Heavy, flat and cheap?

October 14, 2005 6:26 AM

What is the heaviest object that would fit inside a standard letter-sized envelope?

This is for personal reasons, nobody's going to get hurt, I promise.

I need to find the heaviest object or material I can put into an envelope. It needs to be heavy, flat and cheap. It should also be easily obtainable. The atomic weight of Abevigodium might be 98379, but if I can't find it at Home Depot it's not going to help. I want the end result to be an envelope so heavy God himself would need to stop and catch his breath on the way to the post office.

posted by bondcliff to sports, hobbies, & recreation (36 answers total)

Perhaps if you filled it slowly with epoxy?
posted by odinsdream at 6:30 AM on October 14, 2005

Iron filings? Maybe iron filings in a bag with the air sucked out?

Neutronium.
posted by ROU_Xenophobe at 6:38 AM on October 14, 2005

How about lead? It's cheap, heavy, and you can buy it in sheets. Only problem is that it might be too heavy-- it would probably want to rip the envelope.
posted by justkevin at 6:40 AM on October 14, 2005

You're screwed.

All the really dense stuff (platinum, rhenium, iridium) is wicked expensive.

Maybe call these guys?
posted by Kwantsar at 6:42 AM on October 14, 2005

Wikipedia has good article on density. I'd go with lead or tungsten. You could melt the lead into a thin plate. Mercury would slosh making the envelope hard to carry. Of course, you'd have to find something to hold the mercury in.
posted by malp at 6:43 AM on October 14, 2005

Lead Foil.
posted by alms at 6:46 AM on October 14, 2005

Good suggestions so far. I should also add that it should be safe and mailing it won't make the Department of Homeland Security get medieval on my ass.
posted by bondcliff at 6:47 AM on October 14, 2005

Only problem is that it might be too heavy-- it would probably want to rip the envelope.

Don't think of it as a container, think of it as a wrapper. I think in line with the wishes of the questioner it would be so full as to restrict any damaging movement.
posted by biffa at 6:52 AM on October 14, 2005

If you filled the envelope with mercury you'd also most likely be looking at being accused of shipping hazardous materials. Lead would probably be your best choice. If you had to you could go to your local hunting/fishing store and buy it, melt it down and shape it how you'd like. It's very malleable so you could always brute force it into sheets with a hammer.
posted by substrate at 6:55 AM on October 14, 2005

You want tungsten, it is 70% denser then lead (19.25 g/cm³ vs. 11.34 g/cm³), 1% denser than depleted uranium (19.25 g/cm³ vs. vs. 19.05 g/cm³), and only slightly less dense than gold (19.25 g/cm³ vs. vs. 19.30 g/cm³).

ESPI specializes in supplying small quantities of materials for research, they have no minimum order, and they sell tungsten sheet from .010” to 1” thick and will cut it to order. They sell lead sheet as well, if tungsten turns out to be too expensive.
posted by RichardP at 6:56 AM on October 14, 2005

Oh, and by the way, a 1/8" thick sheet of tungsten cut to fit a standard 9 1/2" x 4 1/8" letter-sized envelope would weigh more than three pounds!
posted by RichardP at 7:16 AM on October 14, 2005

You're not doing this one of those self-addressed return mailer things right? Because the post office won't deliver it.

Since you mention you're going to mail it, it will need to be weighed, the post office has a weight limit on first class postage.

If it's just a prank for your buddy... I'd say go with lead, it's the cheapest thing that weighs a lot, and you won't have to mail away for it.
posted by inthe80s at 7:22 AM on October 14, 2005

I assume this is a prepaid return envelope? The last time I read about somone filling those with something heavy it was lead pellets that were melted and poured into the envelope. Another person used iron shavings.
posted by GrumpyMonkey at 7:29 AM on October 14, 2005

Tungsten is going to be crazy expensive and hard to shape though.

A 6"x6"x1/4" piece of lead (weighing 16 lbs), goes for $21.71 from McMaster Carr and he can cut it to fit easily with a $5 hacksaw.
posted by bonehead at 7:32 AM on October 14, 2005

Ooops. Misread. that's 16 lbs/sq foot. So your 6"x6" sheet would be 4 lbs. or so.
posted by bonehead at 7:33 AM on October 14, 2005

Btw, it's easy to melt lead on the stovetop, but it's only a good idea if you enjoy the sensation of permanent central nervous system damage. It's a much better idea to shape it cold.
posted by bonehead at 7:36 AM on October 14, 2005

A 4 x 9 x 1/2 inch gold ingot would probably fit into a No. 10 envelope and weigh about 12 1/2 pounds (avoirdupois), but at current gold prices would cost well over $85K. I would stick with lead. A similar lead ingot would weigh about 7 1/3 pounds.
posted by caddis at 7:53 AM on October 14, 2005

I don't have any ideas, but I really want to hear the story behind this one.
posted by Lotto at 7:54 AM on October 14, 2005

RichardP hit the nail on the head. Tungsten is just about the perfect triple point for heaviness, cheapness, and availability. Lead is good, too, if you put a premium on cheap. Maximum size for letters (not packages) in the US postal system is 11½ x 6¹/₈ x ¾, which would be almost 37 pounds for Tungsten. Priority Mail cross-country, that would cost $63.85 to mail.
posted by Plutor at 7:57 AM on October 14, 2005

I thought stupid entities were working. That's 11 ¹/₂ x 6 ¹/₈ x ³/₄,
posted by Plutor at 7:58 AM on October 14, 2005

Is this for those junk mail business reply envelopes?

I may have to buy some tungsten just to play around with... would be cool to have some super-heavy marbles.
posted by rolypolyman at 8:07 AM on October 14, 2005

a black hole ... how one would get it in the envelope or get the envelope to last more than a millisecond is beyond me

you would have to mail it at the post office ... letters more than 18 ounces aren't supposed to be mailed in mailboxes ... and the postage would probably be very expensive
posted by pyramid termite at 8:14 AM on October 14, 2005

bonehead writes "he can cut it to fit easily with a $5 hacksaw."

Don't hacksaw lead you'll get toxic filings all over the place. Pure lead is easily cut using a sharp knife or metal shear. Or you can chuck a flat tip in a soldering iron.
posted by Mitheral at 8:27 AM on October 14, 2005

Or you can chuck a flat tip in a soldering iron.

Make sure you're well ventilated; lead vapors are much worse than toxic filings and dust.
posted by ikkyu2 at 8:34 AM on October 14, 2005

Yes, of course, I should have mentioned that. Be careful not to burn yourself as well.
posted by Mitheral at 8:49 AM on October 14, 2005

Lead is too heavy to aerosolize as dust and filings are easily swept up. Disposal is another problem, though.

Also, where is this source of cheap tungsten? MC has 90% tungsten alloy at about $32/cu. inch. To get a similar volume as the 6x6 lead sheet I mention above would be over $275.
posted by bonehead at 8:55 AM on October 14, 2005

If it's for the junk mailer, I fill it with other junk mail, so it's psychologically heavy.
posted by weapons-grade pandemonium at 9:19 AM on October 14, 2005

Maybe the mythbusters guy who posts here can help out?
posted by Saucy Intruder at 9:36 AM on October 14, 2005

It needs to be heavy, flat and cheap.
glass
posted by thomcatspike at 9:44 AM on October 14, 2005

or you could use sand
posted by thomcatspike at 9:44 AM on October 14, 2005

You could glue the lead into the envelope to keep the envelope from tearing.
posted by malp at 10:12 AM on October 14, 2005

Possibly relevant?
posted by trondant at 10:21 AM on October 14, 2005

A non-toxic alternative to lead would be tin. You could get a roll of non-toxic tin solder (without a flux core) 1/8" diameter, and make a flat spiral that would fit in an envelope. Also, you could get some non-toxic shot for reloading shotgun shells: tungsten alloy, bisthmuth and others are now used. See hevi-shot. You'd have to stick the shot to something flat to keep it from running to one corner.
posted by 445supermag at 11:50 AM on October 14, 2005

You could always use one of those flat-rate priority mail envelopes and only spend $3.85. And it can have the footprint of an unfolded letter sheet of paper.
posted by oaf at 2:45 PM on October 14, 2005

As idle curiosity this thread is interesting.

I hope you don't actually intend to try to stuff a business reply mail envelope with tungsten, because it would be treated as trash by the USPS. If you're trying to do this to cost someone money, forget it.
posted by Rhomboid at 10:32 PM on October 14, 2005

You can buy sheet lead by the foot in widths up to 12" at any decent lumber yard. When you get it home you can cut it to size with a utility knife. You could probably stuff two pieces in an envelope (maybe even three). It's soft so you can easily scratch your message on it with a hard tipped scribe. Are you replying to all of those credit card offers? If so, tell them to leave me alone too!
posted by sgobbare at 8:13 AM on June 21, 2006