I'm interested in building an electric powered sea plane or float plane. I think something glow-40 sized should provide minimum building effort, yet acceptable flyability. I have the RCM plans for their Aquastar, but am concerned with the additional weight of electric... it may not perform well.

Any comments/suggestions?

40 sized is a little on the large side for an electric. The motors and batteries may be expensive.

Usually when a glow plane is converted to electric the additional weight of the batteries is compensated for by lightening the structure. Electric motors produce almost no vibration; glow engines constantly try to shake the plane to pieces.

I think www.hobby-lobby.com has some electric seaplanes, you could check there. Also you could just put floats on a regular plane. Cubs look pretty neat on floats.

It it was my choice for an electric floatie, I think I would be looking at the Sig Rascal, Thunder Tiger Sparky or SR Cutie on a nice light set of foam floats. These are all smaller than .40 -size airplanes, but they fly well and would tolerate the floats. Hobby Lobby Donald has been around a while, if you want an ARF Flying boat.]

If you want to convert a .40 size plane to floats, think about a sig Kadet Senior or a Telemaster .40. With a geared Astro .40 cobalt, these should fly fine. Note: A geared prop is larger diameter. You may need to make it sit pretty high on the floats for the prop to clear the water.