Replacing trailer bunks

[LucG]

Hit the open water for the first time this year, and after a fairly successful day on the water, I damaged the completely rotten bunks on my trailer when loading the boat.

 

My question is what is the best wood to be using for replacements. The most common answer I am seeing is simple treated lumber. But I though I remember reading something about the chemicals and aluminium don’t mix, and could lead to corrosion to the hull. The other type of wood people suggest is cedar or marine grade but its a little expensive.

 

Any suggestions?

 

I plan on just wrapping them in some outdoor carpet or something similar

 

Thanks

[Fisherman]

Cedar, hard enough it won't damage and is naturally rot resistant.

[Lape0019]

These two pieces of wood are the only points of contact your boat has on the trailer. If you want to go cheap, I would find somewhere else to try and save money.

 

Preasure treated should work fine considering it will not be in direct contact with the aluminum. From what I have read, it seems there is only a reaction when the two are placed in direct contact. With the carpet there, you should be alright.

 

Other than that, Cedar would work, but I would lean towards the Marine Grade wood. Technically there is nothing special about this stuff either. It is not treated or anything. It is just made from another type of tree that resists mold and rot better than most.

 

I guess a third option would be to just buy reguler wood and coat it with something that would resist rot but this is a job I would want done right so that I didn't have to do it every year.

 

If the carpet is in good condition, you can always re use it. If not, go grab a 6 x 10 indoor outdoor matt and use that.

 

Adam

Edited May 15, 2013 by Lape0019

[SylvanOwner]

Anyone ever thought to try composite lumber? I have to replace my bunks as well and have been thinking this would be a rot-free solution.

[Lape0019]

Anyone ever thought to try composite lumber? I have to replace my bunks as well and have been thinking this would be a rot-free solution.

 

I have seen it installed on decks and it just seems a little too flimsy to be any good for that. It would be rot proof but I don't know if it would provide enough support for the boat. When installing decks, you have to put the joists closer to 12" on center instead of the standard 16" or 24.

 

My neighbor also has his dock bult out of the stuff and it is not supported well so it will sag in the middle down about 2 inches when I walk over them. I weigh 180lbs and to see that much sag over 3 feet would make me question using it for some twice as long and with only two supports holding it too the trailer.

[lew]

If you want to go cheap, I would find somewhere else to try and save money.

 

I agree, your bunks are a pretty important part of your rig and if one were to break while going down the highway it could end up nasty. Even the price of the best bunk product will only be a tiny fraction of the cost of your boat, motor and trailer.

[Luke V.]

Replaced mine this spring. Pressure treat lumber was used. Coated it 3 times is a clear sealer. Let it dry for 7 days to get good and hard. Covered with bunk carpet from marina added new brackets and bolts. And she will be good for another 10 years.

[fish_fishburn]

Pressure treated 2x4 tapered at the back where the boat slides on. Marine carpet with lots of stainlees steel staples dont cheap out on the staples put one every inch or even half inch. Also use new lag bolts as well.

[cityfisher]

Pressure treated 2x4 tapered at the back where the boat slides on. Marine carpet with lots of stainlees steel staples dont cheap out on the staples put one every inch or even half inch. Also use new lag bolts as well.

 

+1

[fishnsled]

I would personally never take a chance and use PT wood against my aluminum boat. I wouldn't trust any sealer and certainly not a porous carpet to keep those chemicals away from the hull. But that's just me.

 

The first set of bunks on my trailer lasted about 7 years and were just pine or spruce with carpet stapled onto them. I replaced them with the same, 4 years later and doing fine and no harsh chemicals again the hull. An easy enough job to do every few years and have some piece of mind. Just have the bunks ready to go and when at the launch just swap them out. X2 on lots of stainless steel staples to hold the carpet in place.

[Sinker]

Has anyone ever seen PT lumber react with aluminum?

 

I've had a PT floor in my boat for I'm guessing 8 years now. I call Bull on the whole PT/aluminum fiasco. Best floor my boat has ever had!

 

I also have PT bunks with carpet. No problem!

 

S.

[zamboniwaterboy]

http://www.easternmarine.com/loadrite-plastic-covered-bunk-1060-28-plh

[Lape0019]

http://www.easternmarine.com/loadrite-plastic-covered-bunk-1060-28-plh

 

That is a really good idea. No way the chemicals would ever touch the boat that way and probably not that much more expensive between the staples, carpet, and wood required to do it the normal way. Also less work putting it all together.

[bare foot wader]

i'm about to redo my bunks shortly, I managed to score some strips of leftover uhmw teflon, typically used on river sleds...pt lumber and countersunk screws, quick easy and should last a long, long time

 

puck board would probably be about the same, make loading shallow ramps easier too I would think and is easy to find/buy

[Fisherman]

Why anyone would use pressure treated is a little beyond me. Albeit the bunks may only be in the water for a short period of time, I really don't think immersing PT wood in the lake is a wise idea. Secondly, how deep into the wood do you think the actual PT goes? Maybe one mm. Cedar on the other hand has the natural oils to prevent rot and for the amount of time the bunks spend in water, I'd dare say the cedar will hold up as long as any PT'ed spruce or pine.

[irishfield]

Just an FYI... pressure treated no longer has cyanide in it and why it was a no no for floating docks (trailer bunks) in the past. The current wood technology isn't any more harmful than regular wood to water. That said... the new formulation is extremely detrimental to aluminum and even more so galvanized steel. Why all hanger brackets and post straps for decks have been changed to stainless. The PT will even eat regular screws.

[Fisherman]

Thanks for the info wayne.

[DRIFTER_016]

I would personally never take a chance and use PT wood against my aluminum boat. I wouldn't trust any sealer and certainly not a porous carpet to keep those chemicals away from the hull. But that's just me.

 

The first set of bunks on my trailer lasted about 7 years and were just pine or spruce with carpet stapled onto them. I replaced them with the same, 4 years later and doing fine and no harsh chemicals again the hull. An easy enough job to do every few years and have some piece of mind. Just have the bunks ready to go and when at the launch just swap them out. X2 on lots of stainless steel staples to hold the carpet in place.

 

My original bunks lasted 18 years. I replaced them a couple of years ago with spruce that I coated with 3 coats of polyurethane and then glued on my carpet and stapled with stainless staples. Should last me a long time.

 

It's not only the boat you have to worry about with PT lumber. The lag screws will fail pretty quickly due to the chemicals in the PT wood. Specially coated fasteners are used with that stuff. Unless you find some PT safe lag screws they will rot in a couple of years.

[Fish Farmer]

I re-did my bunks month and a half ago with 2X6 Spruce but I looked for good clear boards. That was the same wood that was on my Princecraft trailer but it had so many knots they just rotted, man what these companies just cover with carpet. The new carpet I used was a thicker plush pile. Now I have a hard time power loading or cranking the boat on because of the thick carpet. I'm looking for nylon kick boards from a arena to replace my carpet. I think the carpet holds water and rots the wood. They sell a kit that has a few pieces of nylon to go on your bunks that replace carpet. I think covering the whole bunk would be better than a few pieces, whole bunk, even support.

Edited May 16, 2013 by Fish Farmer