From Sam Speaks
A Micro Drop Glue Applicator for Indoor Models
by Roy Bourke-Markham Indoor Group
One of the secrets of building
light indoor models is to pay attention to the glue
joints. Excess glue is heavy, and does not
necessarily add strength to the joint. A good glue
applicator can go a long way to ensure the accurate
placement of just the right amount of glue to each
joint.
The accompanying sketch shows an excellent glue
bottle that can be used with acetone-thinned white
glue (Weldbond) or aliphatic (Titebond), as used on
indoor models. (Incidentally, I did not design this
glue bottle. It is available commercially for the
USA, but it is much cheaper to make one yourself.)
The best poly-bottle to use is a small food coloring
bottle (e.g. McCormack’s food coloring), but there
are several other poly-bottles that could be used
with minor modifications to the design. Begin by
bending a piece of 3/32-inch aluminum tubing to the
shape shown, and fit it to the plug that comes with
the poly-bottle that you are using. (Make sure you
make the lower bend such that you can still insert
the plug into the bottle without interference from
the tubing.)
Drill a small hole (.016) in the upper bend for the
wire tip cleaner, then cover the bend with a short
piece of silicone fuel line. Add a piece of
shrinkable tubing over the silicone tubing, shrink
in place, trim, then add the Pic Micro Dropper tip
to the end of the aluminum tubing. Make up the wire
tip cleaner, and insert it backwards through the
nozzle to pierce a hole in the silicone and
shrinkable tubings. Finally, reinsert the tip
cleaner from the back end of the nozzle, and the
glue bottle is complete.
To use the bottle, simply draw the wire tip cleaner
back only far enough to clear the narrow part of the
bore of the Pic nozzle, tip the bottle, and squeeze.
You will find you have excellent control of the
amount of glue that appears at the tip. During
storage, the tip cleaner is left fully inserted to
seal off the nozzle. Since polyethylene does allow
some evaporation of the acetone, you should check
the thickness of the glue periodically, and add
acetone as necessary.
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