Decking a Pontoonboat

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cyberbadger
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Re: Decking a Pontoonboat

Post by cyberbadger » Tue Jun 28, 2016 4:42 am

Barts was right on the money. I couldn't read the original(Left in photo) without fifteen minutes of squinting. The boat was not only build in 1985 - It's capacity is 1985 lbs.
Replacement capacity plate I got - Ohio Watercraft Divison said it was fine to use a replacement capacity plate if it had the same numbers and info.

Image

In the Nyitra thread, a third 20ft 19inch diameter pontoon will be added from a loaner scrap vessel I got.

Code: Select all

pi=3.14159
r=19/2/12          - 19" dived by 2 for radius divided by 12 to get feet
r=.7916666666

h1=24                 - 24' pontoon
v1=pi*r*r*h         - Volume Calculation
v1=47.2547495736

v1*2                   - Times 2 for 2 24' pontoons
v1=94.5094991472

h2=20                 - Center 20' pontoon
v2=pi*r*r*h         - Volume Calculation
v2=39.3789579780

vall= v1 + v1 + v2 - Add Volumes
vall=47.2547495736 + 47.2547495736 + 39.3789579780 
vall=133.8884571252

buoyantweight = 133.8884571252* 62.4
buoyantweight = 8354.6397246124

bouyantweighthalffloating = 8354.6397246124/2 - Half Submerged, Divide by 2
bouyantweighthalffloating = 4177.319862306
I have to subtract hull weight - I can only guess 1000.

So now I have roughly 3000 lbs? Is this calculation correct?

---
Deck is 3/4" new Marine Plywood. A/B grade. I'm used Blue Water Alkyd Primer paint. And Blue Water Alkyd Royal Blue Paint.
I like how it says, "Not for sale or use by the General Public!"
Image

-CB
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cyberbadger
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Re: Decking a Pontoonboat

Post by cyberbadger » Mon Jul 11, 2016 2:15 am

Bump.

Can anybody check my calculations make sense?

Would appreciate it,
-CB
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barts
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Re: Decking a Pontoonboat

Post by barts » Mon Jul 11, 2016 3:30 am

I'd try to get a better idea of the weight of the boat as she sits at present, but your calcs make approximate sense.

Right now your boat can handle 2000 lbs w/ 2 24' pontoons. By adding another at 20', I'd think

2000 * (20 + 24 + 24)/(24 + 24) = 2833 lbs additional weight, assuming your additional
structure is proportional in weight.

- Bart
-------
Bart Smaalders http://smaalders.net/barts Lopez Island, WA
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cyberbadger
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Re: Decking a Pontoonboat

Post by cyberbadger » Mon Jul 18, 2016 12:48 am

The third pontoon has been mounted and bolted to the hull. The marine plywood has also been painted.

See my Nyitra thread for pictures:
http://www.thesteamboatingforum.net/for ... 005#p14005

-CB
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cyberbadger
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Re: Decking a Pontoonboat

Post by cyberbadger » Wed Oct 19, 2016 9:07 am

fredrosse wrote:You can use 3/4 fir exterior plywood, exterior rated. But it will check with just paint. .
Listen to Fred CB! :cry:

I am currently not happy with my Deck paint situation that I used as described earlier in this thread.

Some of the sheets on Nyitra are ok. However, some of them checked as Fred said within a month!

Some steamboating stuff you have to learn for yourself the hard way.....

-CB
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barts
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Re: Decking a Pontoonboat

Post by barts » Wed Oct 19, 2016 4:54 pm

Fir plywood w/o glass will always check given time, even if you coat it w/ epoxy before painting.

- Bart
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Bart Smaalders http://smaalders.net/barts Lopez Island, WA
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