Prop tip damage.
Probably the most common prop damage This usually needs rebuilding and
shaping afterwards. If the material is soft and does not retain the
shape required, simply add a backing plate as described
with tape, and apply the repair material to the area using the tape
as a guide to work against. A number of applications may be required
with small air bubbles, indentations etc being refilled. As the material
dries it is further possible to sometimes mould it further into the
desired shape. Large chunks missing Hopefully at this stage of damage
the rest of your unit is still flyable (if not refer to Frame
repairs). Mostly this may be repaired using one or more of the
above methods, however sometimes wood must be added or spliced into
the existing prop. Afterwards grind down all excess material then use
sand paper proceeding to fine as a final finish.
Usually these are not repaired until the
blade is worn well away. It is howeveraesthetically pleasing to have
a good looking propeller that is in good condition.Sand blasting occurs
when warming up of the engine is undertaken on loose sand and gravel.
The sand is sucked through by the prop and simultaneously eats away
the prop on it`s way through . Repairs are undertaken by lightly sanding
the uneven areas, ending with around 210 grain. (IF USING WATER PAPER
LET THE WOOD DRY FIRST BEFORE PAINTING) . Painting may be undertaken
with either the aerosol type paintsor progressing up to 2k properties.
A primer may have to be used prior to painting.
Small Chips and Medium Holes.
Here two main options are available .
1. Laminating in another suitable piece
of wood. This is cut to fit the piece missing and glued in place with
a suitable wood glue or resin or epoxy. Heavy woods usually make re-balancing
difficult. The gaps are then filled as already described.
2. I usually place a backing tape around
the area that is missing. This is then filled with resin or epoxy or
similar material. The area once dry is sanded and refilled using one's
finger to force material into all the air bubbles and uneven areas.
Once again sand ending with fine grained paper. Trim the edges to the
same diameter as the opposite side. In order to attain the same dimensions
as the other side, place a piece of paper over the opposite edge and
draw a template and cut it out. Transport this to the mended side and
draw around the template. Sand the excess material away until the size
is exactly the same as the opposite.