Float kits are rather expensive to install after the fact.  I have been told figures that a 172 will cost from $12,000 to $25,000cdn to install.  I depends on where it is done.  I would pick a shop that does a lot of them and they could be cheaper.  I talked to Baumann this summer and they do them and their quoted times seemed pretty good.

Most people say it is cheaper to buy a plane with it already installed.  Also the choice 172 has a O-360 in the nose.  You can never have enough horse power on the water.  Also a STOL kit is desirable.

A friend recently had one installed in a 180.  He was quoted about $40K by his regular AME.  Fortunately or unfortunately he had a nose over accident and had it installed as the plane was apart.  It still cost about $20K.

Ron

Price is just the parts and airframe work.  Then you have to buy floats and have things mounted specifically required by the floats you will use.  The parts and drawings are available from Cessna.  Used floats are about $20,000 and up.

Be careful on the size of the floats you use.  EDO 2000's are popular for 172's but these are too small for the plane.  It limits your gross weight to about 2100 lbs.  Going to a slightly larger float with an upgross on the airframe makes a big difference in what you can carry.

If you need the name of someone to talk that might have better information I could possibly get a name for you. 

Ron

Does anyone have any idea for instructions for installing floats on a C150 or C152

what is the stc number for floats on a 172

When you install a float kit on a Cessna 172 what do you do about corrosion protection. I have been told that the factory float planes from the Cessna factory are all zinc chromated inside and out before being riveted together. I have a 172 and have thought of doing the float kit, but I am concerned with corrosion. I would be operating the plane in a salt water envorment, if it was freash water then I wouldn't worry about it. If I alodine and zinc chromate the inside of the structure and skin then there is still a big chance that salt water can cause corrosion in the lap seams were there will be no zinc chromate.