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turbine models are critical. Keep this in mind with everything you
do, every part you install...look at the work you just did, evaluate it
critically, and ask yourself "is this going to potentially crash my
airplane?" If there is any doubt about the work you have done, back
up, and re-do it properly.
Adhesives
The correct adhesive to use for all procedures is Loctite Hysol 9462.
This is a very strong white epoxy that is thixotropic. "Thixotropic"
means it does not run at all, but stays only where you put it. It is
infinitely superior to regular epoxy, even slow-setting epoxy, for our
purposes, because of this characteristic. Regular epoxy will run
downhill with gravity as it dries, taking it away from where it is
supposed to be. A good example is in the hinges...using regular
epoxy, a good portion of the glue will migrate down away from the
hinge into the inside of the wing as it dries, and you won't even
know it is happening. Hysol stays where you put it. The downside
of Hysol is it takes overnight to dry properly, but we have tried to
arrange things to keep you busy while waiting for glue to dry.
We also highly recommend that you only use a proper Hysol
dispensing gun, and only the long-type mixing nozzles.
The short nozzles do not mix this glue enough, and only a thin
nozzle and gun will let you fill the hinge and control horn holes
properly with glue, you can't do it mixing your Hysol on a flat surface
and trying to get the glue in the proper place by a brush or stick.
You can buy a complete Hysol setup with a gun, nozzles, and two
cartridges of glue from your dealer for approximately $60.
Consider it a great investment, the glue is the best you will use.
One cartridge is plenty to assemble your MB339.
Working with pneumatic systems
The MB339 uses pneumatic brakes and retracts. If you follow a few
tips, you should have very reliable, leak-free operation. Neatness
counts. All airlines should be secured to the airframe to keep them
from flopping around or getting kinked. Use tie wraps for this.
The other very important thing is to cut off the end of each airline
dead square before installing it on the nipple. This is VITAL. You
can either purchase a professional tubing cutter from your dealer
(they are approximately $10), or you can make up a little jig to hold
the airline and keep a sharp, new razor blade perfectly upright as
you cut. Either one works, just ensure that all ends of all airlines are
cut off dead square. Make sure all airlines are pushed ALL THE WAY
onto their nipples. They should not need to be secured otherwise,
but you can add fine wire safety wraps if you like. Make sure all left
and right matching airlines are the same length, particularly the
brake lines, or you will get uneven retraction or braking action.
It's worth taking the time to get everything pneumatic right the first
time, as having your landing gear fail to retract is not THAT bad, but
having it fail to deploy can really ruin you day and the paint on the
bottom of your model.