I had a look through this forum and may have skipped over some of information I need. Firstly living in the UK I have had no luck in sourcing floats to suit a 84" piper cub I am building (powerplant is a 90 FS). The fuselage is around 49" so I think I need floats of around 36" in length.

I have been given a plan for 36" built up floats balsa covered and am prepared to go with this as a way forward. Comments ???

Question

I am trying to workout which is the best way to finish them. In my mind Im thinking glass cloth and paint but Im not too sure how much weight this might be. Solartex and paint is another which would be lighter. Any comments ????

In relation to weight what should the target weight be for 36" floats ??

Hi

I built some similar built up floats. They were quite tricky to build and even more difficult to seal, i ended up filling them with expanding foam, i glassed them but didn't bother painting them.

I never used them as a pair but both were used as a central float one on a fan dancer which i still have and 1 on a 80% solo which i sold.

Even with the expanding foam and glassed they are still quite light

I added the spray rails as depicted in the plan the floats worked very well on the water, are also far easier to repair than foam floats.

Simon

You can make your own floats. The Chuck Cunningham article that has been referenced here a jillion times, is the reference.

That article shows rectangular cross-section floats-I like to make them tetragonal or pentagonal-wider on the bottom, narrower on top. A 15-degree v-bottom is kinda neat.

I believe that article shows "2 inches" of float in front of the prop, but that ignores the size of the plane...My interpretation of that is: 20% of the prop diameter.

Don't worry about weight. You have plenty of wing area to support it, and lots of power on a cub of that size

Goldberg makes a float kit, as well as Arf's
Great Planes makes arf sport floats
Innumerable people manufacture foam floats in various states of finish. My favourite is Slocan Floats

As wayne22 said, don't worry about the weight, just mount up and go fly ! Chuck Cunningham's float parameters attached.

Thanks for time taken to post here a lot of my concerns have been put to rest. Thanks for help.

Now where that balsa knife .................

Can you get Great Planes stuff in the U.K? Their 40-size floats are perfect for a 1/5 scale Cub (if you meant 84 inch wingspan, then it's 1/5 scale). I have a set of these on a Hangar 9 80 inch Cub. I fiberglassed and painted mine, have been flying it for two seasons and have had no maintenance necessary yet.