Does anyone know if it is possible through some sort of injection/compression molding to produce a tungsten powder bulb of greater density than lead. If it is possible then will we not have to measure the density of any bulb submitted at measuring?
I would like to vote YES with respect to schools etc but would have to vote NO if a keen racer could produce an illegal bulb which we cannot easily measure. Something which can be done now anyway by the unscrupulous I suppose.
Graham
It is possible to get the specific gravity of sintered tungsten powders up to about 15.5 - 16 without using rocket science (although a leetle more than jitchen table technology). SG of lead, about 11.3, SG of solid tunsten, about 19.3, so there is a big difference. On the other hand, although composites can be made that are denser than lead, the amount by which they are denser is less. I’m guessing, but I would be surprised if an SG much in excess of, say, 13.5 was possible.
There is the opportunity for cheating, but it is also there is at present. When did you bot check that the guy who beat you (or came last) did not have a solid tunsten bulb? Or osmium (SG 22.6!)? If a composite is used, you are at least aware that something MIGHT be fishy.
Remember also that dense ballast does not add up to a magic bullet (unless you are a Bulgarian journalist working for the BBC - in hich case it is also a pain in the butt). The linear/square/cube relationship means that the high density bulb is not that much smaller in its frontal area or surface area than a legal one. If were in the cheating business, I could think of better things to occupy my time.
Incidentally, did you know that ‘tungsten’ is Swedish for ‘heavy stone’?
:devil3::devil3::graduate::zbeer:
It would take more than injection molding to get powdered Tungsten to solidify more densely than lead. Remember that powders are mostly air, so you’ll need a way to remove all that air, like if you melted the metal. Even mixing the tungsten powder with resin won’t be any denser than solid lead.
Thanks Angus for the reply, you have answered my curiosity as to how difficult it would be to produce a denser bulb quite nicely 
Graham
I understand what your concerns are Graham but we don’t tests bulbs now. I could have a few tungsten weights inside my lead bulb and who would know. We could measure density if the bulbs were required to be removable, but we don’t. Footy skippers are honorable folks, I’ll take the risk to gain the benefits.
See here for purchase (RG65 had no lead rule. I’m probably too cheap to try it though.)
http://www.pinewoodpro.com/pinewood-derby-tungsten-weights.htm
Graham,
I share your thoughts and concerns, but you are correct, such keel weights could already be in use, how would we know? The only way I can think of to test them would be to scratch the bulb with an exacto knife - pure lead could be scratched easily (or even shaved!), while tungsten is quite hard, even if used in powdered form mixed in resin. Unfortunately, this would be somewhat destructive, and probably unacceptable to those who work hard to achieve a nice finish on their models. Also, I suspect the original intent of any rule regarding the bulb was to limit the use of potentially harmful materials such as depleted uranium, and as near as I can tell, tungsten is less hazardous than lead (though much harder to work). I plan to vote yes, since the old rule is as equally hard to enforce as the new rule would be.
Regards,
Bill Nielsen
Oakland Park, FL USA
Toxicity. The US government agency responsible for these things rates late as (I think) the 4th nastiest subsance on this planet. Tungsten doesn’t even come into the reckoning. If I rember rightly it can cause temporary psychiatric disorders on many years of near-contunuous exposoure to tungsten powder without breathing protection - or something like that.
I know that lead doesn’t turn your teeth blue as soon as you look at it, but it is nasty stuff. Worse, bureaucarats (a worese, mini bureaucrats) have heard of it and know its A Bad Thing. This makes things like schools extremely jumpy about lead.
:graduate::zbeer::zbeer:
Schools are careful of lead because chiildren are more sensitive to its effects than adults, and we want them to grow up as best as we can- even bettering ourselves (possible? :sly: )
Hi guys
Sorry to come in so late on this thread. Tungsten has my attention at the moment because (I think!) it will be much more easily available in a couple of years in a shape that would be seriously useful to model sailors. The reason is the number of e-mails I receive from Chinese metal foundries who are waking up to their global market and the ease with which they can deliver 100-off batches of anything from a DXF file!
Sorry to disagree with Angus, but I believe a tungsten bulb would turn any so-so boat into a winner overnight. The major factor in bulb drag as far as I can see is the volume of water which gets “pushed” aside as the boat moves through the water. Tungsten could reduce bulb volume by up to 30%…
If tungsten is permitted, I’d expect to see winning Footys with tungsten bulbs within two years (smile)…
Lead, wonderful stuff, I attribute my obsession with Footy’s in part to a tendency to chew on toy solders when I was a tot. My wife tells me that I’m mad as a hatter;)
I thought hats was a mercury dressing? One of the classic occupational groups to suffer from lead poisoning used to be publicans - drinking the first pint to be pulled after the beer had been standing in lead pipes duing closing time.:zbeer::zbeer::zbeer:
Yeah you’re right Angus, my lead consumption probably killed my brain cells causing the memory loss resulting in confusion over lead and mercury poisoning. The lead pipes in pubs must be an ancient northern thing, probably inherited from the Romans. In my uncles (southern) pub in the late 50’s the taps were fed by copper pipes. , As a kid I used to ‘help’ change kegs (big wood things in those days).
Gad the cheek of them there s’thners.
Speaking of lead history… as I was relating to Angus only yesterday I spent two years as ‘school printer’ as a kid. I set lead type, backwards of course, and dealt with ‘leading’ for real, add another strip of lead. All of this in break and lunch times which was a great way to avoid the riff raff in the playgound and of course I ate my sandwiches too.
After school I worked in a small company in Sheffield for the next 20 years which had lead water piping until the day it closed. Yup at least four brew ups a day and the morning one had that extra tang I guess it’s too late for me but I must admit I do now take much greater precautions while casting footy ballasts. Nitrile gloves, plenty of fresh air despite the cold and lots of hand scrubbing! I suspect that cutting carbon tubing is probably worse despite the face mask. So what happens if you sneeze over your tungsten powder?
Lester’s post does concern me though. but at least if solid tungsten were used it would look small compared to solid lead. Small enough that it would be suspicious if the boat looked as stiff on the water with as much sail as other boats. The composite route would from Angus’ figures muddy the waters because the gap could be legally bridged.
Interesting dilemma.
Graham
I reckon that tungsten is much more expensive than lead. That fact alone will discourage some modelers. More than that, the stuff is not readily available at places like Wal-Mart. One source for solid tungsten is the machine shop that does crankshaft balancing. They use small slugs to insert into bobweights where extra weight is needed. A really evil method of increasing bulb density would be the use of mercury. Real nasty stuff and an ecological as well as biological hazard. Some world war two submarines used mercury for ballast.
The effort for enforcing rules to ban exotic ballast might be difficult, as discovery would be a source of argument. I would vote NO to any rule that permitted tungsten, platinum, or whatever. I suppose that there are a few who will do anything to gain advantage and it will be difficult to thwart them. Those of us who obey the rules will have to take our satisfaction from the knowledge that we compete on an honest basis.
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I contemplate the scenario where someone’s boat loses its keel in the pond, and some spectator says–“Lead, hm? My granddaughter paddles in this pond, and she has just been diagnosed with lead poisoning.”
Will they let anyone sail in the pond, ever again?