Seaplane Float Sizing?

[Riley]

It wasn't 20 minutes after putting the 'floats for sale' ad in the classifieds that I rcvd a call asking "How much weight will they carry?" and my immediate response of 'duh" advertised my lack of product knowledge. I suppose a 'sink' test with sandbags would be proof of the pudding but it's a bit late for that. Can anyone advise if there is a simple formula (an oxymoron perhaps) to calculate the buoyancy value of a set of floats? Waiting with eager anticipation & much appreciation (but only if it's simple!)

 

Cheers Riley

 

 

[turboplanner]

This is really something for an aeronautical engineer, because length and placement come into the equation, perhaps ahead of the bouyancy/planing factors.

 

 

[Riley]

This is really something for an aeronautical engineer, because length and placement come into the equation, perhaps ahead of the bouyancy/planing factors.

Yeah Turbs, that's yet another area that would need specific study but fortunately there's a wealth of data & instructions available in layman's terms on the web addressing the correct mounting of floats to an airframe. As such, I wasn't anticipating any major hassles when I got to that stage (project now totally dead & buried) but the simple question of "how much airframe weight can the floats effectively and operationally sustain?" must have a reasonably-achievable answer so I'm hoping someone can beat some 'smarts' into me. cheers

 

 

[ahlocks]

Measure up the float dimensions and design draught and calculate that to a volume. Covert that displacement volume to the weight of water, fresh or add salt to taste, and that's the all up weight it will support at the nominated draught. It's rough as guts but good enough for gumint work...

 

Add on bit:

 

Doesn't allow for any structural limitations though

 

 

[Yenn]

If it is too difficult to calculate the flotation, just fill the floats to the flotation level and the weight of water used is the flotation ability within a whisker. That will not work if the floats have inbuilt foam or some other form of flotation.

 

 

[turboplanner]

We have some very lateral thinkers on this forum, a literal brains bank of problem solvers - great idea Yenn

 

 

[Riley]

Thinking about Ahlock's post over the weekend, I experienced an epiphany and came up with the very solution recommended by Yenn except that I was going to measure the volume of water needed to fill to the plimsoll line and convert that to a weight value. Fortunately there isn't any bouyancy medium in the chambers. Now.. how long will it take me to getting around to doing it? Thanks Ahlocks & Yenn and cheers to the rest of ya.