Constructing Floats
Constructing Floats By Ed Nogar and Woody Woods.
Please note that this handout was actually the instructions that came with their
manufactured floats which were sold under the name "Lakemaster Floats."
Therefore, when the text refers to "these floats" it is actually referring to
the Lakemaster Floats.
Finishing
The first step in finishing these floats by any of
the following methods is to sand the cores lightly and then vacuum them to
remove the sanding residue.
The most durable finish is obtained by first
covering the floats entirely with 1/16" sheet light-weight balsa, attached to
the foam with a foam-compatible contact cement. For additional strength, 1/64"
or 1/32" plywood may be substituted for the balsa on the bottom of the floats.
After sanding, cover the floats using ¾ ounce fiberglass cloth and epoxy resin.
The fiberglass cloth may be omitted, using only resin, with only a slight
reduction in strength. The floats can then be sanded, primed, and painted to
suit. This method of finishing results in a very attractive set of floats that
can be used form many seasons.
There are several other finishing methods that may
be used, but in each case the floats must first be reinforced since these
finishes do not provide any additional strength. We suggest epoxy-gluing a ¼" x
¾" spruce or plywood strip to the top of each float. This strip should run down
the center of the floats for their entire length. The floats can then be covered
with a low-temperature heat-shrink material such as Econocote, or with "duct"
tape, or plastic packaging tape. Another quick method is simply painting the
floats with a foam -compatible paint such as Formula U.
Mounting
In order to obtain optimum performance from your
floats there are several dimensions that should be adhered to when mounting them
to your aircraft. The floats should be mounted so that they are parallel to each
other with their step at the aircraft CG (center of gravity) as shown in the
drawings. The tops of the floats should be level when the plane is in its normal
flight attitude. There should be about two inches clearance between the bottom
of the prop arc and an imaginary line drawn between the tops of the floats. This
will keep the prop out of the water and spray. The distance between the
centerline of the floats should be about 25% of the aircraft wingspan. These
dimensions will often allow you to use existing main gear for one of the
attachments. In such cases you need only add the other support and you are ready
to go.
The drawings provided illustrate these points and
show how the floats are mounted to both conventional and tricycle gear aircraft.
Figure 1 shows how the gear is attached to the
floats. Note that the gear is attached to the reinforcing strip when one is
used. On balsa or plywood covered floats, a ¼" plywood plate, about 1" x 3" is
securely glued to the floats at each attachment point and the gear is attached
to them.
Figure 2 illustrates a method of constructing a
front mount for tricycle gear planes. Just replace the nose gear with this strut
and attach to the forward attachment points on the floats.
Figures 3 and 4 are side views depicting the
mounting dimensions already discussed and show a simple water rudder. A water
rudder, although not mandatory, is strongly recommended and is easily
constructed of 1/16" music wire and a piece of tin can or thin sheet brass. Two
or three square inches is adequate rudder area for these floats.
Figures 5 and 6 are front views of the front and
rear gear.
Click on the image below to enlarge.