Are these trailer bunks correctly positioned for a jon boat?

[Jogar80]

This past December I got myself an 1982 lowe 1648 to go duck hunting with my 8 yr old boy. Paying a guide $500 per trip wasn't sustainable, and a new boat isn’t feasible for us peasants, so fixer-upper it is. I’ve focusing on the boat., but with so much work i’m putting into it, I want to make sure the trailer is right. It is definitely solid but I’m going to carpet the bunks. Also wondering if the bunks are in the ideal position/configuration for this type of boat. Here’s some pics. The boards on the bottom are standing on edge, as well as the front block. Don’t mind all the JB Marine Weld on the rivets

 

[FuzzyGrub]

Pictures can be deceiving, but a few things I would look at doing:

- The trailer itself looks very narrow for the boat. It looks like tires may contact the boat if the springs compressed far enough. The axle is already under the springs, so will have to raise the bunks some, if that is the case. Launching the boat will require backing in further at the ramp.

- The bunks should be evenly spaced and contact the boat on their flat edge. They look like they are slightly angled and are contacting on the sharp edge. The bunks should run along the strakes where the hull is stronger. Not sure if you have room to go to the outside of the strakes with the wheel clearance. The inside would be 2nd choice. Also helps keep hull from sliding sideways on trailer.

-That front wood support is going to damage the boat. Replace with rubber or urathane roller.

- Not sure if you can fit any fenders, but the tires will shed dirt and stones that may damage hull.

- I couldn't tell from the pictures, but the bunks should extend just past the transom, so you don't put a "hook" in the hull.

 

[airshot]

Agree with everything fuzzygrub stated !! In most states, fenders are required as anything coming off those tires is the owners responsibility. If your towing with the weight of an outboard or heavy battery in the rear then those supports need to go all the way to the transom for support or the hull will be damaged. Feel free to add more supports or make them longer, can't have to much support ! Check your tongue weight after loaded, should be 10% of total weight of loaded trailer or you will create some serious sway going down rhe road !

 

[Jogar80]

Fuzzygrub, thanks so much for your input. Are you saying to raise the bunks on the sides or bottom of the hull? I would prefer not to have to back the trailer in further as im pretty scared of boat ramps in general I never know if there’s some drop-off the trailer is going to fall off of.

You are saying the the wider side of the bottom boards are the ones that should be contacting the bottom of hull and they should be longer to extend further back than the transom, correct? Or is it ok the the boat rests on the 2” side of 2x4 but just make sure they are straight?

Also replace wooden front support with a roller and add fenders if possible.

And…. What are strakes? I didn’t understand the part about moving bunks outside strakes. Do the bunks along the outside of hull look ok?

Thanks again I really need the help!

 

[Jogar80]

Agree with everything fuzzygrub stated !! In most states, fenders are required as anything coming off those tires is the owners responsibility. If your towing with the weight of an outboard or heavy battery in the rear then those supports need to go all the way to the transom for support or the hull will be damaged. Feel free to add more supports or make them longer, can't have to much support ! Check your tongue weight after loaded, should be 10% of total weight of loaded trailer or you will create some serious sway going down rhe road !

Thank you AirShot, this is all new to me and every bit of information and suggestion is very appreciated.

 

[FuzzyGrub]

Fuzzygrub, thanks so much for your input. Are you saying to raise the bunks on the sides or bottom of the hull? I would prefer not to have to back the trailer in further as im pretty scared of boat ramps in general I never know if there’s some drop-off the trailer is going to fall off of.

Your bunk brackets look like they have allot more verticle adjustment. Raise both of the brackets on each bunk to get more clearance. You will also want to raise that new front roller to keep the boat near level.

You are saying the the wider side of the bottom boards are the ones that should be contacting the bottom of hull and they should be longer to extend further back than the transom, correct? Or is it ok the the boat rests on the 2” side of 2x4 but just make sure they are straight?

The narrow side of the 2x4 is fine. You just want it as flat as possible to the hull. There will be some tilt adjustment within the bracket. Regardless of bunk width, you want them to the end of the transom. You could lay them flat to get some additional support, but will require four new brackets.

Also replace wooden front support with a roller and add fenders if possible.

And…. What are strakes? I didn’t understand the part about moving bunks outside strakes. Do the bunks along the outside of hull look ok?

The bottom ribs. You want the bunks close to them for the hull is stronger there. If there is room to have them on the outside of the rib, it will provvide slightly more stability.

Thanks again I really need the help!

Hope that helps.

 

[FuzzyGrub]

Agree with everything fuzzygrub stated !!

You say that like it was an unusaul event!

 

[Jogar80]

Your bunk brackets look like they have allot more verticle adjustment. Raise both of the brackets on each bunk to get more clearance. You will also want to raise that new front roller to keep the boat near level.


The narrow side of the 2x4 is fine. You just want it as flat as possible to the hull. There will be some tilt adjustment within the bracket. Regardless of bunk width, you want them to the end of the transom. You could lay them flat to get some additional support, but will require four new brackets.

The bottom ribs. You want the bunks close to them for the hull is stronger there. If there is room to have them on the outside of the rib, it will provvide slightly more stability.

Hope that helps.

Thank you!

 

[gillhunter]

The bunks should protrude pass the transom or you will "hook" the hull. Don't use treated lumber.

 

[Bantou]

That front wood support is going to damage the boat. Replace with rubber or urathane roller.

Looking at new haul master trailers for flat bottom jons, it looks like they have a 2x4x3’ turned horizontal to the trailer with the 4” side up instead of a front roller.

I was planning on doing the same thing since my roller was designed for either a “v” or mod-v hull. Is that going to cause an issue or will it be ok?

 

[FuzzyGrub]

Maybe it just the pictures, but your boat doesn't look flat at the roller. Also looks like the center rib is deformed near the roller. Looks like the center rib would take all the weight. If it is contacting multiple ribs, than that might be OK. When it is winched up, maybe it is not touching that 2x4?

FWIW: Our relatively new trailer that came with our flatbottom G3, just has long stationary bunks. 2x4s, laying flat with a plastic cover. About 7'-8' long. No front roller, but it doesnt have a center beam to the trailer that the rib could hit.

 

[Bantou]

Maybe it just the pictures, but your boat doesn't look flat at the roller. Also looks like the center rib is deformed near the roller. Looks like the center rib would take all the weight. If it is contacting multiple ribs, than that might be OK. When it is winched up, maybe it is not touching that 2x4?

FWIW: Our relatively new trailer that came with our flatbottom G3, just has long stationary bunks. 2x4s, laying flat with a plastic cover. About 7'-8' long. No front roller, but it doesnt have a center beam to the trailer that the rib could hit.

I think it’s because I used the wide angle feature on my phone. I haven’t put a board across it, but it looks flat to the naked eye. I suspect it is going to need some support up front. Even with 10’ 2x4s, that would leave about 6’ just floating over the trailer center beam.

 

[Jogar80]

I think it’s because I used the wide angle feature on my phone. I haven’t put a board across it, but it looks flat to the naked eye. I suspect it is going to need some support up front. Even with 10’ 2x4s, that would leave about 6’ just floating over the trailer center beam.

I’m no help here, just curious about your setup and why I can’t see your pictures?

 

[Bantou]

I’m no help here, just curious about your setup and why I can’t see your pictures?

They are on a Different thread. The trailer looks like a haul-rite EC600, which is designed for some form of V hull. Their flat bottom jon trailers are the ones with the horizontal 2x4 instead of rollers

 

[Jogar80]

The bunks should protrude pass the transom or you will "hook" the hull. Don't use treated lumber.

I now understand why treated lumber is not recommended for aluminum boats. I wonder if some plastic slides on the contact surface would allow for use of treated lumber. I only ask because i fear wood rot will be an issue more quickly if I dont use treated lumber.

I mean something like this:

 

[Bantou]

I now understand why treated lumber is not recommended for aluminum boats. I wonder if some plastic slides on the contact surface would allow for use of treated lumber. I only ask because i fear wood rot will be an issue more quickly if I dont use treated lumber.

I mean something like this:

You’ll be fine with non-treated lumber as long as you give it a way to dry out. Marine grade carpet is designed to dry quickly and will allow the bunks to dry out underneath as well. If you don’t want to go the carpet route, there have been several guys on here that used either vinyl fence post cut in half or vinyl gutter for runners.

I’m probably going to use pvc roofing material for mine. It’s slick as ice when wet a just slightly tacky when dry. Figure it will make for good runner material and I have it on hand. Just have to make sure and leave the bottoms open so that the bunks can dry.

 

[Stand Up]

I now understand why treated lumber is not recommended for aluminum boats. I wonder if some plastic slides on the contact surface would allow for use of treated lumber. I only ask because i fear wood rot will be an issue more quickly if I dont use treated lumber.

I mean something like this:

The problem with the plastic slide material is that it will trap water and cause rot. Not a big deal as you can replace bunks cheaply.
For bunk material just use spruce lumber. Spruce will last a long time if it's allowed to dry and it will dry because the trailer is parked out of water. Cover the spruce with bunk carpet and you're good to go. Don't overthink this.

 

[Bantou]

The problem with the plastic slide material is that it will trap water and cause rot. Not a big deal as you can replace bunks cheaply.
For bunk material just use spruce lumber. Spruce will last a long time if it's allowed to dry and it will dry because the trailer is parked out of water. Cover the spruce with bunk carpet and you're good to go. Don't overthink this.

Spruce is plain dimensional lumber right? Where I’m at, spruce boards are all finish grade and about 2x the cost of Southern Yellow Pine framing lumber.

 

[thill]

Most here prefer cedar or cypress, but it's expensive.

I've used a pressure treated wood that doesn't react with aluminum under marine carpet for many years under my bare aluminum hull with no issues.

You have to find the brand and check the literature and data sheet before choosing PT wood for your bunks. The associates at the big box stores probably don't actually know.

 

[Stand Up]

Spruce is plain dimensional lumber right? Where I’m at, spruce boards are all finish grade and about 2x the cost of Southern Yellow Pine framing lumber.

That's correct. 2" x 4" material. You can use the Yellow pine and if it only lasts 5 years or so, not a big deal. Easy to replace the bunks.