Introduction: Waste Veggie Oil Heater

Picture of Waste Veggie Oil Heater

One of the primary issues with driving a vehicle that runs on waste veggie oil is getting that oil hot. Both in the car and when filtering. Here is a simple/inexpensive way to heat up your oil using only two items - magnet wire (30 gauge) and aluminum tape.

Step 1: Wire Calculations

Picture of Wire Calculations

I am using a 30 gauge red magnet wire obtained from Radio Shack. The resistance of this wire is roughly .26 ohm per foot. We need to do some simple math to figure out how much energy and wire we want to use.

My goal was a heater that was about 60W. Here is the way I calculated it.

20' of wire is has a resistance of 5.19 ohm

12V = (I) 5.19ohm
12 / 5.19 = I = 2.31A

12V * 2.31A = 27.7W

About 20' of wire gives me close to 30W of energy. I ended up using two 20' segments for a total of 60W of power.

Step 2: Aluminum Tape

Picture of Aluminum Tape

I covered part of my veggie oil filter with aluminum tape. The tape is single sided and costs a few dollars per roll. The idea here is to use two layers. One layer of aluminum tape that touches the filter, and another sandwiches the magnet wire between first layer and second. This should help transfer the heat energy more evenly around the filter.

Step 3: Testing the Heater

Picture of Testing the Heater

I hooked up a 12V motorcycle battery to the two leads I added onto the magnet wire ends. It does not matter which is positive or negative. You can see that the temperature is ready nearly 88F at the top of the filter. This is ideal when filtering veggie oil. I will often bring my oil temperature even higher to something like 120F. In the end you should be able to make about eight of these little heat wraps for less than $10.


Stefanovski (author)2014-04-03

Heat from exhaust ? can it be use

jedwardbarker (author)2010-12-10

Great idea; I just completed a 12v heated fuel pickup with this design. But that math is all wrong. 20' of 30 AWG wire has a resistance of 2.064 ohms, then:

E=I x R
12v = I x 2.064 ohms
i = 5.81 amps

I is current, not power. To find power:

P = E x I
P = 12v x 5.81
P = 69.7 watts

So, each of those coils is actually about 70 watts. That's 140 watt heater, not a 60 watt.

sklarm (author)jedwardbarker2010-12-11

The math I'm using is correct and the same as yours. I intentional avoid using charts and actually measure the resistance of the wire.

jedwardbarker (author)sklarm2010-12-11

So there's really that much variance in the resistance?

drinkmorecoffee (author)2008-07-26

I like this idea, I think I'll use it to heat something a little bit larger, though. Like, say, a 55 gallon drum of WVO, to separate all the moisture and gunk from the good oil. I've been playing around with heating oil in carboys, and I can get the maximum amount of oil out of the cloudy stuff that doesn't like to react for biodiesel when I heat it to about 100 degrees F. Cheers! -DMC

sklarm (author)drinkmorecoffee2008-07-26

depending on your location you might be able to paint your drums black and let them sit in the sun. Then use the heater for additional warming on colder days.

drinkmorecoffee (author)sklarm2008-07-26

Actually, that's exactly what we're doing right now. They don't get quite hot enough just sitting in the sun (we have lots of trees, so we only get so much sun in one spot during the day), so this is perfect. What kind of alluminum tape is that? Lowes has 3 or 4 different kinds, one roll is $6, another $8, and a higher grade tape for $16 a roll.

sklarm (author)drinkmorecoffee2008-07-26

I suspect the $6 stuff is just fine for this purpose. If it feels flimsy just do another layer of it. I normally use a 1100W bucket heater in the winter to rapidly heat up my 55 gallon drums for filtering. My tanks get sunshine, but when it is below freezing at night that grease sure gets cold. This same heat wrap could also be used around any unheated filters you have in your grease car. -Mikey

Matt D655 (author)2008-07-17

Can a gas car run on this stuff?

sklarm (author)Matt D6552008-07-17

Waste Vegetable Oil will not work in gas based cars, only diesels.

If you want to make your own fuel for a gas car the only options I know of are:

- ethanol
- methanol
- butanol
- biobutanol

basically different forms of alcohol. Usually a slight conversion is required for ethanol. Methanol, butanol, and biobutanol can all be burned in a gas car without modification. Biobutanol would be the most sustainable. I recommend checking out the algae based distillation method that Patrick Ward used over at

GorillazMiko (author)2008-03-17

Great Instructable, I might show this to my mom if we ever need to do something like this.

thinkahead (author)2008-03-16

Wrapping the magnet wire around an iron bar placed inside the waste veggie oil container and switching the current through it at a selected rate might produce inductive heating that is easier and more efficient to control.

sklarm (author)thinkahead2008-03-17

I like the idea of a modulated heater for better efficiency. Any suggestion about frequency? I have no problem hooking this up to a microcontroller and reed relay for the switching. I just need a frequency to work with. Maybe something low like 10Hz? Great idea!

thinkahead (author)sklarm2008-03-17

Experiment. Start with lowest frequency you can generate then measure temp. Build a frequency to temperature table and then make a chart. Next build a feedback loop using a thermister and controller to keep temperature at maximum or at least constant.

LinuxH4x0r (author)2008-03-16

Couldn't you just use a radiator filled with coolant from the engine? Besides that, great instructable. BTW: What do you use this in? I'm thinking of buying a vw golf tdi, or maybe a jetta. Any suggestions?

sklarm (author)LinuxH4x0r2008-03-16

I use this heater only when obtaining grease. My veggie car is based on the coolant system for its primary heat. As much as I like the coolant heated veg systems (they are great) I find I still need electrical assist on my filters at least on startup.

My car is a '84 Mercedes that I added a Frybrid kit too. I would recommend putting a lot of cash up front into your conversion kit and obtainment pump/filter. They will quickly pay for themselves (probably 2 years for the $5k in grease gear I bought) burning about 150 gallons a month.

The VW TDI's sure look nice. I don't know much about their injectors. I wanted a inexpensive vehicle for my first conversion.

You can see some pics of my conversion and open hardware I've made for it.

LinuxH4x0r (author)sklarm2008-03-16

Do you know about b20? Is it ok to run without converting it? How about b20 in summer, and 100% diesel in winter?

sklarm (author)LinuxH4x0r2008-03-16

Sure you can run B20 down to -5 deg F. B20 is 80% petroleum still so you do not need any modifications. I would recommend a block heater for any diesel that is going to be in a climate where temperatures normally drop below 32F. Depending where you live you could buy B100 in the warmer months. I wouldn't use that below 50F. Full on WVO conversions are really for folks that want to pay nothing for fuel and have the time and resources to take on a pretty serious project. It took me 34 hours spread over a week just for the conversion and that is considered record time for a newby. You will not save any money on the biodiesel front, but you will reduce your own CO2 levels assuming you are not driving across the state for it. Best to just avoid driving/flying as much as possible if you really want to have a impact.

LinuxH4x0r (author)sklarm2008-03-16

I'm in santa fe, NM, But I will probably go to MN alot, so a heater would be good. Does b100 need modification? I don't want to mod it, but I also don't want to ruin it. What is the highest I can run? The place that sells b20 is in town (less than 10 mi away)

sklarm (author)LinuxH4x0r2008-03-16

Santa Fe is pretty damn cold (at least to me). I live 200 miles south of you (TorC) and in a former life was a Linux Admin. If you are going to be several cross country trips to NM to MN you might as well grease it. - Buy a high end two tank veg conversion (Frybrid / Golden Fuel or Custom) - run B20 in your starter/purge tank - run waste grease in a second trunk tank There is a crew in Albuquerque that does full on conversions and claim to have a high end $4k kit + install fee's. I don't know any details. You can call Kevin @ 505-573-0039 . Their price is much higher than any of the other kits so I'm curious what makes it special. Consider my temperature gauge as well. Your veg tank will be a bucket of jelly each night you need to know when your coolant & veg have warmed up before flipping tanks.

LinuxH4x0r (author)sklarm2008-03-16

Thanks! I might just do that. What is the advantage to the high end ones? I was also considering a CNG conversion. What do you think about that?

sklarm (author)LinuxH4x0r2008-03-16

The high end kits use all stainless steel or aluminum. No plastic or copper which has issues with hot veggie oil. The good kits are also coolant based with optional electrical assistance where needed. The filters are normally quite affordable and also heated. In a climate like Santa Fe you will need a high end, none of the $300 kit plastic tank nonsense with manual ball valves to switch. That is strictly bush league. I don't know a whole lot about the CNG's. I suspect you will pay a lot for the propane you will be driving on and a fair bit for the kit/conversion. Even though CNG's will burn cleaner than gas/dinodiesel I don't see them as sustainable since we are running out of Natural Gas faster than any other petroleum resource. Start with just buying a small diesel and buying B20+ from your local coop. If you want to go deeper grease out your diesel. Beware it is a way of life. Nothing is really "free". You will pay for the grease with time.

About This Instructable




Bio: I design and sell two different electronic devices. The first devices desulfates old dying batteries. The second assists people with the fermentation of foods. When ... More »
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