New project - Third Log

[Triphammer]

So, I bought a 21" diameter 24 foot round log removed from a Grumman boat. This is to be the third toon on an 89 LOWE 20 ft. pontoon. with 19" wide 24 inch deep U tubes. First question. How long ( how far forward) should the middle tube be? Tritoons I've been seeing have all three matched up front. Some older boats have the center tubesticking out past the two outers. Aftermarket sellers list several shorter lengths as well as full length. Anyone got any thoughts?

 

[1960 Starflite]

Re: New project - Third Log

I'm surprised you haven't received professional feedback. I just hauled my center pontoon to the weld shop this morning. I shortened it 18" to match the outside pontoons. I was thinking about leaving it long, but boat just fits in boathouse as it is.

 

[Triphammer]

Re: New project - Third Log

Did your center extend beyond the outers in front?
How did it ride? Please comment back if anything changes.

Regardles of the loction of the front of the centertube, I plan on extending it back past the outers in the rear & either building a motor mount into the back of the log or setting my transom just behind it.This would be the easier of the two.

 

[1960 Starflite]

Re: New project - Third Log

My toon is an old 24 ft Harris FloteBoat with 19" toons. The donor boat had 23 ft toons. I positioned the rear of the center toon 2 ft in front of the engine, it happened to align with my 24 inch bolt centers. That made the front of the center toon stick 18 inches past the outside ones. As to the way it rides/handles, can't tell you yet.

Powered by 650 Merc, with me and my best buddy, Buford (dog) on board, smooth water, 13 x 13 prop, GPS at 18 MPH. I'm not looking for speed, just want it to sit a little higher in the water, Party times bring a load on board.

 

[crb478]

Re: New project - Third Log

I am doing this to my boat now, and I plan to make all three toons even in front as to where they hit the water. I have seen tritoons with the center tube forward, with it behind, and most with it even, The new boats that I am seeing are usually even in the front with the motor pod sitting back about 2 feet from the other toons. My boat will have a bigger center tube and will set back about 8 inches. Hopefully it will handle rough water better since this is what I am after.

 

[bav/270w]

Re: New project - Third Log

I did the same thing to my '89 lowe 20 footer. Except my log is 25"dia. and 24' long.
I first cut the log the same length as the other two and carefully removed the end cap to be reused. this will be hard to explain so bear with me. Your measurement may vary due to log dia. So measure and recheck and measure again.
App. 5 inches from top make 2 cut 16" lengthways on both sides on top and then cut over the top to where your first two cuts end and remove to section. this is the start for the new transom. Out of the 4' section I cut opp I cut a 30" piece and slit it along the seam so it would slide over the outside of the log. You will probably half to cut it to fit around the risers so it will slide on far enough to be even with end of log. Then cut to same shape as the end of log is. This will give you a double wall for added strength. Put end cap back into log for now to be welded later. I set mine in a couple of inches from where I cut out the top portion earlier. I reused the aluminum channel bracket that held the original wood transom and cut it to fit curvature of log and made a new wood transom. Find a good aluminum welder preferably a TIG welder. The Guy I had do mine did Okay but I have seen better. I did spread the area end of transom so it would fit the wood better. Due to the 25" dia I had some depth issues and trailor issues that I had to overcome but I don't think you should have any. If money is not an issue I would consider lift straits now while the tube is off. I'll post some pictures, hope it will help.

 

[bav/270w]

Re: New project - Third Log

Here are a couple of more pics that didn't go the first time. I know it looks crude. I had to make modifications along the way.
probably will make a few more changes still. As for as mounting The tube. I kept them all even in the front, mainly because of trailer. don't think you would gain any performance by extending center log forward. After all once underway the first 3-4 feet are out of the water. Unless you have a big load.

 

[dls322]

Re: New project - Third Log

That looks nice to me!

 

[Triphammer]

Re: New project - Third Log

It looks like you cut the back off the log & moved it forward & reworked the rear of the tube to be your transon. Yes?
Great idea! I'm looking at putting two 3x3 angle aluminumdown the center, about 16 inches apart & mounting the log between them. I'd extend the reat of the angles back far enought to locate my motor where I want it & hang the transom from the end of them.
What does your motor weigh? Mine is 300# & I'm not sure the thin walls of the log would support it. The top edges of my existing motor pod are some beefy extrusions (angles).

 

[bav/270w]

Re: New project - Third Log

Don't know exact weight of motor. It's a 93 115 evinrude. I'm sure it a good 300 lb plus. And yes the the rear of the tube is actually 3 ply thick. I put apiece of remaining cut pieces of the 4' section that was cut off the tube on the inside also. I also ran angle pieces at top and bottom of wood transom. The thickness of the sides is much thicker than the original transom. I'm very please with the added performance the center log gave me. I used 1" aluminum angles 3/4 the way up to bolt on the tube. Cannot see them in pictures because of the under sheeting. Which by the way I also recommend.

 

[BobGinCO]

Re: New project - Third Log

My third log is flush with the outer logs in the front, and ends about 2 feet short of the back - where the transom attaches to it. That transom piece looks like it's about 4 feet long, as the motor sits about 2 feet behind the end of the deck.