Please note this thread has been inactive for 90 days. For the best results, please start a new thread.
Results 1 to 11 of 11
  1. #1
    Petty Officer 2nd Class
    Join Date
    Oct 2010
    Location
    on Guadalupe River
    Posts
    168

    Default Adding 3rd pontoon

    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.

  2. #2
    Supreme Mariner rickdb1boat's Avatar
    Join Date
    Jan 2002
    Location
    St. Louis, Mo
    Posts
    11,183

    Default Re: Adding 3rd pontoon

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

    "Boating is Life...All the rest is just Details"

    2007 Bentley 200 Cruise
    2007 Merc. 90 4 stroke

  3. #3
    Petty Officer 2nd Class
    Join Date
    Oct 2010
    Location
    on Guadalupe River
    Posts
    168

    Default Re: Adding 3rd pontoon

    Quote Originally Posted by rickdb1boat View Post
    Sounds good. Post some pics when you get it mounted and let us know how it went..
    My cross members are 2' on centers and the new Pontoon riser are spaced on 16" centers

  4. #4
    Vice Admiral 5150abf's Avatar
    Join Date
    Aug 2007
    Location
    Goshen Indiana
    Posts
    5,603

    Default 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.
    GO IRISH!!!!

  5. #5
    Petty Officer 2nd Class
    Join Date
    Oct 2010
    Location
    on Guadalupe River
    Posts
    168

    Default Re: Adding 3rd pontoon

    Quote Originally Posted by 5150abf View Post
    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 ,

  6. #6
    Lieutenant Commander
    Join Date
    May 2011
    Location
    NW Alabama Tennessee River
    Posts
    1,813

    Default 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.

  7. #7
    Petty Officer 2nd Class
    Join Date
    Oct 2010
    Location
    on Guadalupe River
    Posts
    168

    Default 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.

  8. #8
    Petty Officer 2nd Class
    Join Date
    Oct 2010
    Location
    on Guadalupe River
    Posts
    168

    Default Re: Adding 3rd pontoon

    Quote Originally Posted by Bamaman1 View Post
    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

  9. #9
    Petty Officer 2nd Class
    Join Date
    Oct 2010
    Location
    on Guadalupe River
    Posts
    168

    Default Re: Adding 3rd pontoon

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

  10. #10
    Petty Officer 2nd Class craigmack's Avatar
    Join Date
    Jul 2012
    Posts
    115

    Default 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.
    2012 Sylvan 8522 LZ LE Tri Toon w/ RPT tubes
    2012 Mercury 150 Fourstroke
    15"x15p Enertia SS (primary)
    15.25"x15p Black Max w/ extra cupping (spare)

  11. #11
    Petty Officer 2nd Class
    Join Date
    Oct 2010
    Location
    on Guadalupe River
    Posts
    168

    Default Re: Adding 3rd pontoon

    no problem with heat. not top heavy

Similar Threads

  1. Adding a swmming platfrom to a pontoon
    By Lovewell in forum Pontoons
    Replies: 0
    Last Post: March 4th, 2012, 09:26 AM
  2. Adding a 2nd Axle - 24ft Pontoon
    By samm835 in forum Trailers and Towing
    Replies: 4
    Last Post: June 17th, 2010, 01:18 PM
  3. Adding a toilet in a pontoon
    By JonathanEngr in forum Pontoons
    Replies: 8
    Last Post: July 14th, 2009, 11:06 PM
  4. adding a 3rd pontoon log to 2 log boat
    By djwalters in forum Boat Restoration, Building, and Hull Repair
    Replies: 12
    Last Post: November 20th, 2004, 10:28 AM
  5. Adding third pontoon setup question.
    By hollowoods in forum Non-Repair Outboard Discussions
    Replies: 3
    Last Post: November 8th, 2003, 04:33 PM
  1. iboats Forum Directory - Over 100,000 forum posts organized by topic