This post is to educate and correct many incorrect assumptions made by individuals that don’t know about electricity as it relates to a drone making contact with water.
This information is provided by:
Drone-Retriever.com products which are designed for drone Rescue, NOT Recovery.
Rescue = save
Recovery = retrieval
Many people incorrectly assume that a drone that lands in water is destroyed due to the effects of electrical shorting. That is not the case and it will be explained below.
Additionally we will address what to do after a water event.
When a drone lands in salt water there are FIVE concerns a drone owner needs to be aware of:
DIRT and DEPTH, SALT WATER, TIME & CLEANING.
DIRT & DEPTH
Ocean water and lake/river water is not clean. There are many small particles of various organic and inorganic matter that will find its way into moving parts like motors, gimbals and fans. The biggest negative effect will occur if a drone sinks to the bottom where the point of impact will stir up everything at the bottom. Keeping a drone at the surface eliminates this issue.
As the drone sinks the water pressure will dramatically increase. This pressure will cause water and dirt to enter every microscopic opening as the air is forced out or compressed due to the increased water pressure.
Seals that are designed for normal operation will maintain their integrity when the drone is kept at the surface however this is not the case as depth increases. The greater the depth the greater the negative effects of pressure.
The pressure at the bottom combined with the stirred up dirt will facilitate the dirt being forced into smaller and smaller areas of the drone’s moving parts like motors, gimbals and cooling fans.
The effects of dirt is further addressed in the cleaning section below
SALT WATER:
Salt water IS NOT an ACID it is a MILD corrosive liquid.
Salt water or fresh water will not cause anything to electrically short out as the voltages within the drone electronics are too low to conduct through water.
Circuit Boards:
Most products like drones that are designed to operate outdoors have their electronic circuit boards protected with a thin blanket conformal coating on the entire circuit board and then an extra thicker coat on the soldered connections. This clear conformal coating protects the electrical circuits from high humidity and condensation. Additionally it protects the electrical system from salt water.
When flying near a coastline or over water the air is usually very moist and salty. Keep in mind that most high quality drones are designed to operate in moist environments without any issues.
Motors:
The motors that operate the props are made with anodized aluminum housings and copper wires along with bushings. The anodizing process creates a protective coating on the surface of the aluminum. The motor is made with a copper wire which is also coated with a protective coating primarily to keep it from shorting as it is wound very tight. Finally the motor is made with bushings at the top and bottom of the motor that allow it to spin freely. These parts are typically plastic and metal such that they do not need lubrication.
The motors are well protected such that when a drone lands in salt water that protective layer will protect the motors from short term corrosion. Keeping the motors at the surface will eliminate the issue of dirt and sand getting into the motors between the moving parts
Battery:
Most if not all drones operate with Lithium Polymer (LiPo) batteries. These batteries are constructed with multiple flat cells stacked on top of each other. Each cell is 3.7vDC. The battery cells are sealed in a plastic envelope. The only exposed metal parts from each cell are the leads. Most batteries consist of multiple cells connected in series and then sealed into an outer plastic envelop. This battery assembly is then installed into a hard plastic housing which makes up the battery pack. Water cannot get into the individual batteries but can get into the battery pack. Inside the battery pack is usually a circuit board that is used to control charging and monitor each cells voltage and temperature. Battery packs are usually sealed and may not fill with water if kept at the surface, but if allowed to sink to the bottom of the ocean then water impregnation into the battery pack circuitry will occur due to the higher external pressure.
Cameras:
The camera on a drone is a sealed unit which is required to keep it from experiencing condensation on the lens when moved from warm to cold environments or vice versa.
That seal is not designed to withstand the water pressure that would be found at the bottom of the ocean. However, if the drone is kept at the surface of the water the seals will be fine.
Gimbals:
Gimbals are made with elecro-magnetic motors. Like regular motors the components used are similar to those used for the propeller motors, keeping these at the surface and not exposed to the water pressure and dirt at the bottom of the ocean will help them survive a water event.
TIME & CLEANING
If a drone is recovered within hours not days and Cleaned according to this procedure everything should be fine. If it takes days or weeks to recover the drone then the corrosive effects from salt water will be evident.
If drone has been on the bottom even for a short time then cleaning the movable parts will be critical and may not be possible.
Immediately upon removal from the water:
Remove the Battery & SD card.
DO NOT spin the props or move the gimbals.
You must keep your unit wet with salt water until you can get to a bucket or plastic bag of fresh water.
Reason is that when salt water dries it will leave a residue that will not come off without scrubbing. That residue will be corrosive over time and it will have a negative effect on performance.
Put all parts into bucket of fresh water and aggressively shake the parts while they are under water. While shaking ensure that you rotate the drone under water so that every internal surface of the drone points upward while shaking. Then removed from water and allow the water to drain while rotating the drone. This will insure that fresh water gets into every open air pocket inside the drone. Additionally it is recommended to do this with at least 2 buckets of fresh water. Second washing is needed to insure that all salt water has been diluted and removed.
Fill a spray bottle that will shoot a stream of liquid with fresh water. Use this spray system to clean the motors by spraying between the stationary and moving parts of the motor. After spraying slowly turn the prop motor while spraying. Do this also for the gimbals. Also spray the USB port and any other electrical connector ports. Suggest using a vacuum cleaner to suck any water out of these ports.
Battery Cleaning: Submerge battery and look for a point where air bubbles rise from an edge. Mark that edge. Turn battery such that the edge with bubbles is pointing downward and look for bubbles on the now top edge. Mark that edge. Submerge the battery holding it so that either surface with bubbles is pointing up and hold in that position until no bubbles are seen (battery housing is full of water). Shake battery then drain from either edge that had bubbles coming from it. Repeat filling and draining procedure.
Using the spray bottle clean the battery contacts.
Drying.
Method #1: Heat your kitchen oven to 100°F (37.8°C) place drone in oven for 4-6 hours. Turn the drone so that all surfaces point upward. Battery will take much longer (days) to dry due to the relatively sealed nature of the battery housing. It is recommended to retire this battery for several months finding a place where the battery will be kept warm to facilitate thorough drying. You can discharge and recharge the battery which will assist in drying.
Method #2: Procure enough Isopropyl Alcohol 99.9% about 2 quarts and submerge the drone in the alcohol rotating the drone so that every internal surface becomes wet. Remove and let alcohol drain from the drone. The drone will quickly evaporate the alcohol if placed in a warm environment. As for the battery you will need to fill the battery with alcohol and then drain it. Heat an oven like Method #1 and place the battery in that oven with the fill edge pointing up. Allow it to heat for 2-4 hours to evaporate the alcohol.
Batteries from a water event should not be used until it can be determine that the battery charges and discharges safely.
This information is provided by:
Drone-Retriever.com products which are designed for drone Rescue, NOT Recovery.
Rescue = save
Recovery = retrieval
Many people incorrectly assume that a drone that lands in water is destroyed due to the effects of electrical shorting. That is not the case and it will be explained below.
Additionally we will address what to do after a water event.
When a drone lands in salt water there are FIVE concerns a drone owner needs to be aware of:
DIRT and DEPTH, SALT WATER, TIME & CLEANING.
DIRT & DEPTH
Ocean water and lake/river water is not clean. There are many small particles of various organic and inorganic matter that will find its way into moving parts like motors, gimbals and fans. The biggest negative effect will occur if a drone sinks to the bottom where the point of impact will stir up everything at the bottom. Keeping a drone at the surface eliminates this issue.
As the drone sinks the water pressure will dramatically increase. This pressure will cause water and dirt to enter every microscopic opening as the air is forced out or compressed due to the increased water pressure.
Seals that are designed for normal operation will maintain their integrity when the drone is kept at the surface however this is not the case as depth increases. The greater the depth the greater the negative effects of pressure.
The pressure at the bottom combined with the stirred up dirt will facilitate the dirt being forced into smaller and smaller areas of the drone’s moving parts like motors, gimbals and cooling fans.
The effects of dirt is further addressed in the cleaning section below
SALT WATER:
Salt water IS NOT an ACID it is a MILD corrosive liquid.
Salt water or fresh water will not cause anything to electrically short out as the voltages within the drone electronics are too low to conduct through water.
Circuit Boards:
Most products like drones that are designed to operate outdoors have their electronic circuit boards protected with a thin blanket conformal coating on the entire circuit board and then an extra thicker coat on the soldered connections. This clear conformal coating protects the electrical circuits from high humidity and condensation. Additionally it protects the electrical system from salt water.
When flying near a coastline or over water the air is usually very moist and salty. Keep in mind that most high quality drones are designed to operate in moist environments without any issues.
Motors:
The motors that operate the props are made with anodized aluminum housings and copper wires along with bushings. The anodizing process creates a protective coating on the surface of the aluminum. The motor is made with a copper wire which is also coated with a protective coating primarily to keep it from shorting as it is wound very tight. Finally the motor is made with bushings at the top and bottom of the motor that allow it to spin freely. These parts are typically plastic and metal such that they do not need lubrication.
The motors are well protected such that when a drone lands in salt water that protective layer will protect the motors from short term corrosion. Keeping the motors at the surface will eliminate the issue of dirt and sand getting into the motors between the moving parts
Battery:
Most if not all drones operate with Lithium Polymer (LiPo) batteries. These batteries are constructed with multiple flat cells stacked on top of each other. Each cell is 3.7vDC. The battery cells are sealed in a plastic envelope. The only exposed metal parts from each cell are the leads. Most batteries consist of multiple cells connected in series and then sealed into an outer plastic envelop. This battery assembly is then installed into a hard plastic housing which makes up the battery pack. Water cannot get into the individual batteries but can get into the battery pack. Inside the battery pack is usually a circuit board that is used to control charging and monitor each cells voltage and temperature. Battery packs are usually sealed and may not fill with water if kept at the surface, but if allowed to sink to the bottom of the ocean then water impregnation into the battery pack circuitry will occur due to the higher external pressure.
Cameras:
The camera on a drone is a sealed unit which is required to keep it from experiencing condensation on the lens when moved from warm to cold environments or vice versa.
That seal is not designed to withstand the water pressure that would be found at the bottom of the ocean. However, if the drone is kept at the surface of the water the seals will be fine.
Gimbals:
Gimbals are made with elecro-magnetic motors. Like regular motors the components used are similar to those used for the propeller motors, keeping these at the surface and not exposed to the water pressure and dirt at the bottom of the ocean will help them survive a water event.
TIME & CLEANING
If a drone is recovered within hours not days and Cleaned according to this procedure everything should be fine. If it takes days or weeks to recover the drone then the corrosive effects from salt water will be evident.
If drone has been on the bottom even for a short time then cleaning the movable parts will be critical and may not be possible.
Immediately upon removal from the water:
Remove the Battery & SD card.
DO NOT spin the props or move the gimbals.
You must keep your unit wet with salt water until you can get to a bucket or plastic bag of fresh water.
Reason is that when salt water dries it will leave a residue that will not come off without scrubbing. That residue will be corrosive over time and it will have a negative effect on performance.
Put all parts into bucket of fresh water and aggressively shake the parts while they are under water. While shaking ensure that you rotate the drone under water so that every internal surface of the drone points upward while shaking. Then removed from water and allow the water to drain while rotating the drone. This will insure that fresh water gets into every open air pocket inside the drone. Additionally it is recommended to do this with at least 2 buckets of fresh water. Second washing is needed to insure that all salt water has been diluted and removed.
Fill a spray bottle that will shoot a stream of liquid with fresh water. Use this spray system to clean the motors by spraying between the stationary and moving parts of the motor. After spraying slowly turn the prop motor while spraying. Do this also for the gimbals. Also spray the USB port and any other electrical connector ports. Suggest using a vacuum cleaner to suck any water out of these ports.
Battery Cleaning: Submerge battery and look for a point where air bubbles rise from an edge. Mark that edge. Turn battery such that the edge with bubbles is pointing downward and look for bubbles on the now top edge. Mark that edge. Submerge the battery holding it so that either surface with bubbles is pointing up and hold in that position until no bubbles are seen (battery housing is full of water). Shake battery then drain from either edge that had bubbles coming from it. Repeat filling and draining procedure.
Using the spray bottle clean the battery contacts.
Drying.
Method #1: Heat your kitchen oven to 100°F (37.8°C) place drone in oven for 4-6 hours. Turn the drone so that all surfaces point upward. Battery will take much longer (days) to dry due to the relatively sealed nature of the battery housing. It is recommended to retire this battery for several months finding a place where the battery will be kept warm to facilitate thorough drying. You can discharge and recharge the battery which will assist in drying.
Method #2: Procure enough Isopropyl Alcohol 99.9% about 2 quarts and submerge the drone in the alcohol rotating the drone so that every internal surface becomes wet. Remove and let alcohol drain from the drone. The drone will quickly evaporate the alcohol if placed in a warm environment. As for the battery you will need to fill the battery with alcohol and then drain it. Heat an oven like Method #1 and place the battery in that oven with the fill edge pointing up. Allow it to heat for 2-4 hours to evaporate the alcohol.
Batteries from a water event should not be used until it can be determine that the battery charges and discharges safely.
