Conference vmszoo::rc

    Sounds like a cold solder joint to me.  If you had a good joint,
    it would never have broken (unless the joint was allowed to flex,
    solder does not retain its strength when flexed).  Try it again,
    but this time, heat the brass fitting until the solder melts when
    it touches the brass.  Do not use the Iron to melt the solder.
    This should give you a reliable solder joint that'll never break.

    BRAIN
     JUST A QUICK COMMENT I HOPE YOU USED SILVER SOLDER TO SOLDER THE
    JOINT.I HAVE FOUND THAT REGULAR SOLDER DOES NOT STICK TO THE TYPE
    OF WIRE USED IN THESE AIRPLANES ALL THOUGH IT STICKS TO BRASS FINE.
     I'VE ALSO BEEN FLYING THE KAVELIER FOR A WHILE NOW AND THINK IT'S
    A GREAT PLANE.
    
    
                                               KEEP'EM FLYING
                                               JERRY

    I found I had to pre-tin the cables before they would solder well
    to the brass fittings.  There is some sort of grease on the cables
    that must be burned off by a generous application of heat and solder
    (I used normal lead/tin rosin core stuff).  You can test for proper
    tinning by using Randy's suggestion.  Touch the solder to the heated
    cable and note that the solder melts and flows smoothly around the small
    wires of the cable. Don't worry too much about the brass fitting,
    it takes solder well with no special preparation.
    
    Ed
    

    I'll agree that the Sta-Brite variety of [so called] silver solder
    may be a little easier to use on music wire-to-brass type joints
    but don't be fooled...this _IS_NOT_ silver solder.  Silver solder
    requires a torch to attain the high temperature necessary for making
    a joint.  The Sta-Brite ilk of solder is pretty much an un-fluxed,
    tin-lead solder with a small percentage of silver in it.  Yes, its
    somewhat stronger ( and a lot more expensive) than conventional [say] 
    60-40, rosin-core, tin lead solder but I highly disagree with the
    notion  that the latter doesn't work, and work well, in our modeling
    applications.
    
    I've never, repeat NEVER, had a conventional tin-lead solder joint
    fail in over 25-years of R/C building/flying.  But, as was mentioned,
    proper soldering technique _must_ be employed or you do, indeed,
    risk failure of a solder joint.  It's well worth one's time to take
    a course or self-teach oneself how to solder correctly.  In our
    case, it could very well save an investment of hundreds of dollars
    and a like number of hours!!!
    
    NOTE: THE FOLLOWING APPLIES TO STA-BRITE AS WELL AS TIN-LEAD SOLDERING.
    -----------------------------------------------------------------------
    
     The first/foremost requirement for proper soldering is cleanliness;
    the music wire to be soldered _must_ be cleaned of all dirt and
    [finger] oil/grease.  I use fine sandpaper to remove surface oxidation,
    dirt. oilt. etc from the wire then wipe it down with Isopropyl Alcohol
    to finish.  Wherever/whenever possible, brass parts receive the
    same treatment.  Wire-to-wire joints, like landing gear, cabane
    struts, etc. are bound together using fine copper wire, making the
    wraps as tight and as close together as is possible.  I measure
    the depth of the chamber into which the wire is inserted in a brass 
    threaded coupler and drill a minute hole from one side [only] of the
    coupler into the base of this chamber. This is to provide a place
    for excess solder to exit, giving a visual indication that solder
    has sweated the entire depth of the chamber.
    
    OK, assuming all necessary scrubbing, cleaning, binding, etc. has
    been done and it's time to actually solder.  NOTE that, if not using
    Sta-Brite solder, _use_rosin-core_solder_ONLY_!!!  The next most
    important necessity for proper soldering is _CORRECT_HEAT_.  An
    Ungar-type soldering pen is NOT going to be adequate for soldering
    together a landing gear assembly.  Even some of the 2 and 3-wattage
    soldering guns do not have high enough wattage for these heavier
    tasks.  I have a cheap, wooden-handled, heavy-duty, hand iron I
    use for all these tasks requiring lotsa' heat.  A 2 or 3-heat range
    gun is adequate for most other tasks.
    
    OK, ready to solder, right?  Wrong!  I apply solder paste to the
    intended joint at this time to further clean and prep the joint
    as well as to conduct the heat more efficiently.  NOW, we're to
    solder.  Make sure the soldering tip is clean and properly tinned;
    it should melt and hold solder readily and have a bright-shiney 
    appearance.  Touch the soldering tip to the intended joint, preferrably
    beneath the joint for max heat transfer. Touch the solder _to_the_
    joint_itself_, NOT TO THE SOLDERING IRON!  As soon as the joint
    is hot enough, the solder will melt and flow cleanly, thoroughly
    wetting the joint.  Remove the iron and DO NOT DISTURB THE JOINT
    'til it cools. Otherwise you'll wind up with a cold and/or inferior
    joint.  Once cool, the joint should look bright and shiney.  Excess
    flux can be easily cleaned with alcohol or [better] acetone.
    
    Now, stand back and admire a professional looking solder joint.
    
       

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

>    OK, ready to solder, right?  Wrong!  I apply solder paste to the
>    intended joint at this time to further clean and prep the joint
>    as well as to conduct the heat more efficiently.
    
    I assume you want to also avoid the use of acid based flux,
    and use only non corrosive products such as NO-Corode?
    
    Wayne
                                

    These are the 2 most important items that Al talks about.
    
    I have an el-cheapo propane torch that has been a huge time saver.
    With the torch, I am sure that the entire joint is heated enough.
    It only takes a few seconds in front of the flame.  No worry about
    the size of the saldering gun or anything.
    
    Since I started using flux, my solder joints have imporved 1000%.
    The solder now flows much better and adhears much better.
    
    cheers,
    jeff
    

Wayne,

>>    OK, ready to solder, right?  Wrong!  I apply solder paste to the
>>    intended joint at this time to further clean and prep the joint
>>    as well as to conduct the heat more efficiently.
    
>    I assume you want to also avoid the use of acid based flux,
>    and use only non corrosive products such as NO-Corode?
    
*  A B S O L U T E L Y !!  Acid core solders and/or solder pastes/fluxes con-
taining acid of any kind must be avoided like the plague!  I should also add 
that, when using the Sta-Brite variety of [so-called] silver-solders, the liquid
flux provided with the solder is used in place of a paste-type flux.

Bottom-line, if yer' seeing rust around solder joints, the chances are excellent
that your solder, paste/flux or both contain acid.  This corrosion/rust attrac-
tion property is progressive and will continue until somehow neutralized.  Plain
old, household variety white vinegar works well for this purpose and should be 
used to neutralize solder-joints if you're unsure of the presence (or lack of 
same) of acid in yer' solder and/or paste/flux....just wash/clean the joint 
thoroughly with the vinegar and this should do the trick.

IN NO CASE should acid-core solder or paste/flux be used for soldering electron-
ic components, battery-packs etc.

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

Well.....I do own a propane torch, I think I'll retire the soldering pencil 
I used and try the torch.  I have used it to do some amatuer plumbing.  
Hopefully it will solve my problem.  I've done a lot of electrical 
soldering also, but wasn't sure of the direction to take with these 
connections.

I plan on having the Strikemaster back in the air this weekend.  If not, 
at least I have the Kavalier and the Duraplane!

Anybody have any comments on the SIG Ryan STA (or was that STA Ryan...) yet?!?

Cheers
B-

    Brian,
    
    The propane torch wil work but is a bit of overkill in my opinion,
    especially if yer' not _real_ careful.  DO NOT OVERHEAT THE JOINT
    OR YOU'LL GET A POOR/DIRTY JOINT AND DE-TEMPER THE WIRE.
    
    The Ryan STA is a nice bird but has atrocious ground hndling owing
    to the narrow, still landing gear.    

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

    Do what I do, go to a car parts store and buy one of those little
    "Pocket" torches that use the CO2 cartridge sized propane
    cartridges.  They produce a real hot, small point flame and are
    VERY easy to control and direct.  The best part is that you don't
    have a 4 inch jet of flame to worry about using to mistakenly set
    your model, or your children, or your pets, or your home on fire. 

I found a miniature torch called the Pencil Torch.  It seems to work
quite well. You fill it with butane (the same stuff you refill butane 
lighters with) and one fill lasts about 8 minutes.  This thing was cheap 
too!!!

I'll let you know how well it works after I use it this weekend.  I was
messin' around with it last night and actually heated a penny till it 
glowed red!

Cheers
B-