Bunk Boards

[jsmcobra201]

I have a 2015 Z9 that I bought new in 2015. After about 2.5 yrs of moderate use (1-2 weekends a month) my bunk boards are rotted. One of them was so rotted that the lag bolt is completely missing. I've already bought pressure treated lumber, cut them to size, and recovered them with carpet and the goal is to replace them all this weekend at the boat ramp.

Anyone else have this problem? I know bunks eventually will go bad, but I had my last boat for 12 years before I had to replace the bunks. Only 2.5 yrs seems a little soon for the boards to rot. My guess is that Tracker didn't use pressure treated lumber. I guess it was a cost saving decision.

[Fishysam]

I built, carpeted bunks and brought new hardware to the ramp like you in the past. That works well.

Let me add I HAVE HEARD YOU SHOULD NOT USE standard pressure treated lumber as this is THE MAIN REASON FOR BLISTERS, but i am not going to say that is correct or not,

but what i heard will last for anlong time is "cedar" or "KILN DRIED PRESSURE TREATED " as there is no chemicals going to blend with the water in the carpet

dont shoot the messanger. Just making sure you get to hear some information that may be super helpful.

[BMCD]

Yeah there is some reason they no longer use treated lumber, and galvanized lugs will cause rot in wood.

[nitro 90]

I replaced all of same on my 2010 Z-7.

[Wickedsmaht]

I hear some say they've replaced their with Ultimate Bunk Boards made out of high-density polyethelene plastic, and that they don't carpet over them.

[Sun Fish]

Yes, I had a 2013 Z9 that some of the first set of bunks rotting last season. I replaced the 2 at the ramp that rotted with new carpeted prrssure treated 2x4s. Unfortunately the boat was totaled in a road accident in October and when at the glass shop for repair estimates they showed me blistering unrelated to the accident from where the boat sat on the bunks. I would never have thought the boat had blisters being so new had the accident not happened. Im putting gatorbaks on my new boat before I even break the motor in.

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[einsteins]

I read the gator backs scratch the hull pretty bad.
I would think a synthetic board with carpeting might be wortha thought. Maybe cover gator back with carpet??

[Sun Fish]

I only read one situation where a guy had the scratching problem and gatorbak sent a rep out. I have friends locally that have used them for a few seasons with no issues at all. I figure if there is debris on your bunks carpet or synthetic it will scratch your hull either way but synthetic will not hold water and cause osmosis blisters. I'll be installing mine this week and for sure report back if I see them scratch the hull up unreasonably.

[Fishysam]

Problem with synthetic boards are they bend and flex a lot, eventually drooping, so if you could weld flat stock between supports to prevent them from breaking on a steep ramp

[jsmcobra201]

Bummer, I already got the pressure treated boards covered and ready to go. I've got a tournament next weekend so I've got to get it fixed now. I guess I'll use these for a while and look into gatorbacks or ultimate bunk boards in a couple months. The carpet I covered the boards with is supposed to not hold water, which I thought was the cause of blisters, but maybe there is something in the pressure treated lumber (chemical) that causes the blistering.

[Flippin 416]

Has anyone ever entertained or actually drilled some holes or used a router to cut some small grooves in the 2x4's before carpeting them? I know drilling holes would reduce the strength some but I'm not talking about putting 30 1/2" holes in them....just a few to help water drain and air to possibly move through/around them? I need to replace a few under my Z-9 and am toying with the ide of trying something like this.

[BigBadBass]

Even if you did holes, I would think the wood will still hold water and wick through carpet and thus cause blisters eventually on hull. The other materials other than carpet are a water proof barrier between that and wood and the groves then would be effective if on the waterproof material. I myself haven’t changed them out yet but have the Gatorbaks ordered but just can’t find untreated yellow pine here in the desert, just Douglas fir and that stuff bends like crazy. So hoping I don’t get blisters till I find a solution.

[Flippin 416]

Yeah I can agree with that. What about maybe sealing the boards before putting carpet on them....with some kind of varnish or shellac? I'm going to try something (just not sure what yet) when I replace mine since the first ones that need replaced are the smaller two up front.

[NCBC]

Even if you did holes, I would think the wood will still hold water and wick through carpet and thus cause blisters eventually on hull. The other materials other than carpet are a water proof barrier between that and wood and the groves then would be effective if on the waterproof material. I myself haven’t changed them out yet but have the Gatorbaks ordered but just can’t find untreated yellow pine here in the desert, just Douglas fir and that stuff bends like crazy. So hoping I don’t get blisters till I find a solution.

If you will check with Gatorbak, I replied to the order confirmation message, and ask about whether treated can be used under their product they will offer a ton of good info on this subject. I did not want to post it without their permission. Hope this helps.

[DixieChicken]

I wonder if letting the pressure treated dry a bit first might help. I know that how they do it now, vs how it USED to be done is entirely different.

I picked up boards, and carpet last Sept and was going to do mine while we were on vacation at Hartwell. Then the truck was so darned full I didn't have room for them.
I routed the edges of the boards, drilled and countersunk the bolt holes, and they've been sitting in the shop in the basement ever since. I know new PT lumber weeps for a while for sure.

Makes me think about whether or not to use a Brazilian hardwood. I built new decks in 2016 out of Ipe (eee-pay) wood. (Or Ironwood to us old guys.) This stuff isn't cheap, but it doesn't burn, doesn't rot, is insect resistant, is INCREDIBLLY DENSE @ 60lb per cubic foot, and will literally last 75~100 years. It's actually MUCH cheaper than the top of the line Trex or similar composite product. But it's really REALLY hard. (At the time, top of the line Trex was $60 a plank.

The decking boards, 144" x 3/4" x 5 3/8" were $44 (with grooved edged for hidden fasteners).

I haven't priced it compared to Ultimate boards, but I can ASSURE you it's less. Not normal to see it in 2x4 but it's out there. Probably in the $5 a foot range for Ipe.

Of course Ipe is the most expensive of the Brazilian hardwoods. There are many different ones, like Cumaru, Tigerwood, Purple Heart, Jatoba, Garapa..... and they are all better than pine or cedar for that matter. Massaranduba is a redwood, and likely would work great.

Think I might call my guy and check on that for my 'summer' project.

[jtrac]

I wonder if letting the pressure treated dry a bit first might help. I know that how they do it now, vs how it USED to be done is entirely different.

I picked up boards, and carpet last Sept and was going to do mine while we were on vacation at Hartwell. Then the truck was so darned full I didn't have room for them.
I routed the edges of the boards, drilled and countersunk the bolt holes, and they've been sitting in the shop in the basement ever since. I know new PT lumber weeps for a while for sure.

Makes me think about whether or not to use a Brazilian hardwood. I built new decks in 2016 out of Ipe (eee-pay) wood. (Or Ironwood to us old guys.) This stuff isn't cheap, but it doesn't burn, doesn't rot, is insect resistant, is INCREDIBLLY DENSE @ 60lb per cubic foot, and will literally last 75~100 years. It's actually MUCH cheaper than the top of the line Trex or similar composite product. But it's really REALLY hard. (At the time, top of the line Trex was $60 a plank.

The decking boards, 144" x 3/4" x 5 3/8" were $44 (with grooved edged for hidden fasteners).

I haven't priced it compared to Ultimate boards, but I can ASSURE you it's less. Not normal to see it in 2x4 but it's out there. Probably in the $5 a foot range for Ipe.

Of course Ipe is the most expensive of the Brazilian hardwoods. There are many different ones, like Cumaru, Tigerwood, Purple Heart, Jatoba, Garapa..... and they are all better than pine or cedar for that matter. Massaranduba is a redwood, and likely would work great.

Think I might call my guy and check on that for my 'summer' project.

Let us know what you find out. I'm wondering if the 3/4 boards could be glued and screwed together to make a 2 X 4. I know the glue would have to be waterproof.

[DixieChicken]

Let us know what you find out. I'm wondering if the 3/4 boards could be glued and screwed together to make a 2 X 4. I know the glue would have to be waterproof.

I'll try and ask them this week. I'm having to hang around the house tomorrow for sure, waiting on FedEx with my new 10' Blades!

FWIW, the supplier I use is Brazilian Wood Depot here just north of Atlanta. His entire yard is nothing but Brazilian hardwoods.

Any of those boards can also be bought with one side grooved, (with multiple U channels).

I wouldn't be surprised if the 3/4" board isn't strong enough on it's own. I mean this stuff is HARD. But it does come in bigger sizes, up to 4x4 for sure.

Naturally, left out in the sun it doesn't rot and still lasts a lifetime.... it just turns gray like teak. And teak, as we all know is THE wood for exposed areas on boats. On a deck it needs to be oiled at least once a year to keep it dark. I actually have alarms set in my calendar to remind me to oil it twice a year, at least for the first 5 years. With a 12 x 22 upper deck, one set of steps down to a 4x8 landing connected to a 12 x 18 lower deck with 180° set of steps off the bottom deck it takes a gallon of oil. Much easier than staining though as you just put it on with a latex paint pad on the end of a stick. Let it sit for 45~60 minutes then wipe it off like furniture polish.

My biggest problem (besides the cost) for the synthetic boards is they are TOO slick. Having to keep your boat hooked to the winch until it's in the water isn't something I've ever done, (and likely won't ever do). There's no way you can keep the back straps hooked till it's in the water, so the winch strap would be the only thing holding your boat on. I know some of the ramps we go to are freaking steep too! Could you IMAGINE what'd happen if the winch and/or strap failed?!?!!!!

Wonder how you'd explain that to your insurance company!

You: Hey guys.... uhhhhhh... well..... I was backing down this boat ramp and my boat slid off the trailer onto the concrete!
Them: Yeah RIIIIIIIGHT (followed by a room full of laughter, much similar to what you got on the boat ramp that day)
(Then in the background you'd hear the guy telling the underwriter to cancel your policy!)

[Fishysam]

Dixie, your wild, up here we have to keep the bow hooked up because the bunks are ice, nothing besides backing up at 10 and slamming the brakes will hurt the strap or winch if its tight.

A decade ago my dad got plastic pads to put on vs carpet, they stated you must leave hooked up and by golly you had better.... good thing he didnt touch the brake till the boat was wet.

I have also seen a boat on the concrete on its maiden voyage, im sure the insurance company has seen it as well, ps dont try and back up the truck while winching, wait for a crane

[jvanmeter]

If you will check with Gatorbak, I replied to the order confirmation message, and ask about whether treated can be used under their product they will offer a ton of good info on this subject. I did not want to post it without their permission. Hope this helps.

We are happy to share, Thank you NCBC

We get the question about bunk board replacement from quite a few of our customers during their bunk/trailer projects. The Key thing to keep in mind is that the trailer or lift is designed with a specific layout for supports, weight distribution, and bunk mounts. These lifting points take into consideration the bunk material span between them. Typically, most manufacturers us a Southern yellow pine (often treated) or a Pacific Northwest Douglas fir. These wood species have a specific strength (870 Janka Scale) that distributes the load across the lifting points by design. Other materials are in use but not on a wide spread scale due to the design criteria required. This is an important design feature for your boat. If the bunks are too hard then there may not be enough “spring” for a proper cradle of the hull and adversely, if it too soft there may be too much sag. Proper support and alignment of bunks can help with loading and unloading issues as well as trailering problems. By using the same species wood or a wood that is similar in hardness (Janka Wood Hardness scale) you will achieve an as close to designed fit and function as possible for your trailer or lift. IF your hull is not supported properly it may cause warping, or pressure spots. Please keep in mind this may affect your factory hull warranty.(depending on manufacturer)
The Question about using treated lumber and the safety of it for your hull’s sake is a good Question that we get from our Customers more often that you would think actually as well. Older types of Wood treatment chemicals used to be fairly caustic. This led to issues with accelerated corrosion of metals where they had contact with the treated wood. In the more recent years these older formulas have been changed out with more environmentally friendly components. This has lessened these effect quite a bit. As you can imagine we visit with so many boat trailer builders it’s difficult not to pick up on industry trends. Most trailer manufacturers are using Yellawood or Georgia pacific products. We tend to see Yellawood more often. There are different levels of treatment. Ground contact, exterior above ground and even Marine grade. Keep in mind these treatments are all about wood boring insects, organisms and are specific for the environment they are applied (on the ground, exterior or in water)
Hardware is also a frequent question. When dissimilar materials are combined barrier materials can be used to lessen the reactions between them. Use of Automotive butyl products can be used to separate your bunk boards from the mounts as well. Automotive Butyl is a non-commercial name for products such as Kilmat, or Dynamat. These are used as sound deadeners in the floor of your vehicle to dampen road noise and vibration. Also keep in mind there are differences in grades for hardware. We have found that 316 Stainless is the best for neutrality, but, there are many choices and they will have different price points in accordance to quality.
Proper support and alignment of bunks can help with loading and unloading issues as well as trailering problems. If you would like a sample of Gatorbak Synthetic bunk Cover please let me know and we will be glad to get one to you so you can see it firsthand. Making a decision about upgrading your bunks is important. We would like to offer any help we can provide.