Conference vmszoo::rc

    John,
    
    Re: bending fuel tubing...first, if the tank doesn't come with it,
    replace all the hard brass tubing with the softer, bendable type.
    this stuff can be easily bent to all but the severest of angles
    without any special tool or technique.  Another thought is to simply
    discard the brass tubing altogether and use copper tubing throughout.
    It's even easier to bend than the bendable brass variety and is
    more maleable...resistant to rupturing at points of stress.
    
    If, in any case, you find it difficult/impossible to accomplish
    the desired bend without kinking/collapsing the tubing, here's a
    little trick I've used successfully over the years: Insert a length
    of solder (as large in diameter as will fit into the tubing I.D.)
    into the tubing, leaving some excess hanging out both ends.  Now
    CAREFULLY bend the tubing to the required angle.  REMEMBER that
    solder is soft and can be deformed if you get heavy-handed, that
    is; you can STILL kink/collapse the tubing if you don't exercise
    caution.  Try bending around a hard round object of appropriate
    diameter (drill bits work well and provide a wide variety of sizes)
    and keep in mind that a shrp, 90-degree bend is virtually impossible
    to accomplish under ANY circumstance.  The larger the radius of
    the bend can be kept, the better (easier)!   Now, pull the solder
    out of the tubing...be GENTLE as you can break the solder off inside
    the tubing.  If this should happen (or if the bend is too tight
    to allow removal of the solder), simply heat the tubing with your
    soldering iron and melt the solder out.  A quick rinse with isopropyl
    (bathroom) alcohol or acetone will remove any flux residue from
    the inside of the tubing and yer' all set.
    
    Adios,	Al

    John,
    
    Another thought on bending fuel tubing: someone makes a set 
    of tubing benders...it "may" be K&S (or is it KS?), the people 
    who make all the different types of brass/copper/aluminum tubing.
    They consist of a tightly wound coil-spring, flared at both ends.
    The principle is that, by inserting the tubing to be bent into the
    approprate sized spring, you can bend without kinking/collapsing
    as the spring supports the circumference of the tubing completely
    around the O.D.  I haven't used these, or seen them used but they
    just might work.
    
    Al

RE: .16

    I have a set of the K&S tubing benders and they work pretty good.
    Like everything else though, they aren't "magic" and the tubing
    will kink if you try to bend it too sharply (removing kinked tubing
    that has locked itself to the inside of one of these is no fun either).

    I can't say which is better as i've never tried the solder method.
    The only clear advantage that I can see to the benders is that they come in
    a wider variety of sizes than solder does.

    GES

Geez, seems like we've created a substantial side topic here...my
apologies to the originator of this note.

I used a piece of copper wire, about 14 gauge, to do some bends
(not the one in the vent).  That seemed to work pretty good, tho
I think the inside diameter of the tube is closer to #10 or #12.
I did get a little kinking with the #14 wire.  That's a sharp
bend that you have to make there; going from the filler cap up to
the little bubble at the top.  Wonder why the manufacturers dont
move the bubble back a little.

As far as using solder is concerned, all the stuff I have is for
electronics and is much too small diameter to support the inside
of the tube.  Probably one would need the stuff used for copper
plumbing to do the job right.

I'm going to try to make a "for real" bender, like a conduit
bender, out of aluminum or a hard wood (I have some ebony
around).  If it works, I'll let y'all know.

    John, Why bother? Harry Higley markets just such a bended for tubing.
    It's made from alum hex stock with a rounded channel milled in it.
    I think they're only a couple of bucks. I have the springs and the
    HH bender. Both work OK.
    
    						Tom

    
    		If the solder you use like I do is for electronics and
    	very thin why not just fill the tube with melted solder by
    	heating the tube and adding solder to fill it using a piece
    	of masking tape over bottom end. Let it cool and solidify,
    	make the bend then heat it up and let the solder flow out.
    	All that left is to clean with flux solvent.
    
    
    				Mike
    

    I have used salt to put tight radius bends into 1/8th ID rigid plastic
    tubing (with heat) and the brass tubing of similar size use for
    fuel tanks.  The technique, for those who haven't tried it, is at
    the end of this note.  I was not entirely happy with it; it worked
    better with the plastic because I could really soften the outside
    of the bend.  My bends for the Kadet fuel system were of low quality.
    
    I just bought the same coils that John bought, but I haven't tried
    them.  I have used this technique on large tubing, and I, too, had
    difficulty getting the spring off the finished shape.
    
    I've read somewhere (maybe in this conference) of using lead solder to
    fill the tubing before bending it.  That sounds neat for tubing sizes
    that match the available solders.  Has anyone out there tried using
    pully-shaped forms for bending small lines?  

    The salt technique is a variation on an old technique based on sand.
    The idea is to fill the tubing with something that will not crush
    but will be easy to remove after bending.  Sand will take the extreme
    heat of a torch on a large pipe.  I use salt so I can be certain
    of getting it all out later; salt can be rinsed out.

    The idea of using solder is you melt the solder into the tube!
    You just don't slide it in, you fill it up!
    
    -Bill
    

    re  the solder in the tube
    
    Do you then use a torch on the outside of the bend if it is not
    near an end?  

Pulley shaped forms:

Another variant on this idea is buy several large bolts and washers
Pick a bolt of the correct size to match the radius of the bend you want
and sandwich your tubing between 2 washers and mount the thing
on your vice and bend around. 

I saw this in some RC tips section and haven't used it yet myself.
I also have the set of springs - but I think I'll get some nuts and bolts
next time I'm at the hardware store.

Bye          --+--
Kay R. Fisher  |
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    I've had a set of the spring type benders for a couple of years.
    They work great.  The Air conditioning mechanics use these all the
    time to form copper tubing.  If you rotate the spring, it will come
    off fairly easily.  You can also put a little oil on the tubing
    before bending to help with removal.  I highly recommend this tool
    to anyone who sets up fuel systems.  You get perfect bends without
    crimping every time.  It saves time and aggrivation.  Don't work
    this tubing too much or it will crack.  Also, be careful not to
    have a situation where engine vibration can cause it to crack. 
    I use silicone to seal the tubing going through the firewall instead
    of someting solid like epoxy for this reason.  I had the tubing
    crack once and leak inside the fuse.  I don't usually run the brass
    tubing through the firewall at all now.  I terminate it inside and
    run the flexable silicone tubing through.  This had a disadvantage
    that it requires removal of the tank to replace the tubing but I
    have had less trouble with this method.
    
    Charlie