OK - I saw the post on how Silicone doesn’t float cuz it’s specific gravity is higher than 1…

Now - what would happen if I took two materials - one’s SG is less than one and the other is greater than one…

Will the material who’s SG is less than 1 float to the top and the other just hang in the water?

I would like to make a part where one piece floats to the top and the other stays submerged…is this just a function of surface area or amount of each material?

any help you can offer?

Will the material who’s SG is less than 1 float to the top and the other just hang in the water?

To an extent … it would depend upon the respective materials; their SG, and volumes (displacement). *Intuitively*, think of a piece of steel the size of a wooden pencil, glued to the pencil. Is the combination going to float?

… is this just a function of surface area or amount of each material?

Volume/Specific Gravity, not surface area (surface area is two-dimensional); the surface area of a cube is different than it’s volume; i.e. a 1" x 1" x 1" cube has a “surface area” of six *square* inches, the volume is, obviously, one *cubic* inch. Which weighs more, a cubic foot of steel, or a cubic foot of feathers?

You have an almost infinite variety of materails to choose from for your project, it’s just a matter of finding those with compatable characteristics.

Lmo - thanks for the response!