.
Recommended Glues
There are so many different glues available today for model construction that it can be confusing to even the experienced
modeler. To simplify matters, most glues can be classified as one of four basic types:
1. Fast-drying cyanoacrylate adhesives ( abbreviated in these instructions as "CA") such as SIG CA, Hot Stuff, Jet, etc .....
2. Easy-to-use water-base wood glues such as SIG-BOND (yellow) and SIG SUPER-WELD (white).
3. Super strong two-part epoxy glues such as SIG KWIK-SET (5-minute cure) and SIG EPOXY (3-hour cure).
4. Traditional solvent-base model cements such as SIG-MENT.
Each of these types has different characteristics and advantages. Often times, the choice of which type to use is strictly a matter
of personal preference based on your prior experience with a previous model. However, because of the vast use of Lite-Ply and
hardwoods in the MID-STAR 40, we have found that the CA glues seem to work the best for general construction. In fact, the
construction sequence of the fuselage is designed with the use of CA glue in mind. Other glues could be used, but CA is
recommended as our first choice because of its ability to penetrate an already assembled joint. In other words, the fuse parts
can first be assembled dry (without glue), the alignment checked and adjusted, and then the glue can be applied to the joints.
You should also have on hand some epoxy (both 5-minute and slow dry) and Sig-Bond because these glues are called out in
several of the steps in this book.
Sig CA, like most brands of cyanoacrylates, comes in three viscosities - thin, medium and thick. An accelerator spray and
debonder are also available and are described below.
Sig CA Thin
- Watery in consistency, thin CA should only be used when the two parts to be joined are in perfect contact
with zero gap. Capiliary action pulls this glue deep into the wood resulting in a very strong bond and it dries in just a few
seconds. Thin CA can be used to tack assemblies together, but these joints should be glued again later with medium or
thick CA. Thin CA is also necessary for installing EASY HINGES.
Sig CA Medium
- Our medium thickness CA is excellent for almost any step during construction, and is particularly
recommended for gluing the plywood fuselage parts. The extra thickness allows the glue to fill small gaps, but it dries a
little slower than thin CA. If you want only one type of CA, use medium thickness.
Sig CA Slow
- This thickest formula is good for filing large gaps and building up strong fillets at joints requiring extra
strength. It also dries slow enough to allow you to apply it to one part and position it on another before it dries. (With thin
and medium CA's, the parts must be in contact and positioned correctly before glue application.) This feature is useful
when laminating large sheeted areas like a fuselage side and a fuselage doubler.
Sig Kwik-Shot Accellerator
- Spraying accellerator on CA (any thickness) will cure it almost instantly. Although CA is
fast, it's sometimes nice to speed it up even more.
Debonder
- This can be used to separate parts, but you'll probably use it for unsticking your fingers more than anything
else!
CAUTION
:
Some people have experienced allergic reactions when exposed to epoxy or cyanoacrylate glues. This is very rare.
However, it is always important that such glues, and also paints, thinners, and solvents, be used with adequate ventilation
to carry fumes away.
Engines, Propellers, And Mufflers
There is a tremendous variety of engines available in the size range
specified for the MID-STAR 40. Both 2-stroke and 4-stroke engines
work equally well in this model, so choose your favourite type,
keeping in mind the type or performance that you wish the model to
have.
Recommended Engine Range: .30 - .40 2-Stroke
.40 - .50 4-Stroke
If you want maximum aerobatic capability and vertical performance, use an engine towards the upper end of the recommended
size range. If the MID-STAR 40 is your first move up from a trainer, engine sizes from the bottom of the range may suit you
better. Engines at the bottom of the range will still put the MID-STAR 40 through most aerobatic maneuvers.
Use only propellers recommended in the instructions supplied with your engine. If you use a very high-power engine in your
model (such as a schneurle-ported 2-stroke .40), it's recommended that you opt for a propeller with a relatively large diameter
and low-pitch. This will give you loads of pulling power during maneuvers without a lot of excess speed. If you build the tricycle-
gear version and fly off grass, the prop diameter should be kept at 11" or less. If you fly off a hard-surface, you can use up to a
12" dia. prop.