Adding 3rd pontoon

luckyjr

Petty Officer 2nd Class
Joined
Oct 2, 2010
Messages
169
bottom.jpg33boat.jpg

Bought a new 25' x 25" with strakes for a good deal and ready to install. I am bolting a 2 x 2 x 1/8 sq tube across the existing riser. They will be 36" long for easy access for bolting to the cross member. Think I will use a U bolt type. My floor allows me space above the crossmember to do so. This allow for the 3rd to be 3" lower in the water than the outside toons.
 

rickdb1boat

Supreme Mariner
Joined
Jan 23, 2002
Messages
11,195
Re: Adding 3rd pontoon

Sounds good. Post some pics when you get it mounted and let us know how it went..
 

5150abf

Vice Admiral
Joined
Aug 12, 2007
Messages
5,808
Re: Adding 3rd pontoon

Every 3rd one will hit a crossmember, carefully cut off the ones that don't hit off and have them welded back on where you need them to sit, should work out fine.

If you use you same welder just don't let him pressure test it.
 

luckyjr

Petty Officer 2nd Class
Joined
Oct 2, 2010
Messages
169
Re: Adding 3rd pontoon

Every 3rd one will hit a crossmember, carefully cut off the ones that don't hit off and have them welded back on where you need them to sit, should work out fine.

If you use you same welder just don't let him pressure test it.

Appreciate the opition. What about this? Buy 2pc 25' long 2x2x1/4" and bolt them to the exisisting 3rds risers. Use a template to drill out the cross members on the boat spacing 2' cc. Place that template on the 3rd and pre drill the connection holes in the 3rd making sure none of the 3rd riser foul with cross members on the boat ,
 

Bamaman1

Lieutenant Commander
Joined
May 15, 2011
Messages
1,895
Re: Adding 3rd pontoon

Straight talk:

Your third toon with strakes may be a little overkill. The purpose of the strakes is to get the boat's nosecones out of the water where the boat can run quickly and efficiently. They're also good for carrying large crowds or heavy weights (without strakes.)

But we seldom see a boat with a cabin that has the horsepower to plane off and use the strakes. If you're running 150 horsepower, you should be very careful, as your boat may not be as seaworthy as you'd like it to be. I hope I'm wrong.

And, you'll need to go to a different kind of trailer with the third toon--and have the outside bunks raised high enough for the larger toon to clear the boat frame. The middle toon also needs to be supported.

Good luck on you project.
 

luckyjr

Petty Officer 2nd Class
Joined
Oct 2, 2010
Messages
169
Re: Adding 3rd pontoon

PONTOON 3RD SMALLER.jpgBama, thanks for your comments. I am carring my kids and grand kids on this boat and safety has been my main concern. Most all the weight of this boat is no higher than 3' from the deck. The roof supports weigh 160lbs spread over 19lf. The roof decking weighs the same. The rubber roof weighs 48lbs plus 90lbs for the AC. 24lbs per lf spread down the 19lf. The design / \ to center the top weight inside the pontoons and help with side winds. The pontoons will support 9000lbs at 50% submerged. I have two pontoon out riggers that extend to 14' wide in case of rough water. Lastly I pull a 14' fishing boat and Kayat on top of cabin. The strakes came with the pontoon and the boat is for cruising and staying in the slip.
 

luckyjr

Petty Officer 2nd Class
Joined
Oct 2, 2010
Messages
169
Re: Adding 3rd pontoon

Straight talk:

And, you'll need to go to a different kind of trailer with the third toon--and have the outside bunks raised high enough for the larger toon to clear the boat frame. The middle toon also needs to be supported.

Your right
Here's an idea I'm thinking about. Modifying this trailer by turning it upside down and extending the present boat supports to fit the 3rd. Cutting the present axel assembly down and position it in a fixed spot inside like it is now. Then, adding a third low profile axel to 8'6", I heard that I could get 1000 to 1500 for my 29' carriage trailer. It's in good shape with good tires. If that is true I would probably sell and get one to fit.
ATRAILERta700.jpg
 

luckyjr

Petty Officer 2nd Class
Joined
Oct 2, 2010
Messages
169
Re: Adding 3rd pontoon

Mrs.jpg
The Mrs helps getting in those very tight places to make the connections.
 

craigmack

Petty Officer 2nd Class
Joined
Jul 16, 2012
Messages
137
Re: Adding 3rd pontoon

With all that weight that high up I would think it'll sway quite a bit. AC? Are you running this off a genset or a large inverter? If heat is an issue I would have painted it white and not black.
 

luckyjr

Petty Officer 2nd Class
Joined
Oct 2, 2010
Messages
169
Re: Adding 3rd pontoon

no problem with heat. not top heavy
 
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