Do you vacuum pack food or cook sous-vide? Then I am sure that you have experienced flooding your sealer with too much liquid. More often than not the machine quits when liquid enter its internal workings including the vacuum pump and vacuum sensor. In this Instructable I will show you:

1) how to clean up a gummed up vacuum sealer

2) how to add a liquid trap/filter to avoid this problem

3) how to disable the internal vacuum sensor, which for me is useless.

First a bit about choosing a vacuum sealer. I have gone through half a dozen units including the fancy intelligent FoodSaver with wet and dry settings and all kinds of automatic functions. My favorite is the lowly FoodSaver FM2000-033 manual machine: it is faster, simpler and cheaper than all the others. Importantly you can manually override the vacuum sensor that triggers the heat sealer. Why would you want to do this? Because this automatic function often does not work; for example 1) when sealing liquid food the machine will completely empty your bag of food and get all gummed with liquid without ever achieving the vacuum it thinks it needs; 2) when packing hot food the higher vapor pressure of hot water will prevent forming the vacuum the machine thinks it needs and the pump will go on forever until it burns up. With very little practice you learn to press the red "seal" button when you know all the air has been sucked out of your bag without relying on the vacuum sensor.

Step 1: What You Need

You need to start with a vacuum sealer in the style of a FoodSaver or Seal-a-Meal. If you have one that has flooded with liquid and stopped working then great: the guaranty is already voided and you do not need to worry about voiding it again with the modification I will show you. I am using a FoodSaver FM2000-033, but the proceedure can be adjusted to most machines.

You will also need the following readily availabe materials and tools:

A small Philips screw driver
Mason jar with a lid
1/4" FIPS to 1/8" ID barb brass fitting
1/4" MIPS to 1/8" ID barb brass fitting
1/4" by 2" pipe brass nipple
24" of 1/4" plastic tube of the type use to connect ice makers. The inside diameter is close to 1/8".
all purpose silicone sealant
electric drill with a 1/2" (12mm) bit and a 3/16"(5mm) bit (not shown)

If you need to clean the guts of your vacuum sealer you will also need:

a seringe
a bowl of warm water
methyl hydrate
a few drop of oil
plenty of paper towels to clean up the mess.

Step 2: Disasembling and Cleaning the Guts of Your Vacuum Sealer

In my model there are five screws underneath the unit that need to be removed for disassembly. Check under rubber feet of your unit for possible attachment screws.
Then delicately pry out the bottom shell of your unit (second picture)
With the guts exposed identify the pump inlet, outlet, vacuum sensor, exhaust port, suction port and vacuum release valve and the connecting hoses (third picture).
Disassemble the hoses from all the ports.

If the internal workings of of your machine are clean and working properly proceed to "building a liquid trap for your vacuum sealer" otherwise continue below.

DANGER: To clean the pump and vacuum sensor you will need to run the pump and this requires you to plug the unit in while it is open. Be careful and only connect the unit when you need to run the pump, ensuring that there is no stray water or wires.

Dismantle the pump from its mount (fourth picture)
Clean all the hoses by running warm water through them.
Dunk the pump head with the inlet and outlet ports in a bowl of clean warm water, keeping the wiring away from the water (fifth picture). Plug the unit in and press the vacuum activation button. You must hold the vacuum pump with your other hand while doing this otherwise it will jiggle all over the place. The pump will suck in water from the inlet and squirt it out through the outlet. With your free hand undo the cover latch to stop the pump.
Throw away the dirty water, replace it with clean warm water and repeat the previous step until the water comes out clean.
Use a syringe to squirt water into the vacuum sensor (sixth picture); carefully sponge up the excess water with a paper towel and then connect the sensor port with the inlet of the pump (seventh picture).
Turn the pump on to suck out any gunk from the sensor.
Repeat the above two steps until the water sucked out by the pump is clear.
Rinse the sensor one last time with the syringe filed with methyl hydrate and suck it out with the pump.
Give the pump one last rinse with clean methyl hydrate in the bowl instead of water.
Lastly put a coupe drops of oil in the pump inlet port before reassembling it into the case (last picture)

Step 3: Building a Liquid Trap for Your Vacuum Sealer

Instructions below us a plastic lid, to supercharge your vacuum sealer see a following step on "Going Over the Top"

Drill two holes in the plastic Mason jar cover with a 1/2" bit (first picture). Be slow and apply light pressure to avoid cracking the plastic.
Smear silicone sealant around one of the holes (picture two) and screw in the MIPS fitting from the top of the lid (picture three).
Screw the nipple into the other hole from the bottom of the lid (picture four).
Smear silicone sealant around the FIPS fitting and screw it into the protuding part of the nipple on top of the lid (picture five).
You may need to unscrew the nipple so that the bottom of the FIPS fitting rests firmly onto the lid surface and is sealed with silicone (picture 6)
Screw the lit onto your Mason jar and you have a liquid trap (picture seven).

Step 4: Adding Water Trap Connections to Your Vacuum Sealer

Drill two holes with a 3/16" drill bit into the cover of your vacuum sealer (picture one)
Squeeze two pieces of plastic tubing through these holes and connect one tube directly to the suction port of your machine (picture two) this tube will be connected to the side of the water trap with the nipple fitting.
Connect the other plastic tube to the pump inlet and the vacuum release valve using a T fitting (pictures three and four).
Connect the exhaust port as it was before (picture five).
You will have some pieces left (picture six). It you want to keep your vacuum sensor you can use the T fitting and a piece of hose to attach it to the intake side of the pump.
Reassemble the vacuum sealer shell (picture seven) and you are ready to use your new and improved vacuum sealer.

Step 5: Going Over the Top

After some use, I found that the plastic Mason jar cover did not keep a reliable seal on the jar so I reconstructed the liquid trap with a disposable Mason snap cover. This works way better and in this context you do not need to dispose of it after each use. It will work for a very long time, and it you find that it fails, just make another one. The fabrication instructions are essentially the same as with the plastic cap, but I would recommend a step drill bit for making wholes in the thin cap.

My second modifications consists of adding a vacuum gauge to the liquid trap. I have used the a gauge available on Amazon.com for less than $6. It works great. Just tap a whole of the required diameter into the cover and liberally apply silicon sealant before screwing in the gauge.

Hey! the FoodSaver unit can attain a vacuum of about -24 inch Hg or -80 KPa which I consider very respectable (80% of full vacuum).. If the material you are sealing is at a temperature of 60 C or more you can achieve a vacuum above the partial pressure of water. This means that all air will be effectively evacuated and replaced by water vapor. When your bag is cooled to room temperature this means almost complete vacuum.

Step 6: Using Your Improved Vacuum Sealer

Your vacuum sealer can be operated with or without the liquid trap. For dry ingredients this is much faster to achieve a vacuum if the trap is removed and the hoses short circuited as shown in picture one. Set your bag of material in the usual way, close the cover and press the vacuum button. When you hear the vacuum pump straining, maximum vacuum has reached and you can press the seal button. If you which to compress an ingredient, water-melon for example, you can leave the pump going until the desired compression is reached and then press the seal button (you can only do this if you have disabled the vacuum sensor).

For wet ingredients you can connect the liquid trap with a Mason jar of a size you choose. Larger jars have more overflow capacity but will take longer to evacuate. In practice I find that the smallest jars work just fine. Connect the hose that corresponds to the machines suction port to the side of the trap with the nipple pipe, and connect the remaining hose to the other trap connection. Set your bag as usual, close the cover and press the vacuum button. You will see the liquid level slowly rise in the bag. After all the air has disappeared from the visible part of the bag let the vacuum run another 15 seconds or so, to ensure all air is evacuated, then press the seal button (picture two). With practice you will know exactly how long to wait to get rid of all air bubbles in your bag. Press the seal button or otherwise stop the vacuum if you see any liquid entering the trap.

Use the liquid catching trough that come with your unit whether or not using the external liquid trap. Check it and empty is when needed. Also empty the liquid trap it it fills above the bottom of the nipple fitting.

With wet ingredients it helps setting the machine and bag on an inclined surface as shown in picture three.