the sand will not fall the picture has too much air.
To correct the condition pull out the ¼" wood dowel that
the picture turns on
a syringe (up to a 3cc syringe with a 1½", 22 gauge needle) through
the dowel hole into the space between the two pieces of glass
Add distilled water
Turn the picture so the end of the needle is in the
air and extract air
Be sure to remove by volume as much air as you added
If the sand is going too fast do the opposite of that
described above. That is add air and remove water.
Always start with a full syringe (have the plunger all the way
back and return it to the same position before removing if from the
If you are not certain that the same amount has been removed
take the plunger out of the syringe and insert the open syringe into
the picture with the syringe on top, allowing it to stand 1-2
minutes. This will equalize the pressure inside to that outside.
If the volume of air changed readjust again.
Hints for better performance
If the picture has not been used for several hours, shake it to make small
bubbles out of the large ones.
When you turn the picture over have the top of the picture slightly toward
you. The white sand will then fall on your side and vein (striated) the
picture making it more scenic.