[Richard Lee]

I am building a 1/5th scale Great Planes Cub that will see a lot of float flying. What long term damage can I expect after a number of flips in the water? I am covering with epoxy or polyurethane all surfaces I can get access to. I expect that after the plane sits nose down in water for maybe 10 minutes while awaiting rescue, water will seep into the leading edges of the wings and other areas. All the glues I have used are waterproof, by the way.

Does anyone have some experience of what long term damage I might expect? (My two existing float planes are foamies, so the occasional dunking is nothing more than a short term inconvenience.)

[Mark Winstanley]

Hi Richard; I think we met at an event last year didn't we?

Provided the plane doesn't get waterlogged (ie stays submerged for extended periods of time) the airframe should be fine. Most folks don't give this a second thought. The type of glue used should be a consideration but you seem to have taken that into account already. I would be more concerned about the engine as high wing planes, when flipped, will float with the nose fully submerged. You will have to try to get as much water out as possible before trying to start again. This shouldn't be a problem though. Also your radio gear will need to be dried out before flying again. I have dunked escs before one and they can be dried quite quickly. Test everything and range check before launching and most of all - have fun. Float flying is great fun - as is flying off snow.

Mark.

[Midair]

Hello Richard:

Like Mark wrote, Unless the fuse is submerged for an extended period of time, there should be no issues with water damage to the balsa, including warping. Most float planes that flip over in the water are retrieved within 10 mins - so no issues. Will your Cub be powered by a nitro engine or electric motor? Neither present a real problem, but I'll assume that you're running nitro and operating in fresh water.

For glow engines, once back on dry land, remove the fuel from the tank (unless you're absolutely sure that no water got in), disconnect the fuel supply lines (at the motor carb and muffler pressure nipple) make sure that there is no water in the lines. Refill the tank with fresh fuel, remove the glow plug and turn the engine over with an electric starter for five to ten seconds. Reconnect the fuel and pressure lines and again turn over the engine for five to ten seconds; the idea is to get fuel back into the engine. Once you see fuel spitting out from the top of the cylinder (glow plug hole), stop and reinstalled the glow plug. Attach a glow driver and start your engine. It should fire right away, no damage, no harm.

Almost all servos are water "resistant" so they should be fine, but if you're concerned, remove the case screws and case and check for water incursion. The receiver could get wet, but again if you open the case, you can dab away any water that got in, with a paper towel. In many cases you can still keep flying afterwards, but if the flip into the water ended your day, and you are concerned, you can use a hair dryer at home to slowly evaporate away any water that got into your electronic components.

We all know that water is a conductor of electricity, but it's a very, very poor conductor, especially at the low DC volts powering our R/C aircraft. Normally, fresh water shouldn't harm our electronic components. In my experience, I have never had an issue after dumping my floatplanes.

Peter

[machzx]

build her to fly not to swim

[Richard Lee]

Thanks everyone for the info. I feel much more comfortable that the occasional flip in water won't mess up the balsa too bad. I'll be flying a Saito 4 stroke nitro engine, so the drying out comments are very helpful. I will mount the receiver in a location where it will never get submerged in a flip, and I will wrap it in plastic as well. My float flying skills are improving, so I'm sure there will be less flips this coming summer. --- Richard

PS: Yes Mark, we have met at several Ottawa area events. Thanks for your comments.

[machzx]

I remember guys tying all components together incase of bad crash so you don't loose all yer bits

[ss40a]

If it flips do not set it upright until you have drained the water.

With glow I have just flipped by hand sloooooowly until the water is gone and then fire it up and run until quite warm and no water left. Then fly another day. Water should not get in the tank.

[Gizmoman]

Years ago I built several aircraft used exclusively for float flying.
Several things I did that worked well to keep water out:
Wing saddle area - widen the wing saddle at the fuselage sides and build a wing seat under the LE and TE areas. Make sure they match the wing curvature and use a quality foam tape such as the DUBRO stuff. Make sure the wing tightens snug to the saddle.
No pushrod holes - use only nyrod type such as the Sullivan Golden Rod. Modify the servo installs as needed to mount the servos inside the fuselage and wing. I used white lithium grease between the inner and outer nyrod as a water seal. All control rods were done this way.
Shrink plastic coverings do a great job at keeping water out if the edges are well sealed.
Put some loosely wadded paper towel inside the fuselage. It will absorb any water that might get in.
G

[stegl]

I would be more concerned with water in the electronics !

[oldtomcat]

Try this with electronics; spray all components with ACF 50 ( aircraft spruce).
Saw a display once at an aviation trade show: had a cell phone sprayed with ACF 50 in a glass of water. They called it and sure enough it answered by the ripples in the water. I was impressed!