Designing Purpose-Built Drones for Ardupilot Pixhawk 2.1

Testing for water-tightness

As we mentioned earlier, we are going to test for water-tightness at every stage of construction. This is just done by filling a sink with water, and putting the part of the model into the water until the water, is nearly at the lip, for a minute or two. We look carefully for any sign of water coming through the model. You can see this in the following image with the bottom-half of the duck before adding the ballast clay.

It's important to not only let the silicone sealant dry, but let it cure for at least 24 hours before doing this:

After the success of this test, we fill the ballast section with modeling clay, ...