Conference vmszoo::rc

    I quess this is as good a place as any to have a discussion on fuel
    filters......
    
    
    
    
    Statement.....	I don't use a fuel filter on the airplane.
    		Feel they cause more problems than they solve.
    
    
    What I do, do rather is;
    
    			1, Flush all new tanks prior to assembly.
    			2, Use the new tank once assembled on a test
    stand
    			3, Filter fuel entering the tank.
    
    It took me about two years to come up with this system. And I can
    say that it works. I can't remember that last time I field cleaned
    a carb.
    
    			Oh, one other suggestion. Purchase some paint
    strainers and use one when your pouring fuel from a new gallon into
    the fuel container on your flight box. 
    
    
    
    Tom

    If you have a klunk in your fuel can and an in-line filter in your
    pump line, that is usually sufficient, but you're right, by pushing
    the fuel into your on-board fuel tank, you *ARE* risking some
    possibility of trash on the *WRONG* side of the on-board klunk.
    This, however, is how most folks do it.  You can use the third hole
    in the on-board tank stopper, but you have to put a plug of some
    sort in the end after you add fuel thru this third line.
    
    If you really want to spend some bucks ($), you can look into the
    DuBro Qwick Fill.  This is a really slick method, but, like I say,
    $$!!!!!
    
    Chuck
    

    On a related issue, are there vendors who do the tank plumbing for
    a fee?
    
    After three installations, fuel tank plumbing is NOT my favorite
    pastime.  I have the Sullivan(?) set of tubing benders, and I have used
    the Casey solder-in-the-tube technique with some success, but I still
    have an intense dislike for this task.  Someone with experience and an
    extensive set of really proper tools and jigs could do these
    installations a dime a dozen and charge a lot more.  Part of the
    problem is the trial-and-error aspect of doing only a few.  Part
    is my lack of experience, having done this so few times.  Part is
    the expense of building a good tubing bender for this small tubing.
    
    Alton, the tormented tiny tubing twister 

    Al,
    
    You might want to look into the Hayes (formerly Kraft-Hayes) line
    of fuel tanks.  This type is a square tank with a "toe" at the bottom
    front of it to prevent its sliding forward, pinching off the fuel
    line(s).  This is probably the easiest tank in the world to rig
    as it requires no brass tubing bending, in fact it uses no brass
    tubing whatever.  You simply attach the clunk tubing to the nipple 
    on the back of the stopper, insert stopper in tank and secure with a 
    metal compression ring...all hand installed.  overflow and/or fill 
    line(s) are nipples molded into the front of the tank and you simply 
    drill through the nipple to open it, attach silicone tubing and yer' 
    done.  DuBro makes a similar looking tank but I'm not certain whether
    it uses the same plumbing scheme or not...check it out.
    
    I personally prefer the Sullivan tank and have encountered little
    difficulty shaping the bendable, soft brass tubing supplied with
    them.  Another alternative might be to simply substitute same dia.
    copper tubing for the brass...you can make a pretzle outa' that
    stuff without kinking it! 

      |
      | |      00	 Adios,      Al
    |_|_|      ( >o
      |    Z__(O_\_	(The Desert Rat)

    I'll check out the Hayes and DuBro tanks today if Tom's in Chelmsford
    carries them.  I'm not very proud of the workmanship that I have
    just finished.  Thanks for the tip.
    
    Because I have never heard of a vendor for this service and because
    it seems to be only this beginner doing the grumping, I conclude
    that this operation will become trivial after more experience.
    
    Alton who won't need to do this for his Gentle Lady

    Back to the original question...

    I have MY way of doing it which of course is better than anybody
    else's way, although not everybody will agree with me which shows
    their lack of insight :-)

    I use an in-line filter between the tank and carb. I tried to do
    without it on my Super Sportster 20 because there isn't much room,
    and got burned eventually when I got some crap into the needle valve.
    It took me a few days to diagnose and fix the problem, and fortunately
    the engine quitting in mid-flight was always at a place I could bring
    the plane back to the field, rather than dropping it in the woods
    or the Royal Indian Swamp. I use a filter now.

    There are 3 ways to use the in-line filter without back-flushing it
    while filling, which I recommend against for the reasons stated (you
    can get crap on the carb side of the filter which will then wash
    right back into the carb).

    1. If there is room, leave enough of a loop in the fuel line-filter
    connection to disconnect the line BEHIND (tank side) the filter
    while filling. This is how I do it on both of my Super Sportsters
    and my Kavalier. That way, the in-line filter only gets fuel in
    one direction always - toward the carb. The SS-20 is very tight but
    I use a "crap-trap" filter, which is a clear plastic tube with fittings
    on both ends that is slightly flexible and wraps around the cylinder
    just enough to make it fit.

    2. Use a 3rd fuel line into the tank for filling. I did this on my Kadet
    which had a cowl that I wanted to keep the fuel line inside. I added a
    3rd fuel line which I connected to another clunk inside the tank (it can
    be a short clunk, it doesn't have to be able to flop around, just rest
    on the bottom of the tank). I did all my fueling/defueling with this 3rd
    line and stuck a screw in it to block it off after fueling. On the
    Kadet, this was fairly elegant because I routed the 3rd line through a
    small hole in the bottom of the cowl, it stuck out about an inch and the
    carb line and filter were entirely inside the cowl. 

    3. Use one of the filler valves available on the market. I've never
    used these, and I've heard reports that they work good and other reports
    that they are unreliable, leaking fuel and/or air. They're also
    more expensive than I think they're worth. They go in-line, between
    the in-line filter and the tank, and have an external fitting for
    fueling.

    I recommend approach #1 for the PT40, the engine is pretty much out in
    the open and there should be room to fit the filter.

    Another thought - the Kavalier also has a cowl and it was hard to fish
    out the fuel line. In addition, the filter vibrated against the engine
    mount and I thought it might wear a hole in the filter. So, I glued a
    small block of balsa to the side of the engine mount with a hole in it
    that snugly fits the filter. It holds it in place and keeps it from
    rubbing on anything, and is out of sight behind the cowl.

    I also keep a filter in-line in the fuel fill line from my flight box.
    If you want to be doubly safe you could make that filter removable
    and reverse it for fueling/defueling, but I don't bother.

    Dave Hughes

    
    RE: .-1
    I used method #1 on two of my planes and don't find it at all
    inconvenient to unplug the fuel line at the rear of the filter
    to refuel.  It's my favorite because it's simple.
    
    If you decide to use a refueling valve I'd avoid the plastic one
    that you twist 90 degrees to fuel up (don't recall the name of it)
    The one I had didn't last very long.  I like the aluminum one with
    a thing you plug in to refill (Kwik-fill???) but I heard Ajai recently
    had a problem with his sticking open, preventing fuel flow to his
    engine.   I still think it's a better design than the plastic one.
    
    Here's a fourth suggestion to add to Dave's first three.  Use
    a refueling valve, but feed it to the third line into the tank and
    block off the unused side.  Then you don't need to plug the open
    end after you refuel and you don't have to worry about the valve
    failing and causing engine trouble. 
    
    Bill

    Most Pattern birds use   NO IN LINE FUEL FILTERS OR PRESSURE LINE
    FILTERS.
    
    Rather the tank is cleaned prior to installation with fuel and in
    lost cases used on a test stand. Then a fuel filter is installed
    between the fuel tank on the flight box and the filler tube. This
    way clean fuel goes in. Exhaust residue from pressurizing the tank
    is spent fuel and oil. This mixes with the new fuel and isn't a
    factor. 
    
    Make sure the tank is clean and what goes in the tank is clean and
    your all set.
    
    
    
    Tom

    I have been using Tom's method.  I have never had a filter in a plane
    until just recently on my OS120 pumper.  I have a filter on my fuel
    filler line and this has worked fine for me.  If I have a question
    about my fuel being contaminated, I chuck it out.  I very rarely have
    had engine problems using this technique.  I am not against putting a
    fuel filter on board the plans, I just have not found it necessary.  It
    is VERY important to clean the tank before installing it.  Little
    flakes of plastic are in there waiting to clog your engine.  These
    flakes are invisible devils.  I blow my tanks out with compressed air
    right before installing the stopper.
    
    Charlie