Metal Prop Finishing Instructions
All Metal Props are shipped from the manufacturers to FunRCBoats in a "rough" cast condition. This means the prop must be hand finished before use. It is not difficult and our 9 step instruction will only take about 1 hour to properly sharpen, polish and balance your new metal prop. FunRCBoats also offers this service as a convenience to our customers who just want to “bolt on” their metal prop, at an additional charge.
Please use the following precautions when handling your boats Propeller:
Model boat propellers are VERY sharp and can cause serious injury or damage! Keep your boats propeller from coming in contact with ANYTHING on shore or in the water. Never run your boat near swimmers!
Before removing your prop: Be SURE the battery is UNPLUGGED & the boat is switched OFF before working on your boat.
If your prop is new, it will require some finishing work before use. Here is what we suggest:
1) This picture shows how to sharpen the edge of the prop with a 8" long fine, straight cut file at an angle to the edge of the prop. You ONLY do this on the "keyed side" (where drive dog locks in) of the prop. We also "roll" the file along the edge to create a radius between the sharpened edge and the surface. We use a piece of wood to make sure the "pushing side" of the prop does not get scratched or damaged.
2) The picture below shows the removal of the castings "flash" line on the prop's center hub. This is done carefully with the fine side teeth of a file. The center hub just needs to be smooth not necessarily polished.
3) Next make you sharpen both sides of the leading edges (sometimes referred to as the nose of the prop) to "cut" the water efficiently as the prop spins in the water. We do this with a small super fine file where we carefully sharpen the the front & back side of both leading edges of the prop to a sharp knife edge. This will be the only exception to polishing the one side we said to leave rough. The file marks must be polished smooth on each leading edge.
4) Square the trailing edge of the prop with your file. No polishing is necessary of this edge.
5) Balancing your prop for smooth vibration free operation and peak performance. This step is important for props 40mm and bigger.
6) Once the prop edges are sharpened and the prop is balanced, Polish the file marks out of the prop edges and surfaces with 2 steps of (400 & 600 grit) wet/dry sandpaper. Use a light coat of oil (motor oil works good) on the sandpaper. Remember to only FULLY polish the keyed side of the props blades. Again, we use a piece of wood to make sure the "pushing side" of the prop does not get scratched or damaged. Be careful handling the prop as it is sharp!
NOTE: Beryllium Copper dust is unhealthful to breathe or ingest. The manufacturer recommends that you do NOT use a buffing wheel, Dremel or other similar methods to polish or repair your prop as the particles will become airborne.
Therefore, we suggest working on your prop outdoors, over a disposable surface (like a paper towel) with a fine file and 600 grit sandpaper with light oil on it, to keep the dust particles from becoming airborne. All metal particles removed should be wiped off or up and discarded. Wash your hands thoroughly to remove any residue.
7) When installing the prop on your boat, be sure the prop is fully seated into the drive dog on the prop shaft. Sometimes it is necessary to file the slot or key "clean" for it to properly engage with the drive dog. We do this with a small file that is slightly smaller than the slot. Carefully file out the casting flash without widening the slot. Be sure to not overlook this area OR the prop will loosen up while you are running the boat and fall off in the water!
Then carefully tighten the prop nut while holding the blades (with your hand using a rag) Be sure not to deform the prop blades during tightening. We suggest using Blue loctite on the threads of all your set screws & nuts, especially the nut that holds on your prop on the drive shaft. Recheck your prop nut after every run.
9) Now you are ready to run your new metal prop! You will notice more consistent performance and better top speed (approx 3 to 5MPH).
If the prop should become damaged in any manner, the prop can be repaired by carefully reshaping the blade back to it’s original shape and repeating the steps above to sharpen, balance & polish it for use again. PLEASE use caution when handling and repairing your prop.