Mr. Funnel - A Shameless Plug (and I Don’t regret It)
Mr. Funnel solves a very important problem for sailors and boaters - “What do I do when I have water contaminating my gasoline?”. Normally the answer to this question would be “Dispose of it responsibly”. In an emergency, this isn’t always an option when you don’t have more gas on hand. Mr. Funnel provides an alternative, mobile solution: filter the water out.
Normally I approach products, especially ones that make big promises, skeptically. There’s a bunch of snake oil of all kind of types and flavors out there, especially in the consumer gasoline/fuel additives market (check out our post on the gasoline fuel additive that doesn’t suck and look at the videos that test ethanol fuel additives that deliver all kinds of failed results, or do nothing).
Every once in a while, I come across a product that’s kind of magical for sailors, and boaters at large. These are the kinds of products I love, and this is one of them. Buy one or two or three and stash them in your car, your boat, your garage. They’re just so handy and can seriously save you in a pinch. There are a variety of different sizes, the smallest can be stowed just about anywhere.
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Resources
Eliminator Performance - Testing the Mr. Funnel: https://www.youtube.com/watch?v=p1aJoohWNms
Steiger 256 - Mr. Funnel. Does it Work? https://www.youtube.com/watch?v=pZnt4n-f3n8
Mr. Funnel Home: https://www.mrfunnel.com/Mr._Funnel/Home.html
Understanding the hyrophobic properties of PTFE: https://ptfe-machinery.com/understanding-the-hydrophobic-properties-of-ptfe/
How Does Mr. Funnel Work?
The operating principle behind these fuel/water separating filter funnels is very simple. A screen (or two) located in the funnel provides a surface that can pass gasoline and diesel fuel, but cannot pass water. That seems like magic, but it’s not. The screen doesn’t filter based on size, but works on charge at the molecular level. The PTFE-coated screen uses the bipolar-charged nature of water molecules to repel them, while allowing fuel to pass through. It’s a dead-nuts simple tool that just works, and in my experience, it works very, very well.
There are three common sizes of Mr. Funnel available that, I think, are applicable to boaters.
AF1CB (3.5” Dia x 6” H), Filters 2.5 gal/minute: https://amzn.to/3RVLNW5 (Small enough to stow in your dinghy, but will take a couple painful minutes to filter 5 gallons of fuel)
AF3CB (5.5” Dia x 9” H), Filters 3.5 gal/minute: https://amzn.to/3to1P1D (Small enough to stow in any reasonable size locker in your sailboat)
AF8CB (8.5” Dia x 10” H), Filters 5 gal/minute: https://amzn.to/47jSq8V (Small enough to stow in any fairly large size sailboat locker)
The AF15CB is also available, but is more geared to home and commercial use. It’s a little big to store on your average sailboat.
I would recommend picking up the largest funnel you can stow. The bigger the funnel, the less time you spend manhandling heavy fuel containers. Also, the larger funnels have a bigger sump for water collection, making the funnel a lot more user friendly.
If you are keeping Mr. Funnel on board your small boat or dinghy, I recommend that you stow it with some kind of container that you can use to store filtered gasoline in (such as an empty 1-gallon milk carton or clean bucket). Mr. Funnel won’t do you a lot of good if you don’t have a separate container to filter into. Additionally, since Mr. Funnel always leaves a little bit of contaminated fuel behind inside the funnel, as well as the water you have filtered out, you will want to have a separate container to store the remnants of each filtering session in for safe keeping. Restore the fuel back to an approved fuel container as soon as possible to prevent leaks and/or hazards from improperly stored fuel. You could also get away with a small, fuel-rated hand pump, squeeze pump (Amazon affiliate link), or jig siphon pump (West Marine affiliate link) in lieu of an extra container (but you will still need one to carry the contaminated fuel remnants in after filtering!). Pump the fuel from the container into Mr. Funnel and allow Mr. Funnel to drain back into the fuel tank. Make sure to dispose of any fuel/water remnant responsibly!
On a side note…
I’m a big fan of these West Marine Jig Siphon Pumps (affiliate link) for moving quantities of all kinds of fuel around. They are easy to stow and are simple to use. A static-free (for safety) hose is attached to a brass check-valve assembly. Submerse the check valve into the fuel and make sure the fuel’s destination is lower than the source so that a siphon can work. Jiggle the check-valve to start a siphon. Harbor Freight offers a similar product, but, speaking from experience, I would strongly recommend that you pay the few extra dollars for the West Marine brand. The Harbor Freight version’s hose is difficult to work with (it tends to collapse in on itself), and the check-valve eventually fell off.
