I have a liquid wave paperweight that I’ve owned for about 25 years. When I first got it, the volume of clear liquid and denser blue liquid were about equal, but in the past few years I’ve noticed the amount of blue liquid getting smaller, to the point where it now barely covers the bottom surface.
The total volume of liquid doesn’t seem to be decreasing, though I admit that I haven’t made any marks on the container to confirm this, so I could be wrong.
There are no stains on the wooden bookshelf that it’s been standing on for years, so I know that it isn’t leaking. The container should be airtight, so I don’t think it’s evaporating. It’s almost never been exposed to direct sunlight, and it’s always at room temperature.
So what’s happening? Is the blue liquid gradually becoming clear? What kind of chemical reaction is taking place? Does it have a half-life?
Possibly the liquid portion of the denser blue liquid is slowly mixing with the less dense clear stuff but the coloring agent isn’t soluble in the clear liquid. I had a similar kind of thing that lost liquid over time, I just assumed there was a tiny leak somewhere and the liquid was evaporating.
For what it’s worth, the denser liquid is almost certainly just plain ordinary DHMO, and so a sufficiently-slow leak of it could very easily go unnoticed.
Does anyone know how to repair these? I’ve got some I like that are low, but I can’t find anything on the internet as to how to refill them, or with what. Is it as easy as just adding more water?
OTOH, I had a nice Titanic one just like the OP’s (it had a ship and an iceberg). One day, the densities must have changed, as both the ship and the berg were on the bottom. Later, there was a large blue mess under the box. It must have dissolved whatever sealant was used. That one was not just water.
It had to have been more than just water: The denser liquid (which is probably water) has some sort of dye or coloring in it, and the less-dense liquid is probably some sort of oil. Any sort of leak that would cause noticeable changes over the span of a day would likely also involve a significant portion of the oil leaking out, too, which (along with the blue dye) would account for the “not just water”.
Ruken: The container is probably Plexiglass, though it feels like glass. The walls seem pretty solid. It’s capped on two sides with plastic, and I’m not sure how that’s fastened on.
The clear liquid probably is mineral oil. The blue may be water, but it behaves strangely; if the paperweight has gone untouched for days, and then I turn it over, there are coagulated patches of blue clinging to the top like blobs of gelatin. I have to shake the paperweight briskly to clear them off. Maybe this is normal, and the water is being held on the “ceiling” by a film of oil. Is that possible?
Chronos: I really doubt that there could be a slow leak that didn’t leave any mark or stain on the finished wood shelf. But I won’t say that it’s impossible.
What’s unusual about drops of water clinging to a surface? You see that with wet things all the time. It only looks different because the weight of the water is almost entirely supported by buoyancy from the oil.
I regularly bathe in the stuff. I read on the intertoobs that it makes you immune to the harmful effects. I buy it from a specialty online store for $75/gallon.
Sizable water drops usually slide downward when the surface is tilted. These stay in place, even when I rotate the paperweight 360 degrees around the X or Z axis. Brisk shaking is the only way to dislodge them.
And there’s no buoyancy involved. The level of the oil is more than a half inch below the top of the container.
Oh. I’m not sure, then. It almost has to be slightly-impure water, since that’s by far the cheapest thing you could use in one of these things, and why would you want to use anything else? But I don’t know why it would behave like you describe.
