Ask Capt. Gary
Not much is going on in the Q&A department, although it’s but a little bit of time before everyone’s thoughts are going to turn to get their boats ready for spring fishing and the questions that generate. I did get a question at my local, ahem, watering hole, from a gentleman about filters which I said I’d answer, so let me get that out of the way. To be honest, there’s not a lot to be said about filters, beyond “you need them.” To be more specific, however, you need them wherever you have a fluid entering a metal or plastic that could be torn apart by repeated exposure to the odd little bits and pieces that are in usually found in suspension in the fluid. The fluid can be water – fresh or salt – antifreeze, gasoline (and let’s not even talk about the ethanol boondoggle), diesel (and let’s not even talk about biodiesel), or any other liquid you may encounter. And we shan’t forget air, which can really move some chunky material around and into places where you don’t wish said chunks to be. Air Filters Engine air filters are generally designed to scrub large particles of contaminants out of the intake air and do that job admirably well. It’s rare when the lowly air filter even gets thought about, unless it manages to somehow dislodge itself and otherwise rattle around, so it behooves you to ensure you change any filter element when you’re doing all the other change stuff on your engine; i.e., make sure you do it seasonally no matter how clean you think it is. Fuel Filters Fuel filters, on the other hand, are something we all know we have to change and tend to for a variety of reasons on a regular basis. One of the more important reasons is that boat fuel tanks, especially when run light rather than full, tend to condense moisture (heat of day expansion of tank + cool of night contraction of tank = condensation in fuel). This condensation enters the engine feed line with the fuel and is the reason why boats have fuel and water separators located before an inline fuel filter. Since water is heavier than fuel (which is why fuel floats on water) the compartment in a fuel and water separator collects any water out of the fuel and separates some of the other impurities from the mix before passing the fuel on to the inline filter which, theoretically, filters out any remaining impurities. Your job, beyond changing the filters when appropriate, is to drain the water out of the separator compartment. Filters types, beyond being engine specific, are usually expressed as the micron size of the element that does the filtering. But what is a micron? Well, it’s a measurement of size and is equal to one millionth of a meter, one thousandth of a millimeter or 39 millionth of an inch. Human hair runs between 40 and 90 microns in width, which might make more sense for most of us. Regardless, a 10-micron filter; will filter out substances larger than 10 microns. But that would be too easy, right? What a 10-micron filter will do is dependent on how the number was arrived at. Not wishing to muddy the water (ha-ha), there are two methods relevant to consumers that determine filter efficiency. If you see the letters NMR follow by a percentage and a size it means Nominal Micron Rating and states that the filter will capture X percentage of particles of X size. This is a good rating to base decisions on (assuming you can’t find the appropriately part numbered filter for your one-off, 60-year-old diesel). The other rating is called an absolute micron rating (AMR), but all that means is that someone passed a fluid containing specific sizes of glass beads through a single sheet of whatever substance the filter element happens to be made from. Failing finding the appropriate filter based on the engine type I have, I’ll go with the NMR rating. The last thing to note about filters is that they aren’t a mix and match game. Rarely will fuel filters meant for gasoline work with diesel and vice versa. In an emergency, knock yourself out, but otherwise keep water filters for water, diesel filters for diesel, gasoline filters, etc., etc., ad nauseam. Trim-Tilt Problem As usual, I didn’t pull Irish G’bye until January this year, so I’ll have an inordinate amount of work to do to get her ready for spring. An aside: I ran across a trim problem as I was heading — in whiteout conditions on January 28 (thank you Garmin chart plotter) — to the put-in. When I got her up and out on the trailer that was it for the tilt. My initial thought was, “there goes $500,” but after a little thought, I figured maybe it was low on hydraulic fluid. Sure enough. A $6 tube of Yamaha hydraulic fluid and she was as good as new. The fluid reservoir is located on the transom side of the engine and is recognizable by a screw plug. Get the boat as level as possible, insert the refill tube and fill the reservoir. Give the tilt switch a click or two to force any air out and button it back up. One tip: if you are doing this, cut the filler on the hydraulic fluid tube as far to the end as possible. If you cut too far away it won’t fit in the hole where the fluid goes. I ended up using a giant syringe to do the job because I did cut too far from the tip. Meanwhile, as to why I was still in on January 28 … We had to hold our annual New Year’s Day (2018) clamming trip on Christmas Eve 2017 because New Year’s Day’s tide was high at 1000 hours and that wasn’t gonna’ work. We got a nice 1000 low on Christmas Eve and had a good bit of clams for dinner the following day. Of course that was followed by a massive family Christmas dinner, a hangover the next day, then off to the city to take my grandson to SpongeBob Square Pants on Broadway (a good show … I didn’t even nod off) the next day and that was when the Canadian weather showed, freezing Irish G’Bye in her dock. Scallop season was about the best any one’s seen in quite some time. It’s certainly the best I can recall since 2010 … and there’re still scallops out there. The bounty kept the price down a bit, but it should have equalized earnings by the mass of product. Be interesting to find out why it was so good, though … although, I guess one shouldn’t look a gift scallop in the mouth (to mix a metaphor). See ya’ on the water … soon enough.