Food Dehydrator (Biltong Kas)
Well this project came into life not because I planned it, but because of circumstances. Our neighbours, two doors from us, placed a fridge/freezer combination on the curb for rubbish collection a few months ago, and yes, the stingy bastard I am, thought I could fix this and resell it or use it myself. I had a fifty fifty chance of fixing the fridge, either the thermostat was busted (easy and cheap to fix), or the compressor was busted (too expensive to fix). Well as it turned out, it was the compressor.
So now I was stuck with a piece of rubbish a few weeks before we move. My wife was fuming because we had no means of disposing of it and I was too proud to put it back on the curb for rubbish collection. (I wanted my neighbours to think I fixed it! LOL) After a few days of deeeeeep thought, I came up with the idea of a food dehydrator. Yes, I saw a few of these conversions on the internet before and thought, well, I do have a food dehydrator, but it was small, now I have the chance of building a nice big one with loads of space for a lot of food to process!!!
Now, as a South African, we love Biltong (almost like Jerky but differently prepared) and Droëwors (dried sausage). This dehydrator is perfect for me to make my own Biltong and Droëwors on a bit of a larger scale. Also, living in Australia, it is difficult to get hold of Biltong and Droëwors and, IT IS BLOODY EXPENSIVE going at $60 a kilo!!!! So naturally, remember what I said about being a stingy bastard, I am making my own at a fraction of the cost.
Step 1: Bill of materials (BOM)
This conversion is pretty straight forward and I cannot give you exactly a list of materials to be used. To be fair, I will give a list but it may vary depending on the type of container you are modifying.
- A few pieces of timber for the door frame
- MDF (9mm) for the door and frame around the fan and air inlet
- Various screws
- Fly screen
- Computer fans (at least 3) or a big extractor fan
- 2 lamp holders (optional)
- 2 75 watt globes (optional)
- 3 electrical switches (optional)
- 12v transformer for computer fans (not necessary if you use a 220v extractor fan)
- Electrical wire
The tools you will need is your basic workshop tools
- Preferably a rotary cutting tool
- Screw drivers
- Mitre box or saw
- Side cutter
Please note that both these lists might not be entirely complete and you might need some other tools and materials but I know that is not a problem because we are all makers after all!!
Step 2: Rip it apart! Cut it out!
The first thing you would want to do is remove the compressor, thermostat, light and doors of the fridge. Be careful when removing the compressor, the gas is still under pressure and might catch you of-guard. Do this in a well ventilated area and use the necessary protection for yourself.
The next thing I did was remove the divider between the fridge and freezer parts. I used a rotary tool and an iron saw blade to do this.
The holes for fans was carefully measured and cut out with a rotary tool. I removed the insulating material with a screw driver. This was a bit messy. Be aware that when cutting out the holes, there might be some copper piping underneath the sheet metal that will also need to be cut.
As you can see from the photos, this part of the conversion is very messy. As I said previously, please wear appropriate protection for the job at hand.
Step 3: Cover uglynes and make pretty!
I used 6mm MDF to cover the unsightly parts where I removed the divider between the fridge and freezer. I used some screws and wood glue to get these panels on.
I used my electric hand sander to roughen up the paint on the fridge in preparation for the spray job. Using mat black spray paint turned out to be really good looking and with the texture of the sanded paint it looks really well.
All of us know that preparation before you paint is very important and I am not going to go into that subject. Again, please wear the necessary protection for the job at hand.
Step 4: Build the door and decorate!
Next I constructed a frame for the door after some careful measurements. It is fairly important to get the measurements correct because it will make fitting the hinges and latches so much easier.
At the bottom of the door there is an air inlet covered with fly screen. At the top of the door I added an inspection window (optional) that I covered with the plexi-glass of the fridges vegetable drawer.
I primed and sprayed the door the same colour as the fridge and asked my 2 boys to make a stencil on the computer with a name for the box. They cut out the stencil and sprayed the name of the box in silver. For those of you that do not know what ‘Vleis Kas’ means, it is Afrikaans for ‘Meat Box’.
Step 5: Hang the door and fit the fans!
Next thing to do is to fit the fans and cover them with fly screen. I made a fly screen frame from 6mm MDF and simply screwed it on to a piece of fly screen over the fans. Wire up the fans and drill a hole at the back to feed the connecting wire through. Hook it up to the 12V tranformer and test.
WARNING: ELECTRICITY IS DANGEROUS. IT CAN KILL YOU. IF YOU DON’T KNOW HOW TO DO THIS, ASK SOMEONE THAT DOES. I CANNOT AND WILL NOT TAKE RESPONSIBILITY IF YOU GET HURT OR KILL YOURSELF.
Next I hanged the door and added the latches. When attaching the latches, make sure they pull the door nice and tight against the fridge as you do not want any gaps where insects and flies can enter the dehydrator. You can also add a foam seal for the door to be sure it seal well.
Step 6: Result and conclusion.
Now you have a functional dehydrator. Fire up the fans and hang some Biltong. You can also dehydrate fruit in this dehydrator. Apple rings sprinkled with lemon juice is a great tasting treat.
As you can see from the pictures, I placed 2 aluminium containers at the bottom to catch any fluids falling down.
In this build I have not yet added the 2 75 watt globes. I added those later because the dehydrator was not that effective. The globes simply dry out the air a bit more and that helps to dehydrate the food a bit quicker. If you don’t live near the coast or where the humidity is low, you will most probably not need to install globes.
I also left out the installation of the globes in this Instructable, because again, it is working with 220V AC, and that is dangerous if you do not know what you are doing.