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This subject used to be covered under our “Oil Filter Suppressor” page, but we’ve decided to give it the space it deserves.  In addition, we’ve given the “Maglite Suppressor” it’s own page as well.  You may also want to read about the new IMACS – Integrated Muzzle Adapter Coupling System

You may also want to read our page, Books on How to Make a Silencer.

Wix Fuel Filter

Buy a Wix Fuel Filter here:

Wix 24003 Fuel Filter

Wix 24004 Fuel Filter Cartidge

NAPA 4003 Fuel Filter

THREE (3) 3/4 NPT Plug Cap End – Black Nylon Threaded Plug Fits 4003

As we discuss repeatedly, whether making a suppressor from an oil filter, a fuel filter, a flashlight, or anything else, what you really need are two things; 1) A can or tube-like expansion chamber – preferably with some media/baffles in there to absorb the expanding gasses, and 2) a threaded adapter to connect that can or tube-like expansion chamber to your barrel.  The tricky part is always making certain you are matching the right threads for both your barrel and the can you have chosen.  That is where most of us lack the tools and ability – to build our own adapter.  Once you have the right threaded adapter, the rest is probably within the grasp of the average man’s tools and abilities.  We recommend you spend a few minutes researching the threading and materials and looking up some reviews on or elsewhere prior to spending money.  Also, viewing videos on YouTube can be helpful as well.

Well, the Maglite is but one option when you’re looking for a solvent trap or a do-it-yourself suppressor design.  There is a particular model of fuel filter that may be even better than the Maglite at both acting as a solvent trap as functioning as a suppressor.  The Wix Fuel Filter seems to be built almost with functionality as a firearm suppressor in mind.  When you look at this item, both on the outside and at the guts, it looks like it’s begging to be used as a suppressor.  I mean, look at this thing!  It is flat black and sleek looking, lightweight and comes with a replaceable filter media on the inside.

Wix Fuel Filter cartridge

Replaceable Wix Cartridge


The biggest trick for this one is the threaded adapter, which is not as straight forward as the oil filter suppressor or the Maglite suppressor.  The adapter needs to be 3/4 NPT.  These threads are tapered in a slight cone-shape.  Using the wrong adapter here could be anywhere from annoyingly misfitting to disastrous, depending on what use it is put to.

As one Amazon reviewer of a threaded adapter says,

Be careful when Amazon says “frequently bought with…”
This will not work well with a WIX filter.
This is 3/4 x 16
The WIX is 3/4 NPT
They are different threads.

We have identified one supplier that sells these 1/2-28 to 3/4 NPT adapters, and he is sold out.

So once you have your threaded adapter, thus enabling the coupling of your barrel to the Wix Fuel Filter for use as a solvent trap, you’re well on your way.  From there, should you decide to attempt to convert it into a suppressor, it’s a do-it-yourself project and you take all the risks and you are responsible for your own success/injury/jailtime.  Again, we recommend you use the Fuel Filter as a solvent trap only, unless you have met all the ATF’s requirements for manufacturing a suppressor.  Even when using it legally as a solvent trap, you may want to take precautions not to give the appearance of having a the intent to use it as a suppressor.  There is a video that explains how below

We’ve found a few videos on YouTube that may also help with your understanding of how these products can help you recycle your cleaning solvents.  Hat tip to Dustin of for the very informative videos.


Make SURE you get the correct adapter. The Wix Filter needs a 3/4 NPT thread.

There are many vendors selling adapters that they claim will fit the Wix Fuel Filter, but are not the correct thread type so – Caveat Emptor!

We recommend you learn what you can from watching others on YouTube before you go off and try this on your own.  Just pay attention to the law of the land (The ATF/NFA) and the laws of physics.  Running afoul of either of them could give you a really bad day.

Disclaimer – Second Amendment Check, LLC does not recommend breaking the law, and will not be held liable for any injury, damages, or legal trouble individuals may find themselves in.


  1. You’ll need:

    -whatever you barrel thread is to a 3/4 npt adapter
    -The filter (the stick filter cartridge will often not hold up well to weapons chambered over .223)
    -same size ID Freeze plugs with a centering jig so you can have perfectly centered holes (or you can find machined aluminum versions that are a lil more spendy, but higher quality, allowing them to slip in with no play is fine- they do not have to be pressure fit for the unit to work properly)- holes must be exact, you do not want a baffle strike.
    -a spacer tube (slips in between the baffles)
    -eBay sells aftermarket end caps to clean up the look and close up the front so you don’t have the stock gaping hole.
    -research online to the necessary drilling diameter per your caliber used, YouTube is a great resource as well.

    Common sense dictates that if something is loud, then you muffle it as to not disturb yourself and/ or others.

    Party on. Prison would suck, but hey, at least your finally putting your tax dollars to work, and it’s American prison- sleep all day- frat- like atmosphere= cake. You’ll learn far more useful illegal shit while you’re in.


  2. Jesus Christ!!! If you wanna yack start your own TALK SHOW!!!! Just show how it is DONE!!! Most boring Video on the internet!


  3. They make 1/2 ” NPT to 3/4″ NPT reducer in plumbing and electrical fittings.


  4. You beat the ‘dead horse’ unnecessarily. We got it the first two times!


  5. If the filter is 3/4 NPT threads, then you could cut the threads off a 3/4 nipple (found at any lowes or home depot in plumbing aisle) and weld them (TIG weld would be recommended) to a muzzle brake or whatever you have that threads onto your barrel. If you can’t, or don’t know anyone that can weld, ask a plumber or pipefitter what you can use to make the connection. Chances are they have some fittings in their work truck that will work.


    • The people who don’t understand the difference between 3/4 NPT and 3/4 – 16 can’t weld and don’t have a work truck.


  6. I bet of you had a tax stamp and needed to make baffles for the inside you could use a hole saw and the bottom of aerosol cans. The metal is thin enough to shoot through and light enough. In theory


  7. Geez man I mean c’mon like really dude I got it so get it done and c’mon ok please really!!!!!!! If the guy would just stay on target and get the information out and quit pussyfooting around then the video would be about an eigth as long as it is so stop with all the c’mon like really and other superfluous crap and dribble and your done and we’re not falling asleep with our finger sticking in a hole trying to keep solvent from draining out onto the floor (yeah right phhhhhht) (shhhhhh be silent ok) so please get on with it so we can get to work instead of beating our heads on the table wishing you’d hurry the hell up


  8. What is the large socket for? Does that go in place of the spring loaded piece?


  9. It is smaller than I need…


  10. What has to be done to the inside of the filter if in theory it were to be used as a suppressor?


    • Unknown enthusiasts

      In “theory” simply take the guts out with two big wrenches or a bench vise, every piece that doesn’t have a hole big enough for whichever round you choose to shoot through take a table drill and drill the appropriate size holes so that there is no obstruction for the round to go through. Of course that’s just a “theory” with acceptable tax stamps.


  11. Unknown enthusiasts

    So whenever we’re ready to use as a suppressor (with proper tax stamp) you just pop a round through the filter? No drilling?


    • I have heard yes. As long as its a tihin wall. If the end cap is thick metal, i would suggest drilling and making the hole one size larger than 1/4 inch. However, 1/4 will work if you are going for a .223.


    • No. Don’t try it. I did and the round jammed in the suppressor and warped it. Internally, the filter cartridge is held in place with a spring loaded “thing”. You have to take the unit apart (big wrenches at either end) and do some engineering.


  12. How do I get/buy one of those adapters for the wix?


  13. Why are good videos often ruined by poor presentations? That guy’s vocal characteristics make his videos among the most annoying ones I’ve ever seen.


  14. I NEVER manage to watch the video to the END since I always fall asleep.


  15. The 3/4 NPT refers to the Outer Diameter, (male end) that’s what screws into the filter, the inner diameter (female end) screws onto the host barrel which in the case listed above is 1/2 × 28. Attempting to tap the OD would only make matters worse as the ill-fitting threads would be even smaller than they already were to begin with. I wouldn’t recommend using it in that case, as serious injury or worse could occur.


  16. Overexcited Cracker

    If he’d quit it with the “I mean c’mon…” already and got to the point, I would’ve finished the video. Annoying.


  17. where do i get your adapters ???


  18. I fell asleep twice listening to this guy.


  19. Curious. Since it is smaller than the 13/16 thread adapter many have, coukdnt it be safely drilled and tapped for the 13/16 x 16?




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