Miller Electric

Welding Discussion Forums

Home » Resources » Communities » Welding Discussion Forums

  • If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.


Announcement Module
No announcement yet.

The Pontoon Pirate sails again.....

Page Title Module
Move Remove Collapse
Conversation Detail Module
  • Filter
  • Time
  • Show
Clear All
new posts

  • The Pontoon Pirate sails again.....

    I actually finished this project in June, but haven't had time to post it here. This will be in multiple posts, because this forum only allows 4 images per post/

    First some background. I've been welding for about 35 years since I learned to stick and OA weld on the farm as a teenager, but I would consider myself a hobbyist welder since I was never paid as a "weldor". (I did work as a heavy equipment mechanic many years ago that involved welding as part of repair duties, but not that often.....)

    About 10 years ago I started getting into restoring old cars and doing large art projects, and bought a Miller 180SD Syncrowave. At the time, I really wanted a 250 Syncro, but couldn't afford it. About a year ago, I came across a nice 350 Syncro with a blown main board on the cheap and bought it. It only took a couple of hours to troubleshoot the problem and fix it, so now I had a nice 350, much bigger than I wanted, but I have the space (and power) to feed it. I sold the 180SD.

    We have a small house on a lake, so we have a bunch of water toys, ski boat, jet skis, etc. For the last couple years, I thought it would be nice to have an old beater pontoon boat, and had this wild hair idea to get an old pontoon, put an upper deck on it, and put a slide on the upper deck for the kids. In January, I was browsing Craigslist, and saw a pontoon for sale locally really cheap, with motor and trailer. Showed the picture to the wife, and she said "go for it". A few hours later, I was towing home the pontoon, no clue if the motor was any good (it was like zero degrees out! Fortunately, the engine was in good shape, I later discovered).

    Here's a photo of the pontoon as I bought it, before work was started.

    Designing the upper deck and slide took a long time. I looked at a bunch of doubledecker pontoons on the web, and didn't really like how any of them were built. Most of them had a multiple gusset type of construction. I wanted to keep it super simple and robust. I opted to build a deck 76" wide (to have the uprights centered on the centerline of the pontoons) and 96" long. Once I had it all designed, I pondered how to attach it all to the pontoon.

    The deck of the pontoon was generally in OK shape, just one soft spot, but since I had to strip off all the furniture and parts of the deck to weld the attachment points onto the pontoon, I decided to put a new deck and carpet on it. So the next stage was to strip it all down to bare deck.

    Now came the fun part; welding up the upper deck assembly and mounts. I opted for 4"X4" 3/8" thick T6061-6 angle for the uprights, 3" T6061-6 channel for the upper deck floor joists and side rails, 2"X1/4" thick T6061 bar for angle bracing. I fashioned a jig of 2 X4's to hold the heavy aluminum channel uprights in position, and welded the whole thing in my garage.

    While I have welded a lot of aluminum before, I admit that virtually all of my aluminum welding experience was with material in the 1/16" to 3/16" range. Welding the 3/8" thick stuff was a whole new experience! When I bought my 350 Syncro, I never envisioned using anywhere near the max output. But here I was, welding the 3/8" thick angle on this project with the controller maxed out. The 1/8" 2% Lanthanated tungstens were not quite up to the task; I should have had 5/32" or larger, but didn't have time to wait to buy them online. I also had to switch out my lightweight TIG safety gear to high amp stick gear; darker lenses, thick gloves, sleeves... (I sunburned my bare arms badly on the first day....)

    The other challenge was weld positioning. Usually when I TIG weld something, I have it nicely fixtured on a table, with horizontal welds. This project required lots of time up on a 8 foot step ladder, reaching out, overhead, etc. Fortunately, I have a nice slider hand controller that I learned years ago to use while Tigging out of position under cars, so I didn't have the learning curve of switching from pedal to hand control. (Also, I found that with the 1/4" and thicker aluminum, I could just basically turn it on to a set point and alter speed to control heat, just like O/A welding...)

    With all of the out of position stuff, the welds were not as pretty as I would like, but hey, they are functional.

    Once I built up the upper deck, I then built the mounts to the pontoons. I built them out of pieces of material I used for the upper deck and uprights. The rear mounts were easy as there was already a riser in place to simply weld a reinforced plate to the risers. The front mounts were fashioned out of the 4" angle butt welded with a 3" spacer to form a heavy channel. I welded a 12" long piece of the 4" angle to the top of the channel to form upright stubs that I would bolt the deck uprights to. This channel was then welded to the pontoons.

    Here's a photo showing how the front mount is welded to the pontoon.

    And here is a photo of the stripped deck, with the mounts positioned in place for welding.

    Another photo of the front deck mount, shown between the two existing deck mounts on the pontoons. (I don't know what they used to weld the existing deck mounts; they look pretty rough...)

  • #2
    The Pontoon Pirate sails again.....

    After I installed the deck mounts, I re-decked the pontoon using 3/4" marine plywood and nice carpeting, cutting slots in the plywood to fit over the 4" angle stubs protruding from the deck.

    Now came the fun part of attaching the upper deck assembly to the pontoon. I didn't have anything to lift the upper deck assembly that could reach over 14 foot tall to place it in upright, so I had to improvise. I first used my JD loader to lift it horizontally against the stub mounts on the one side. (with blocks under the trailer to tip the pontoon deck towards the tractor)

    Then I got underneath it and tipped it up the rest of the way:

    Once I got it in place, I clamped the uprights into place on the mount stubs, and drilled four 1/2" holes to bolt the uprights securely to the stub mounts:

    Then came the slide assembly. I found an old pool slide on Craigslist, sanded it and repainted it, then fabricated mounts, using the old round aluminum mounts welded via pads to angle aluminum. This was actually more challenging than it sounds, since the angles to cut were compound, and I had to weld it in place outside, on a windy day. Even though I put up a tarp around me, the shielding gas kept blowing around, even with gas lenses.

    This picture is not the best, but it shows the backside of the slide and mounts:


    • #3
      For the ladder to get to the upper deck, I simply went to Home Despot and bought an aluminum extension ladder, cut it to size, and welded plates on top and bottom to fasten it into place.

      I wanted to have a 24" high safety rail around the upper deck. I struggled with how I was going to build it, when an idea struck me. This pontoon came with a canvas top with an aluminum frame. The frame was made of 1" square tubing, with nice 90 degree curved bends. The radius of these bends matched the radius of the bends on the safety rails of the lower deck. I simply chopped up the old canvas top frame, added some straight sections and welded it together. It looks a bit "frankenwelded" or cobbled together, but it is strong and doesn't look bad from a distance.

      Here's a photo showing both the upper ladder mount and the upper deck safety rail mounts:

      And here is a photo of the completed upper deck:

      Here's a closeup of the outside corner detail, where the 3/8" thick angle uprights, the 3" channel, and web bracing come together:

      For a party boat like this, we needed to have a sound system. I had an extra set of waketower speakers (they were no good for a waketower, but fine for this application) and mounted them underneath the deck. They are powered with an extra 500 watt amp I had, and fed with an Ipod compatible Sony stereo system:


      • #4
        I painted over the original color scheme with a gloss black urethane, and my wife ordered some neat decals for the doors:

        And here is a photo of the completed project, resting at the lake:

        I also added a small water pump to trickle water down the slide. One final cool addition; a 13 watt solar panel to keep the battery charged up (the tiny alternator on the outboard wouldn't be enough to keep the battery up to snuff.) It kept the battery always up at full charge.

        Finally, here's a photo of the slide in action. We've had a great deal of fun all summer on this boat, and plenty of positive comments. I'm already thinking about new mods for this boat for next summer.


        • #5
          Looks Good

          And it looks like a lot of fun,One question what bender did you use for the upper rails around the slide?.Thanks Mike


          • #6
            The bent pieces on the upper deck railing were part of the original canvas top that came with the boat. I simply cut up the old frame and cobbled it together with extra 1" tubing I bought. I had no way of cleanly bending the square tubing like that, so I am glad I had the old frame that had these bent pieces already. Go Recycling!!


            • #7
              One point I forgot to add. My oldest had a bunch of friends over, and before I knew it, there were 10 people on the top deck! I purposely overdesigned the upper deck, so it handled it fine, but the rear of the pontoon was almost completely submerged in water! Probably would tip over before you put enough weight to damage the upper deck assembly.

              The family rule is now a max of 3 adults on top.......


              • #8
                You could probably add some additional flotation to the rear.Mike


                • #9
                  Maybe some overload pontoons under the main deck?

                  Looks like a lot of fun!


                  • #10
                    Very nice project Jeff

                    Another half pontoon located near the stern is probably the most logical. Have you given any thought to float bags?

                    Might just be too many years of building handrails for commercial applications, but 24 inch tall handrails raises the small hairs on the back of my neck!


                    • #11
                      Originally posted by Sonora Iron View Post

                      Might just be too many years of building handrails for commercial applications, but 24 inch tall handrails raises the small hairs on the back of my neck!
                      If you look at the final photo, you will see that the upper rails match the height and style of the railing on the lower deck. 24" is somewhat a standard height for pontoon side rails. I've never seen or heard of anyone falling over the side rails on a pontoon boat, so I figured that the same for the upper is OK. Most of the users of the upper deck are kids, and the 24" height is fine for them anyway....

                      Also, I've seen a number of double decker pontoons, and a lot of them have only 12" side rails!

                      Another point of consideration is the total overall height. When I have this mounted on the trailer, the height of the slide, which is a little above the handrails, is 13 foot even. 13' 6" is the standard legal height. I couldn't have railing much taller and still be legal on the road....


                      • #12
                        Dont take me wrong here Jeff; youve done a fantastic job! I dont know anything about boat building. Just seems as that handrail is more of a tripping hazard than fall prevention. In a commercial application 42 for platform handrail and 37 for stairways.


                        As long as your insurance agent is happy Im


                        • #13
                          I noticed that the Miller ads were obscuring the first post, so I resized the photos to make it more readable.....


                          Special Offers: See the latest Miller deals and promotions.