Converting from vertical 2x4 to horizontal 2x6 bunks

[HRG]

The new EZ Loader trailer that I'm buying (did not receive it yet) comes with bunk brackets that are 1.5 inches wide. The two 2x4 bunks are mounted vertically in the brackets so only 1.5" widths support the boat.

My boat is a flat bottom jon boat and I want two 2x6 bunks with the 5.5 inch width supporting the boat.

Has anyone here converted from vertical 2x4 bunks to horizontal 2x6 bunks? If so, how did you do it?

Thanks

 

[JimS123]

I never did it, so I can't help. My question, though, would be why? Many many boats riding on 1 1/2" wood, certainly many are a lot bigger than a Jon.

If it were me I'd add a set of keel rollers and call it a day. ()which is what I have done many times, including the 3 boats I currently own) The trailers they made years ago beat almost all of the ones today.

 

[Scott Danforth]

My fishing barge is nearly 65 years old and rides on its two original 2x4 bunks on edge that are only 3 feet long and 1 keel roller

The boat has been towed a minimum of 30,000 miles that I know of, usually full of camping gear and fire wood

Not sure what the issue is with your jon boat and why you think it's not sufficient

 

[flashback]

I agree with the above posts but if I wanted to do what you suggested I would just glue and screw the 2x6 on top of the 2x4..

 

[HRG]

I never did it, so I can't help. My question, though, would be why? Many many boats riding on 1 1/2" wood, certainly many are a lot bigger than a Jon.

If it were me I'd add a set of keel rollers and call it a day. ()which is what I have done many times, including the 3 boats I currently own) The trailers they made years ago beat almost all of the ones today.

It's a self-built wooden flat bottom jon boat that does not have a keel. Just a 3/8" thick plywood bottom with 5 frames. No V bottom on the boat for keel rollers.

Why? Googling "2x4 or 2x6 bunk boards", the general consensus was to go with flat 2x6 for better support. Plus I like the idea of more support area for my boat with only 2 bunks.

Thanks.

 

[HRG]

My fishing barge is nearly 65 years old and rides on its two original 2x4 bunks on edge that are only 3 feet long and 1 keel roller

The boat has been towed a minimum of 30,000 miles that I know of, usually full of camping gear and fire wood

Not sure what the issue is with your jon boat and why you think it's not sufficient

Wow, that is unreal. Only two 2x4x3' bunks on edge and one keel roller. Do those short bunks extend beyond the transom?

 

[HRG]

I agree with the above posts but if I wanted to do what you suggested I would just glue and screw the 2x6 on top of the 2x4..

That configuration is exactly what I was thinking about. But I was wondering if 5.5" wide bunk supported by 1.5" of a 2x4 on edge would work. Your suggestion pretty much confirms that it will work.

What do you think of this procedure:

1. Use pressure treated 2x4's and 2x6's, all 8 feet long.
2. Counter sink the 2x6 for 3/8" galvanized lag screws with galvanized washer.
3. Space the lag screws 16" apart.
4. When assembling, use thickened epoxy to glue the 2x6 on top of the 2x4.
5. After driving the lag screws home, fill the countersink with thickened epoxy to prevent salt water from pooling in the countersink holes.
6. Do you think I should fillet the 2x4 to 2x6 joint with thickened epoxy for more bearing area of the 2x4 holding up the 2x6?

Before mounting the two bunks, carpet them using stainless steel staples. Or would stainless steel roofing nails be better? Not sure how 1/2" long, 304 stainless steel staples will hold up in PT lumber and salt water. Not sure I can find 1/2" long, 316 stainless steel staples.

Thanks

 

[Scott Danforth]

Wow, that is unreal. Only two 2x4x3' bunks on edge and one keel roller. Do those short bunks extend beyond the transom?

from the transom to the first rib in the boat under the seat. where 80% of the weight of the boat is.

 

[Scott Danforth]

1. Use pressure treated 2x4's and 2x6's, all 8 feet long.
2. Counter sink the 2x6 for 3/8" galvanized lag screws with galvanized washer.
3. Space the lag screws 16" apart.
4. When assembling, use thickened epoxy to glue the 2x6 on top of the 2x4.
5. After driving the lag screws home, fill the countersink with thickened epoxy to prevent salt water from pooling in the countersink holes.
6. Do you think I should fillet the 2x4 to 2x6 joint with thickened epoxy for more bearing area of the 2x4 holding up the 2x6?

NO NO NO

NEVER EVER use pressure treated anywhere near aluminum

your in salt water. use cypres

 

[flashback]

That configuration is exactly what I was thinking about. But I was wondering if 5.5" wide bunk supported by 1.5" of a 2x4 on edge would work. Your suggestion pretty much confirms that it will work.

What do you think of this procedure:

1. Use pressure treated 2x4's and 2x6's, all 8 feet long.
2. Counter sink the 2x6 for 3/8" galvanized lag screws with galvanized washer.
3. Space the lag screws 16" apart.
4. When assembling, use thickened epoxy to glue the 2x6 on top of the 2x4.
5. After driving the lag screws home, fill the countersink with thickened epoxy to prevent salt water from pooling in the countersink holes.
6. Do you think I should fillet the 2x4 to 2x6 joint with thickened epoxy for more bearing area of the 2x4 holding up the 2x6?

Before mounting the two bunks, carpet them using stainless steel staples. Or would stainless steel roofing nails be better? Not sure how 1/2" long, 304 stainless steel staples will hold up in PT lumber and salt water. Not sure I can find 1/2" long, 316 stainless steel staples.

Thanks

I think your over engineering it a bit but it's your boat. fillet is not necessary IMO. and even using yellow pine lumber will last you many years, The PT lumber these days ain't what it used to be..

 

[JimS123]

It's a self-built wooden flat bottom jon boat that does not have a keel. Just a 3/8" thick plywood bottom with 5 frames. No V bottom on the boat for keel rollers.

Why? Googling "2x4 or 2x6 bunk boards", the general consensus was to go with flat 2x6 for better support. Plus I like the idea of more support area for my boat with only 2 bunks.

Thanks.

A protruding "keel" is not necessary to have keel rollers. In your case I would use flat rollers on every trailer crossmember. They will not only add more support, but you won't believe how easy the boat is to launch.

The Lyman in my signature has been riding on two 1 1/2" 3 foot long bunks for 70 years now. An that is a wooden boat as well. I'm sure it weighs considerably more than your jon.

Bottom line - yes 5.5 is better than 1.5, but its really not needed.

Just as an aside, if you built the boat yourself, it might be wise to add a center keel, or at the very least 2 side keels. Not necessarily for trailer-ability, but the boat will perform in the water better. As a former boat builder myself, that's what I would do.

 

[jimmbo]

The only trailers EZLoader puts bunks that narrow are very light trailers, 600 and 800 lb models, so even on edge, the weight per square inch isn't all that great. Trailers of greater Capacity will have longer and wider bunks

 

[HRG]

from the transom to the first rib in the boat under the seat. where 80% of the weight of the boat is.

Amazing to me as a first time boat trailer owner. Learn something new every day. Thanks.

 

[HRG]

NO NO NO

NEVER EVER use pressure treated anywhere near aluminum

your in salt water. use cypres

It's a self-built wooden jon boat, not aluminum. Trailer is galvanized. No cypress available in my area.

 

[HRG]

I think your over engineering it a bit but it's your boat. fillet is not necessary IMO. and even using yellow pine lumber will last you many years, The PT lumber these days ain't what it used to be..

I think you're right about fillets not being necessary. I'll just glue and screw.

I don't remember seeing untreated 2x4 or 2x6 pine lumber at Home Depot, Lowes or other local lumber stores in my area. Lots of treated lumber though. I have bought redwood and cedar 2x4's for fence building in the past so they are available. I don't see 2x6x8' cedar listed online for local HD or Lowes.

Also not sure if 1/2" stainless steel staples for the carpets will have holding power in cedar or if they will come off over time.

 

[HRG]

A protruding "keel" is not necessary to have keel rollers. In your case I would use flat rollers on every trailer crossmember. They will not only add more support, but you won't believe how easy the boat is to launch.

The Lyman in my signature has been riding on two 1 1/2" 3 foot long bunks for 70 years now. An that is a wooden boat as well. I'm sure it weighs considerably more than your jon.

Bottom line - yes 5.5 is better than 1.5, but its really not needed.

Just as an aside, if you built the boat yourself, it might be wise to add a center keel, or at the very least 2 side keels. Not necessarily for trailer-ability, but the boat will perform in the water better. As a former boat builder myself, that's what I would do.

Don't want small points of roller contact on the 3/8" plywood bottom of my jon boat. Trailer I bought is the cheapest EZ Loader trailer and it looks like this one:

.

.
My boat is already built and I'm painting it now. So adding keels are not an option for me. Thanks.

 

[HRG]

The only trailers EZLoader puts bunks that narrow are very light trailers, 600 and 800 lb models, so even on edge, the weight per square inch isn't all that great. Trailers of greater Capacity will have longer and wider bunks

Yes, it is a very light trailer. I posted a picture of the trailer in my response to JimS123.

 

[JimS123]

I suggest you put a pair of vertical roller style side guides on the back of the trailer. Otherwise it will be hard to center the boat when you retrieve it.

Tie Down Engineering Boat Loading Roller Guides

Heavy duty 2" roller with end caps. Length of roller is 9" Roller angle adjusts to angle of hull. One piece adjustable clamp with U-bolt. 16 inches of adjustment, 8" on both sides. Easy mounting, fits all channel and tube frames up to 5 inches. Hot galvanized steel...

www.iboats.com

 

[jimmbo]

It has more than ample Bunk Area for 600-800lbs

 

[JimS123]

Don't want small points of roller contact on the 3/8" plywood bottom of my jon boat.

My very first homemade boat was a 16' V-hull with an 80" beam. It ran with a 60 HP 2-stroke. The hull was 3/8" marine plywood. After a few years I pulled the motor and slid her off the trailer to repaint the bottom.

Not a sign of any dents or damage. Oh, that trailer had no carpeted wooden bunks - all little rollers.

Not trying to be argumentative. Just providing facts so that you can make a decision that you will be happy with.