weight question

[TNdiver]

Does anyone know how much more weight you would need in steel weights compared to lead weights? I cant get a lead weight belt around here, so i made one out of a nylon webbing belt i had, and a set of ankle weights. The weights are steel, and when i was practicing in the lake yesterday i noticed that 8lbs was just BARELY enough to keep me down in 20 feet of water (no suit). If i figured it right i should need about 1.5 times the weight of steel vs. lead. Anyone else have any input?

 

[trux]

The weight (not the volume) difference in lead vs. steal needed for the weights will be quite minimal (around 5%). Although the volume of the steel weight will be indeed about 1.3-1.5 times bigger than at lead (depending on the type of the steel), the added buoyancy due to the 40% higher volume will be only about 5% (because water replaced by the extra volume has the density ~8 times lower than steel >>> 40% / 8 = 5%).

However, although you do not need significantly heavier weights when using steel, it is still inconvenient because of the increased volume. I remember I had similar problem about 20 years ago - there were no dive shops in our country in that time, so I simply made a plaster mold and casted a series of lead weights myself. It was easy and quite quick. In fact I still use them today on one of my belts and I am pretty proud of them - they were quite nicely designed I think I'll have to make a photo and post it here. It is very easy to find the needed lead - old plumbing pipes, car accumulators, etc. And the melting of lead is quite easy and quick - you can do it over a gas burner in an old pan.

Even simpler - if you are too lazy to to mess with the foundry, simply get lead shot and fill small pockets attached on a belt with it.

And if you are in a lucky zone of influence of the US military spreading their democracy, then you can do even much smaller weights. The democracy is always being spread together with (or maybe even attached to) depleted uranium (DU). So if you are in the Balkan, in Iraq, in USA itself, or in some of other such locations (see below), you can make your weights almost just the half the size of lead ones.

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Uranium has the density 19 times higher than water. And according to the Pentagon and US authorities, you do not need to be afraid of the radioactivity or poisoning - they claim it is harmless. Well, the increased number of cancers and newborn malformations in concerned countries is shooting tenfolds and more, but according to the US authorities, it has no relation, so you can be pretty unconcerned. Although DU is not popular in mass media, you can find a lot of information about it all over Internet, including many reliable sources (like WHO, ACENTER, ...). For example here, here, here, here, [ame="http://en.wikipedia.org/wiki/Depleted_uranium"]here[/ame],... or simply here.

Hmm, if you are one of those who do not believe governments, then you may try using tungsten instead - it is even little bit more dense than uranium (19.3 vs 19.0) and it is not radioactive. It is pretty difficult to machine though, so you may have hard time getting the right shape. And as most other heavy metals (including lead), it is poisonous, so it should be handled carefully - vapors, oxides, particles, dust can be fatally dangerous or can cause irreversible damage to the organism!

 

[trux]

OK, I've made a photo of the home made weight. I have only a single weight at home. When looking at it, do not forget it is more than 20 years old and often used also in sea water, so it is already quite damaged. The belt with the other weights is in my summer house at the sea. It was also home made, because as I told, in that time it was very difficult to buy such material in my home land. I made it from a nylon belt I managed to find in some industrial shop, and made the security buckle myself from aluminum plate too. It was quite easy and relatively quick to made it all, but it is true that today you can buy such material easily at very low cost, so I would certainly not bother with it anymore

photo © trux​

The molding of the weight was done in this way:

1. [~20 min] I made a model in plasticine
2. [~5 min] I've filled a box with liquid plaster, then pressed the plasticine model into it with the flat side up (like on the left side of the photo)
3. [~5 min] When the plaster mold was dry, I removed the plasticine, made some correcting and let it dry a day
4. [~15 min] I fonded the lead on a gas cooker in an old pot and poured it into the mold
5. When cooled down, I removed it, and casted the next one.
6. [~10 min] I then worked/cleaned the edges and openings - it is very easy with lead
7. [~5 min] I painted them with thick layer of protective color (after the 20 years of use you can see only the rest of the original orange color, but it is still the original one)

When working with liquid lead, and when working it afterwards, use protective tools (gloves, respiratory mask, glasses, apron,...). Do not forget that heavy metals are poisonous, so urgently avoid inhaling or swallowing of particles or vapors, or working/machining the lead with bare/uncovered hands - the particles might get into bruises of your skin. Do not work it in interiors or close to habitable area, where the particles could stay for years.

 

[TNdiver]

thanks for the weight making bit, but id really rather use what i have if i can, and what im really after here is the coversion of lead to steel that i would need.

 

[trux]

thanks for the weight making bit, but id really rather use what i have if i can, and what im really after here is the coversion of lead to steel that i would need.

Yes, I understood that and explained you in my first reply that the weight needed in steel versus weight needed in lead are practically identical. The 5% of the buoyancy difference are really minimal and you'll barely feel it.