Bunk boards

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Douglasdzaster
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Bunk boards

Post by Douglasdzaster »

Hello everyone,
I have a 1983 , 16/52 Monark jon boat. It’s time for new bunks and I’d like to change. I’ve been messing with it since I got it a year ago to load and unload easier. It’s currently sitting on 4 , 2x6 board’s with carpet and slick strips. The boards are edge ways and even with the boards all the way down the boat never touches the big rollers in the middle. I’ve looked at laying the boards flat but they won’t fit between the chines. I’m wanting to replace with 2x4 boards. They will fit the brackets. And should have it sitting just about right on the trailer. I just don’t know if they’ll hold up. The boat with motor and all the gear is a little over 700 lbs.
Does anyone else have a boat close to mine sitting on 2x4s?
I’m also putting a cross bunk under the bow for support.
1983 Monark 1652 / 1992. 3 cylinder 40 hp. Yamaha

Douglasdzaster
Posts: 115
Joined: 19 Sep 2020, 09:15
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Location: Smithville,Texas

Bunk boards

Post by Douglasdzaster »

UPDATE: I found another thread on here and it happened to have a gentleman on it that has a 16/52 . He removed the rollers and it’s now on a couple of flat 2x4s. I’m going to use 4 so I should be good. This is really going to help me off the trailer.
1983 Monark 1652 / 1992. 3 cylinder 40 hp. Yamaha

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JL8Jeff
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Bunk boards

Post by JL8Jeff »

I'm not sure you need 4 bunks, I have 2 bunks that are 8' long and I thought it wasn't enough but most of the weight is at the back where the motor/gas/battery is. The pvc downspouts cut in half work great for helping it slide on/off and they are thicker/sturdier than the wrap around bunk slides you can buy (I tried them on my other boat and they worked well, but they are thinner material). Just make sure you get the bunks lined up between the chines and it pretty much becomes self centering when you load it. The center roller doesn't really take any weight, it's just to protect the boat from hitting the trailer itself. The front bow stop will help take the weight up front.
2001 Lowe Roughneck 1652 VT with Merc 60/45 jet 2 stroke

Douglasdzaster
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Bunk boards

Post by Douglasdzaster »

Thanks for the reply I appreciate it.
I was thinking 4 because that’s what is on it now. 2x6s on their edge (way overkill).I’ve been wondering if 2 would work since I saw your trailer in the other thread. I’ve been working on this project for a year. As soon as I got it running I’ve been using it quite a bit between these other repairs and I get wet because every time I have to shove it off the trailer. I’ve figured out the trailer is a little small for the boat also. I had to move the winch up towards the hitch and raise it to get this far.(the boat was hanging of the end a little)There’s a 5” roller mounted on the trailer just before the keel area which the boat rest on with to much weight on it.( was doing that before I moved it) I have a front support cross bunk coming to replace that.
I wonder how far past the mounting bracket I can safely make the new bunk boards? I’d like to move the boat back and have more tongue length on the trailer.The only weight I have in the stern is the outboard (152 lbs.) it’s a pull start so my trolling battery is on the front. Fuel tank is in front of the back seats because it doesn’t fit behind the seat.
1983 Monark 1652 / 1992. 3 cylinder 40 hp. Yamaha

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JL8Jeff
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Bunk boards

Post by JL8Jeff »

I'm not sure how far back is the limit for the bunks and the rear crossmember where the bracket will mount. My rear crossmember is still in the spot where the factory mounted it and my bunks extend about 12-14" past the crossmember. I don't think you want to go too far back, especially if your trailer is already undersized. You might be able to find a longer tongue searching around Craigslist or FB Marketplace or if you have a marine place nearby they might be able to order one vs paying shipping from somewhere online. I actually cut my tongue shorter so I could fit the boat/trailer in the garage for the winter.
2001 Lowe Roughneck 1652 VT with Merc 60/45 jet 2 stroke

Douglasdzaster
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Location: Smithville,Texas

Bunk boards

Post by Douglasdzaster »

Here’s a couple of pictures.
The 5” roller is farther back than I said and you can see wear it’s scared the boat. I don’t know what kind of coating that is either so I’m not sure how to cover the bare aluminum up once I fix that problem. The other picture shows I now no why the boat is up so high and I can’t believe I hadn’t seen it before. The boat won’t fit between the fenders. I’m going to try and do some modifications to the fenders so I can still use 2x4s. I just won’t be able to lower it as much as I wanted but even 2” would help.
752339E3-733B-428F-8E7E-DE19BABFF648.jpeg
CD64B023-DA47-46D3-9653-98A6FF896023.jpeg
I was at my son’s house yesterday and got with him about bringing his welder over one weekend and I’ll have the stuff to do it with hear. He’s already building me a BBQ pit here anyway. Lol
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1983 Monark 1652 / 1992. 3 cylinder 40 hp. Yamaha

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JL8Jeff
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Bunk boards

Post by JL8Jeff »

Those bunks look pretty short and the axle does look narrow which limits how much you can lower it. I would take the time to look around for another trailer before spending too much time, money and effort on it. It looks like a tilt trailer so you might be able to get some ok money for it unless you really need the tilt option. I've never had a tilt trailer so I can't say if it adds value. You might be able to swap out the square fenders for rounded off ones which will allow you to lower the boat, but when you add up all the little stuff you want to do, it's probably cheaper to look for a different trailer and sell this one to offset the cost.
2001 Lowe Roughneck 1652 VT with Merc 60/45 jet 2 stroke

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LDUBS
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Bunk boards

Post by LDUBS »

I cannot imagine an issue with swapping out the on-edge 2x6's for flat 2x4's. You would have to raise your bunk brackets. The existing rear brackets look long enough to do that. I'm not sure about the front ones -- they might have to be replaced. A swivel type piece of hardware, like shown in the pic below, is typical for connecting the flat bunk board to the bracket.

I tend to agree with JL8Jeff about the bunks looking short for your boat. I don't have a remedy to suggest.

I have this thing about a boat's keel/center fluke (whatever it is called) sitting with weight on multiple center rollers. To me they are contact points that will create dents as the boat/trailer bounces along the road. But, I've never had a Jon boat. Maybe they are different, IDK.

Screen Shot 2021-12-28 at 9.51.06 AM.png
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Have Rod - Will Fish

Douglasdzaster
Posts: 115
Joined: 19 Sep 2020, 09:15
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Location: Smithville,Texas

Bunk boards

Post by Douglasdzaster »

LDUBS wrote: 28 Dec 2021, 14:14 I cannot imagine an issue with swapping out the on-edge 2x6's for flat 2x4's. You would have to raise your bunk brackets. The existing rear brackets look long enough to do that. I'm not sure about the front ones -- they might have to be replaced. A swivel type piece of hardware, like shown in the pic below, is typical for connecting the flat bunk board to the bracket.

I tend to agree with JL8Jeff about the bunks looking short for your boat. I don't have a remedy to suggest.

I have this thing about a boat's keel/center fluke (whatever it is called) sitting with weight on multiple center rollers. To me they are contact points that will create dents as the boat/trailer bounces along the road. But, I've never had a Jon boat. Maybe they are different, IDK.
As of now I’m still planning to change to flat 2x4s and adjust the brackets like you said. I was just hoping to go lower that 2”. I have some room between the fenders and tires that will let me move each one out a little wider and maybe then I can drop it lower. You’re correct about the front. That’s the second roller I’ve put on in a year. The boat must be pretty tough not to have dented. Took off some of the bottom coating though and scratched it good unloading.Tomorrow I’m getting a bracket that goes on the tongue and has a 2 foot 2x4 going cross ways. Then I can throw that roller in the trash. The boat doesn’t rest on the roller in the front. It helps load and unload.
I’m going to have to put off the bunks for a short time. Turns out I need a new floor I’m currently working on. I discovered the previous owner put treatment plywood down touching the aluminum and that’s caused corrosion. Treated lumber and aluminum is a no,no.
Thanks for replying. I appreciate all the help I can get.
Screen Shot 2021-12-28 at 9.51.06 AM.png
1983 Monark 1652 / 1992. 3 cylinder 40 hp. Yamaha

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LDUBS
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Bunk boards

Post by LDUBS »

Douglasdzaster wrote: 28 Dec 2021, 18:27
As of now I’m still planning to change to flat 2x4s and adjust the brackets like you said. I was just hoping to go lower that 2”. I have some room between the fenders and tires that will let me move each one out a little wider and maybe then I can drop it lower. You’re correct about the front. That’s the second roller I’ve put on in a year. The boat must be pretty tough not to have dented. Took off some of the bottom coating though and scratched it good unloading.Tomorrow I’m getting a bracket that goes on the tongue and has a 2 foot 2x4 going cross ways. Then I can throw that roller in the trash. The boat doesn’t rest on the roller in the front. It helps load and unload.
I’m going to have to put off the bunks for a short time. Turns out I need a new floor I’m currently working on. I discovered the previous owner put treatment plywood down touching the aluminum and that’s caused corrosion. Treated lumber and aluminum is a no,no.
Thanks for replying. I appreciate all the help I can get.
Screen Shot 2021-12-28 at 9.51.06 AM.png

If there is enough clearance to move the fenders out without having to move the wheels, then life if good! I wanted a little more clearance on my current trailer, but unfortunately had no clearance between the wheels and fenders. I ended up adding wheel spacers so I could move the fenders out. It was only 3/4" on each side, but that is all I needed.
Have Rod - Will Fish

poorthang
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Bunk boards

Post by poorthang »

to make that trailer work, you would have to widen AND lengthen. then, it probably would still have issues with tracking, CG, spring rate, etc. you definately do not want to hang the boat past the bunks as you will create a hook in the bottom that will cause drag. not to mention cracks.

As already said, i would get another trailer. trailers are cheap, and you can sell your to someone to haul their ATV or mower.

eeshaw
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Bunk boards

Post by eeshaw »

I've got a 1650 flat bottom jon boat and for what you want to do, is exactly how I set mine up. I can stand in the boat and step out of it onto the floor in my garage. For what you're wanting to do you'd be time and money ahead to just get another trailer.