Vacuum Filtration for Water Drop Photography

This Instructable will cover an inexpensive way to create a small manual vacuum pump to radically reduce filtration times when preparing viscous gum (guar gum or xanthan gum) solutions for water drop photography.

When a (relatively) thick solution drops into a liquid with low surface tension it creates taller and more interesting splashes. This is an important element in water drop photography.

My set up for water drop photography varies, it can involve two to four flashes, some kind of background, a variety of catch trays and it always includes a Miops Splash to not only control the drops but the camera and flashes. I highly recommend trying one out if you want to start shooting water drops (BTW, I'm putting together an 'Ible for that too)

Preparing the drop solution for this kind of project has always been a time-consuming pain. I've been using a (gravity) filtration flask and Buchner funnel for a long time but didn't want to purchase an expensive vacuum pump. Since preparing these solutions takes a very very VERY long time to filter with just gravity filtration it made me shoot less often. And that was really disappointing. So I took the same glassware and upgraded to vacuum filtration. Now, the prep time is cut down to less than five minutes. This means getting to work whenever inspiration strikes and no more making gum solutions ahead of time that spoil and smell. Just mix, filter and shot.

WARNING

• Only use glassware designed to hold vacuum
• Always wear safety glasses
• Inspect the glassware for cracks before each use

• Tubing
  • Aquarium tubing ~10-15 inches
  • 3/8 in outer diameter tubing ~ 3 inches
  • 3/8 in inner diameter tubing ~10 inches
• Aquarium "T"
• 2 Aquarium Check valve
• Hot GlueGun
• Sheers/scissors
• Glassware Kit
  
  • Flask
  • Rubber Stopper
  • Buchner funnel
  • Filter paper
• Safety glasses
• Something viscous to filter

• Cut three pieces of aquarium tubing to ~ 1 inch
• Cut a fourth piece of aquarium tubing to 8-10 inches
• 3/8 in outer diameter tubing ~ 3 inches
• 3/8 in inner diameter tubing ~10 inches

Layout the parts in order and in the proper orientation.

The red arrows in the above image, represent the flow of air through the check valves.

Please note the orientation of the check valves. Double check before installing them

• Take a piece of aquarium tubing and slide it onto the check valve
  • Do this on the side with the black rubber
• Push it in as far as it will go with out forcing it too much
• Trim off the the excess, leaving ~1/4 inch of tubing beyond the end of the tip of the valve

• Take the valve and bit of aquarium tubing and slide it into the piece of 3/8 inch OD tubing
• Don't slide it in all the way yet

• Take the previous assembly and slide it into the piece of 3/8 in ID tubing
  • Do not slide it in all the way yet

• Take a gluegun and run a bead of glue at the joint between the two larger pieces of tubing
  • Before the glues sets, push the pieces together slightly to create a better seal
• Add glue around the edge of the check valve and push the pieces together before the glue dries
  • The tubing should sit against the valve

• Take a piece of aquarium tubing and slide it into one of the tops of the "T"
• Press it in all the way

• Take a piece of aquarium tubing and slide it into the second valve
  • Take care to install the tubing on the correct side -closest to the the black rubber
    • See image for clarification

• Take the T+Tubing assembly and the Tubing+Valve#2 assembly and connect them

• Take the T and Valve #2 assembly and slide the tubing into Valve #1

• Add the long piece of aquarium tubing to the bottom of the "T"
• Install the syringe at the other end of the same tubing

• Take the large end of the tubing and carefully slide it onto the flask's side arm
• Install the funnel
• Add a filter
• Pour in the gum solution of your choice
• Pump the syringe a few times until you achieve a pressure differential
  • It doesn't take much for filtration

• Set up the Miops Splash
• Add the newly prep'd viscous solution
• Have fun with splashes

Check back soon for an Instructable on setting up and using the MIOPS Splash Kit with 2 flashes.