Air Filter From a Cat Food Can




About: I'm a refugee from Los Angeles, living in backwoods Puerto Rico for about 35 years now and loving it. I built my own home from discarded nylon fishnet and cement.

I recently bought a new-old vehicle and it had no air filter for the carburetor.  My first attempt to find one at the auto parts store failed, so I made my own out of an aluminum cat food can and stainless steel parts from an old coffee maker I found. 

The stainless steel screen from the coffee maker is very fine, although maybe not as fine as a paper filter.   At least it will keep the cockroaches out.   Also, if it ever clogs I can clean it and keep reusing it. 

Step 1: Design Evolution

The design started out with a bunch of round holes drilled in the bottom of the can.  One hole centered the can on the threaded vertical rod of the carburetor.  The next layer was the fine screen.  The top layer was a stainless steel circle from the coffee maker, with round holes in it.   The end result:  the engine choked climbing hills for lack of sufficient air. 

The next improvement was to cut larger holes in the can, using a drill and a nibbler tool (see the next step).   For some reason, I chose to use three holes with three arms.  Before even trying it, though, I noticed the other round part from the coffee maker with four holes. 

I replaced the many-hole round part with the 4-hole round part and cut the can with 4 corresponding holes.  That way the holes line up for more direct air flow. 

Thus far, the car is running fine.  If the air filter ever clogs, I can always just clean it off with detergent and water and keep using it.  There will be no need to ever buy replacement paper filters. 

A nut and spacer washer hold the parts together on the carburetor.  Pressure is around the edge of the can, not in the center. 

Step 2: The Nibbler Tool     This link takes you to a Wikipedia article about the nibbler tool. 

As its name implies, it takes tiny bites out of sheet metal.   When you squeeze the handle, the nibbler jaw closes, nipping of some metal.  You can drill a hole, insert the head of the nibbler, and nibble out a larger hole. 

Nibblers can be found online. 



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    11 Discussions


    7 years ago on Introduction

    try fitting a dried out thick baby wipe over where the screen is.


    7 years ago on Introduction

    Have you tried using the can as an "adapter" for the air cleaner housing. What type of car/carb/engine are you working on. I did not have alot of time to read closely. Sorry!

    1 reply

    Reply 7 years ago on Introduction

    It's an Isuzu Trooper. No, I haven't tried using the can as an adapter.

    Since posting this, I added a PVC plastic cowl over the filter. I'm still aiming to eventually replace it with the original cleaner housing.


    8 years ago on Introduction

    it looks cool but even that fine mesh wont keep out dust which can really hurt your engine, how about trying a coffee filter ? Still be super cheap to replace, Nicely done "ible" and some great pics !

    2 replies

    Reply 8 years ago on Introduction

    Thanks for the idea. I'll consider it. If it's a tighter mesh, I'll probably have to increase the area somehow to keep the same air flow. Anyway, this may not be the perfect air filter, but it helps.


    Reply 7 years ago on Introduction

    You might also try a bit or a stack of that blue heating-and-air-conditioning filter stuff.


    8 years ago on Introduction

    A 5 HP mower engine has an air cleaner about this size. It uses oiled foam as the filtering element.

    But you say this is for a vehicle. What kind of vehicle? If it's a car, have you considered going to the an auto recycling (a/k/a "junk") yard to find the proper filter housing from the same model car?

    You need better filtration for this if you are running any type of internal combustion engine.

    3 replies

    I did get a proper filter housing, but it didn't seat well. Too many mechanics have touched and altered things, I imagine.

    I put the cat food can filter back on and made a PVC cowl for it.

    I'm not giving up on getting the original filter to work. For the moment, the car seems to run well. I don't know if there is enough air for complete combustion of the fuel, but the engine behaves well.

    It would be nice to know how much airborne grit is getting through the stainless steel filter compared to what a paper filter would catch.

    Little or no air resistance with your wire screen, so it should run just fine until it dies an early death due to abrasive dust that goes right through your screen. I think you might have issues if you tried to put a 5hp foam element on your car-sized engine.

    I agree with you. It's better than nothing, but not good enough for the long run. I just have to do some more inventing to get the proper filter to fit.


    8 years ago on Introduction

    I may very well try this to replace the bulky air-box on my '82 Kawasaki KZ650 CSR