If you have fine sand and sea water what kind of structure can you build?

Sand castles! Waiting for the more scientific replies. If there are any.

You need a binder. Many plants and trees can provide gum to accomplish this. It is best to use a gum that will harden over time and not remain elastic. One way to do this is by the removal of moisture from the gum. This could be accomplished through evaporation in sunlight. Or it may involve another vegetable ingredient, an emulsifier, to the recipe to cause an elastic gum to harden sufficiently. A protein would probably work. No water needed in this mixture.

Another binder is lime. Lime deposits are very common especially inland from sandy shores and on alluvial plains. This involves water. Fresh water is much better to use than salt water, because the salt crystals interfere with the integrity of the mixture during the hardening process. So, the sea water would have to be distilled in order to separate the salt from the water. That is a simpe process. .

Waiting for Luckyguy…

I’m going with sandcastles and sand sculptures too.

You can make sand art with the sand alone. Water vaporizer can be used to gently moisten the sand art with sea water, and let it dry to add a little bit resistance to the sand art.

You can also build public sand therapy facility depending on the type of sand and geothermal environment. The sea water, which is free, can be recommended as additional sea water therapy following the sand bath therapy (at least it should be marketed that way). You just need good advertisements of why the your sand and sea water are beneficial for people’s health and they’ll use your facilities.

These are all I can think of since you limit the materials.

^^ Seawater contains Dopamine which is released into the air via evaporation along the seashore. Dopamine in these trace amounts works as a mood elevator. Although people have been unaware of this until the twentieth century, it is considered one of the reasons humanity around the world have instinctually gravitated to the seashore. It makes them feel better. Explaining this and convincing people that your shore has more Dopamine than other shores would bring them in.

@Espiritus_Corvus Interesting, I never knew that!
Now if they would jut infuse the water supply with a little Lithium we’d all be so happy. lol

^^LOL. That has actually been seriously discussed. BTW, Lithium is released from seawater as well. They are both produced by certain algas, their only known natural sources. So, I suppose if @Unofficial_Member wanted his advertizing to have any real truth in it, he would pick a beach where more of these offshore algas are found than off other beaches . He might have something there.

I’m going to look for my bucket and spade. See you later down the beach.

^^ CAn a penguin come help? Flippers are good for smoothing..

A source of clay would be ideal to mix into the sand and sea water. Any nearby river bank will afford you a nice supply of that. Any additive like coal dust, corn flour, dextrin, plantfiber, wood flour, silica flour, animal or human poo would add additional strength to your mixture. Form into bricks and let dry for a couple days and build whatever you want.

Can I use tools?

@areyoukiddingme yes, but not tools that make loud noises, nor other beach unfriendly qualities

With a large lens or reflector you can use solar energy to melt the sand and make glass. Use it like a big 3-d printer.

If you can get lightning to hit sand, you can make fulgurite: https://en.wikipedia.org/wiki/Fulgurite

@janbb Sure you can come but I’ll have to quality check your crenellations.

That’s what I was going for, I’m fusing the sand into a weak glass making it any shape I want using an assortment of torches
.

@flutherother is that what they’re calling them now?