tungsten powder at golf shops, I've read. Then you can mix it with epoxy and pour/squish it into whatever cavity you want it to fill and it self-conforms and is automatically attached.

In practice, I believe epoxy/powder will be most efficient, but it's worth noting that a perfect mix is still going to be 26% epoxy (assuming your tungsten particles are spherical and roughly equal in size), and you're not going to get a perfect mix. Depending on the shape of the cavity and the shape of a solid piece of tungsten, the solid piece might come out ahead.

I have some tungsten powder I'll try someday if I ever need to add noseweight to a high performance build. Lead shot is a lot cheaper though, so I'll continue to use when needed in less-optimized builds.

 

[Azamiryou]

Looking at the densities, tungsten is quite a bit denser than lead, but the putty is about the same as lead. I'm sure it's similar if you mix it with epoxy yourself.

 

[Rob Campbell]

I just use my go to which is LEAD. As long as you don’t eat it, you will be fine.

Tungsten is interesting.

 

[mjennings]

I haven't read a Pinewood Derby rule set in about 40 years, but the car I built then had plenty of room for whatever kind of weight you'd want. Is the volume of ballast now restricted somehow?

I like the idea of the putty because it's easily squished into convenient shapes, which may allow it to be used in tighter packaging than a more dense but fixed form weight.

Fun cars still have lots of room to get to 5oz, fast cars are all thin wedges with the weights in the back. It's not a rules limitation but an engineering one, right amount of weight in the right place. Our district is very strict on rules and is very competitive. We made it to districts every year and only placed in top 50 once. Also my son did a lot of work, I guided, unlike some dads.

 

[kjhambrick]

Speaking of Tungsten -vs- Lead ...

I am trying to figure out a way to securely install variable nose weight into a new rocket design.

The bullet weights I inspected at Mr Jenson's Fishing Store won't pack well in my nose cone along with the tracker and av-bay I want to install in there too ...

I need to control the shape of the weights wrt the interior of my nose cone ... something semi-conical for the best density / length.

I don't think I'll be casting any Tungsten with a melting point of 3,422 C ( 6,192 F )

But I am looking locally for some Tungsten Powder so I might try to make a set of variable diameter 'composite' washers with epoxy and powdered Tungsten.

OTOH, It would be easy to cast a set of Lead washers and pure Lead at 11.34 g/cc very well might end up being denser than a mixture of Tungsten at 19.25 g/cc and epoxy at about 1.2 g/cc.

As long as I don't eat my purty Lead Neco Wafers

And assuming a 50:50 mixture by volume, I come up with 10.23 g/cc, but maybe I can increase the metal::epoxy ratio -- it might be fun to try it

Speaking of cars, this was a fun read: Building Speed > Ballast: Tungsten vs. Lead

Anyhow ... still studying ways to get a lotta mass ( about 3 oz ) in a tiny volume ...

-- kjh

 

[Banzai88]

Tungsten powder is readily available, as is tungsten putty for fishing/golf/hobby uses.

Price depends on vendor and advertised end use case......but none of it is cheap.

 

[kjhambrick]

Tungsten powder is readily available, as is tungsten putty for fishing/golf/hobby uses.

Price depends on vendor and advertised end use case......but none of it is cheap.

Yes it is !

I found some Tungsten Putty at Hobby Lobby on the Pinewood Derby Rack.

Hobby Lobby > Tungsten Putty Weight


It's nice and squishy and not too expensive $5.99 / oz, but it didn't seem as dense as an ounce of lead.

I have been casually shopping Tungsten powder and there are a lot of sources but I've got a little time before finish my fins and I need to add nose weight.

The best price I've found is $27 / 4-oz on EBay with my casual searching ...

OTOH, I've got a little pure lead left over from my old muzzle loading bullet casting days and it's been a while since I melted lead in a tin can on a hibachi

That would be fun for old time's sake so I may start with a set of cast lead washers ...

-- kjh

 

[Blast it Tom!]

Hmm... putting some numbers to it, solid tungsten at 19.3 gm/cm³ is 1.7x as dense as lead at 11.3 gm/cm³. But both are generally inconvenient to use in solid form, though lead is far easier to cast.

Per this site, the tapped and bulk density of tungsten powder are both greater than lead (I suspect they reversed the values as tapped is supposed to be > bulk). So if that's what you're after, then it's just containment which becomes an issue. Of course, containment affects overall weight volume as well.

 

[kjhambrick]

Interesting idea, @Blast it Tom!

I had not thought of making a container full of Tungsten powder and then somehow securing the container into the nose behind the Aluminum tip !

That might be fun too

Thanks for the link !

-- kjh

 

[NOLA_BAR]

You can get diving weights which still use lead shot off eBay. Just search for soft mesh lead shot diving weight. Typically, 1 to 5lb sizes.

 

[SolarYellow]

Speaking of cars, this was a fun read: Building Speed > Ballast: Tungsten vs. Lead

There's one thing in there that's fundamentally wrong.

Grip is proportional to how hard a wheel is being pushed into the track. Left-turning cars have a challenge keeping weight on those inner wheels, so putting ballast on the left side of the car helps with left-side grip.

If grip was proportional, then more load on the right-side tires would increase the grip proportionally, and the only loss of performance would be tire life. In reality, the effective available coefficient of friction from a tire is curved downward, away from a straight proportional slope as load increases. So if you increase the load on a tire to 1.2x, you don't get 1.2*grip. The slope decreases as load increases, so the tires that get more load don't increase grip enough to offset the grip lost by the tires that get less load. You get less total grip. The optimum possible is to have all tire contact patches loaded equally. In a car that only turns left, you want to put more static weight on the left-side tires, so that the reduction in overall grip when weight transfers to the right-side tires is minimized.

I know it's not really relevant to this thread, but that is so fundamental to vehicular performance (what I do for a day job) that I couldn't let it slide.

 

[kjhambrick]

<<snip>> ... I know it's not really relevant to this thread, but that is so fundamental to vehicular performance (what I do for a day job) that I couldn't let it slide.

Maybe not relevant, but such things are fun to ponder

-- kjh

 

[Azamiryou]

I couldn't let it slide.

I see what you did there!

 

[lr64]

Seems like a tungsten nose cone weight, if the right size and shape, could be an excellent refractory tip for your hypersonic rocket at the same time. Screwed into copper, which gets screwed into aluminum... Stop before you get to gallium.

 

[Blast it Tom!]

Just wondering... I'm no chemist, but if CA "wets" tungsten powder, perhaps the best way to get it shaped and still retain a high bulk density would be to tap it in place and then use the super-thin CA to just wick into the spaces. Might be worth an experiment in high density is very important.

 

[kjhambrick]

Just wondering... I'm no chemist, but if CA "wets" tungsten powder, perhaps the best way to get it shaped and still retain a high bulk density would be to tap it in place and then use the super-thin CA to just wick into the spaces. Might be worth an experiment in high density is very important.

@Blast it Tom!

Holy Cow !

Why didn't I think of that ??

That IS worth an experiment !

So now I'll order the Tungsten Powder I have on hold and post my findings here.

-- kjh

 

[lr64]

Densest with a mix of particle sizes, probably.

 

[rocketace]

Tungsten powder is definitely most compact options. I was looking at it for my BadaBoom rocket, but ended up deciding on just lead shot. I could still get the added weigh I needed in the space and lead was a lot cheaper. I also made up some containers that to hold the lead shot in different configurations (caps for each one not shown).

https://www.amazon.com/gp/product/B0D3J7G5CQ/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

 

[cwbullet]

Tungsten powder is definitely most compact options. I was looking at it for my BadaBoom rocket, but ended up deciding on just lead shot. I could still get the added weigh I needed in the space and lead was a lot cheaper. I also made up some containers that to hold the lead shot in different configurations (caps for each one not shown).

https://www.amazon.com/gp/product/B0D3J7G5CQ/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

View attachment 686837

I use this or lead powder for golf clubs. The stuff for clubs is a little but it comes in little bottles for easy dispensing.

As said, tungsten is more dense and safer, but it costs 7 times more. Lead is safe as long you don't eat it or breath it.

 

[kjhambrick]

I use this or lead powder for golf clubs. The stuff for clubs is a little but it comes in little bottles for easy dispensing.

As said, tungsten is more dense and safer, but it costs 7 times more. Lead is safe as long you don't eat it or breath it.

$50/22 lb for #7.5 bird shot is certainly a better deal than $70/lb for 300-mesh tungsten powder !

Ballistic Products > Factory Lead Shot US #7.5 (22 lb)

-vs-

300Mesh Pure High Density Tungsten Powder

I need to see if my brother Mike has 3-or-4 oz of bird shot left over from our reloading and quail hunting days.

And I love @rocketace's kool kontainers with the axial screw hole !

I HAVE TO get into 3D printing some day soon !

-- kjh

I imagine if I have to buy some, I would go with #8 or #9 shot and I should be able to get it from Academy or Outdoor World