Gettin me a boat fabricated and need to know a few specs on a trailer. I am gettin a 18x48 boat. I have ordered my axle and all the trailer hardware. I got a 3500# axle and 14" tires. I know it is a lil overkill but the price wasn't that much difference. I will probably built it out of 2x3 tubing. I build grills/smokers on trailers so I know how they go together and I know axle placement on a utility trailer. My question is do any of you guys have any specs on how long it needs to be and axle placement? If i had the boat here it would not be that big'a deal. Thanks

i just went outside and measured my dads 18.. its roughly 5 ft from the back of his boat / trailer to the center of the axle..

my 19 ft was right at 5.5 ft.




utility trailer is divide open floor by 1/2, then add an inch for every foot. that is where center of axle goes..

therefore a 18' trailer / half = 9 ft.. 18 ft = 18 inches.. so center would be 10.5 ft from front.

start your break/ wrap tongue at 3' from front.

i know u said u buidlin a boat trailer, but i would presume the breaking point for the wrap tongue would be the same. i want to say the formula for a boat trailer is 3/4 the length of the boat?

Take the length of the boat divided by 2 then subtract 2 ft . That will give you the measurement from the rear of the trailer for your axle placement. So a 18ft boat would approximately be 7ft form rear of trailer. Which gives you ample enough tongue weight ,but not too much that you can't pick it up..


Or you could weld the axle hangers to some angle iron that you would U-bolt to the trailer frame and it could be permanantly adjustable. Which is what we call a sliding axle. hope this helps.

Thanks guys. I have always did the inch per foot backspace on the utility trailers. I wasnt sure about the boat trailer. I just want to make sure that the boat is not hangin off the trailer a foot or two when I get it done. I also wasnt sure when to start the taper to the tongue up front. Jus10 is that the 3' you talkin about? Thanks

Tell me more about the vessel you are having constructed..

yep u got it. 3' behind the NOSE of the boat is where u start your bend at.

he must be talkin bout Brother Breaux



allow yourself roughly 4 ft of tongue in front of the nose of your boat. when u make the bend in your wrap, the channel should fall out roughly 18 inches behind the coupler. that is assuming your going with a 3" square tube center, 4" channel frame, and 2x3 cross braces.. reason i always used 4" frame tied into the 3" tubing is so it will overlap the tubing and have a more solid, factory looking weld.

Torsion axle!!!! Love em!

Will this pic help

Randy that your rig? Damn nice. U can put sum fish in there!!

I think you need to add another axle.....

lol those cats that run the locks down here shad dippin all got double and triple axle trailers. they put sum weight in them bitches...

Thanks, Jus10 I am thinking about building the complete trailer out of 2x3. Is that a bad idea?

Channel will not bow as bad as angle.. If ur gona custom build ur trailer,, dont try to cut corners do it rite the first time. May be a lil more money but its worth it in the end


Whos buildin ur boat? If its brother.. Get with him about helping u with a trailer. He also builds trailers..

I got 2x3 tube to build it out of, not angle. I forget the guys name who is gonna build it, I hear he is bipolar and I aint sure what he goes by.......today

what happened to 70/30 for single axle and setting the center of the tandems are the 70/30? Sounds like yall making it to complicated to divide by half, add 1" per foot, yadda yadda yadda.