Well, I actually don't own a Jon boat. I own a Pelican Predator 103. It's similar to a Jon boat http://www.pelicansport.com/en/products/fishing-bo...
Anyways, I needed a way to transport it to the water and back and boat trailers were way too expensive. I also can't find anything decent used for under 300$
I did find a cheap NEW trailer from harbor freight.
Being from Canada however, it posed a problem. Retail is 499$ USD + 89$ shipping to my US drop shipping center.. Then I'd have to drive down, pick it up, pay taxes, blah blah blah.. The Canadian dollar also is pretty bad right now, so it turns out to be over 800$ CAD when it's all said and done. The HF trailer does go on sale from time to time @ 349$ but then with shipping it still comes out over 600$.
So what I did was go on the classifieds and look for other trailers. I found this trailer for sale for 100$ CAD, but when I went to see him, I was able to get him down to 50$! Score! This will be the perfect base for my boat, but it will need some work.
Step 1: Remove the Old Tongue
The first order of business is extend the tongue. It's currently around 4ft 2inches long. It attaches to the front and middle cross member.
I'll be replacing it with an 11 ft 3x2" 3/16 wall steel tubing and attaching it to all 3 cross members front to back. In hindsight, 3/16th is a little overkill. If I was to do it again, I'd probably use 2x2 1/8 wall steel tube.
My boat is 10 ft long and I plan to have the boat hang off the back of the trailer 1 foot. So my 11 ft overall length trailer should be fine.
There were 4 bolts holding the old tongue onto the frame. I removed those pretty easily and mocked up the new tongue.
Step 2: Attaching the New Tongue
Next up is to center the new tongue on the frame, clamp it and drill the new holes.
Make sure you measure twice that it's centered and also check with a square that it's .. well square. you don't want it crooked or it will tow poorly.
Drill the holes and fasten them with bolts. I used grade 5 3/8 bolts with washers on both sides, a lock washer and loctite.
I was debating welding the trailer and I probably would have if I was building it from scratch, but there's nothing wrong with using bolts. Just make sure to loctite them or silicone the threads.
Because I used 3x2 square tubing I had to buy a new tongue. I was OK with this because the old tongue didn't have a through hole to put a retainer pin or a lock. When I was towing the trailer home, it actually opened and I almost lost the trailer. This won't happen with the new one!
As before, I drilled a 3/8 hole and I will use the same formula of grade 5 3/8 bolts, lock washer and loctite.
Step 3: A Little Paint
The trailer was a bit rusty. I sprayed it with some rust paint.
I painted the tongue with some bedliner spray paint.
Step 4: Bunks
So bunk brackets at the local store cost 19$ each. That's 80$ for 4!! Forget that.. I'll make some out of some scrap metal.
The above metal was taken from my office chair arms and some old shelve brackets.
The bonus with the store bought brackets are they are height adjustable, mine I'm making to be a static 6 inches.They will be able to pivot, but the height won't be adjustable.
The bunks themselves are made from 2 2x4x8's, pressure treated.
I wrapped them in outdoor carpet which was about 15$ (24 feet)
Step 5: Everything Else..
I attached the bunks, added some loops for holding down the boat.
The tongue coupler and safety chains were installed
and lastly the boat!