Lifting boat off trailer to repair bunk

[ryno1234]

I have a bunk that, as of last night, decided to completely detach itself from the trailer while launching. I had to get in the water and sandwich the bunk between the boat and the trailer as someone pulled the boat out of the water.

Needless to say, I need to repair this ASAP.

I've picked up new lag bolts (same size, length, etc.)

As I see it, I have 2 immediate options:

1. Repair the bunk while the boat is on it
2. Repair the bunk while the boat is in the water

The 2nd option is harder because I'm probably going to go to the water with family / friends and don't want them to wait on me while I do repair duty in the parking lot of a launch. Additionally, if I reuse the existing bunk, I'd plan on using RTV or Liquid Nails to fill the bolt holes prior to sinking new lag bolts when I re-secure the existing bunk. With wet bunks after dropping my boat in the water, I'm not sure if that would inhibit the long term curing of those adhesives.

If I can fix this at home, that's ideal (but am prepared to fix it at a launch if that's necessary)

Is there a way to reasonably lift 1 side of the boat just enough to get my broken bunk board out without damaging the boat? I've never lifted a boat off a trailer and want to be very cautious to both the trailer and the boat.

I have a 1997 Maxum 2400 (roughly 7-8K lbs loaded)

Thanks!

 

[Scott Danforth]

2x6, 2 jack stands, a bottle jack and floor jack

Use the 2x6 between the hull, jack up off trailer and put jack stands under.

 

[jimmbo]

While RTV has no structural Strength, moisture actually accelerates the Curing Process. Epoxy might be a better material to use to fill in the old holes, and can even be used to secure the Lag Screws if you want to use the same holes

 

[ryno1234]

While RTV has no structural Strength, moisture actually accelerates the Curing Process. Epoxy might be a better material to use to fill in the old holes, and can even be used to secure the Lag Screws if you want to use the same holes

The point with the RTV was to prevent the bolts from backing out. Good point on the moisture!

Ultimately all my bunks need to be replaced in a much larger effort.

 

[Scott Danforth]

The point with the RTV was to prevent the bolts from backing out. Good point on the moisture!

Ultimately all my bunks need to be replaced in a much larger effort.

RTV is useless to prevent bolts from backing out.

rust will take care of that. even the 18-8 stainless lag bolts will rust. I suggest just galvanized

 

[flashback]

Gather you parts for the trailer, put the boat back in the water, fix the trailer..

 

[airshot]

I would never use lag bolts for a bunk. Go with a carridge bolt ( rounded head) and add a nut on the outside. A couple jam nuts will lock the bolt in place and keep it there even if the wood swells and shrinks. If your wood has become soft why not just replace the entire bunk or bunks then your good for a long time. Make up your new bunks, gather your hardware and a drill. Put the boat in the water and have your friends give you a hand while they wait, wont take that long...trying to cobble the old one will take longer and wont last....

 

[harringtondav]

I replaced the bunks on my previous trailer with the boat on the trailer. I used a floor jack with a 2x4 under the keel with jack stands between the chine and trailer. I kept one tie down strap connected so the boat would lift and tilt away from one bunk at a time. ...it took a little trial and error to get the jack centered fore-aft.
Also I used SS elevator bolts. The heads mash into the bunk wood flush so they don't protrude through the carpet and guff your hull. Link attached.
...I found some with a hex wrench drive but can't find the link.

Bolt Depot - Elevator bolts, Stainless steel 18-8

www.boltdepot.com

I found these, maybe what I bought 5/16-18 thread.

https://www.grainger.com/product/61JL30?gucid=N:N:PS:Paid:GGL:CSM-2295:4P7A1P:20501231&gclid=Cj0KCQjwhY-aBhCUARIsALNIC04JKIbVqXOM5w83TbdQiz6OFjCtWaHIrFCyt0TA9elBddtTt9QJh6UaAgRJEALw_wcB&gclsrc=aw.ds

 

[JASinIL2006]

If you just want to lift it off the bunks to replace it, four bottle jacks and pieces of 2x6 between the jack and boat will do the trick. When I rehabbed and painted my trailer, I built a v-shaped cradle out of 2x4s to support the keel near the bow and used jack stands (with 2x6s) to support the stern. It was quite stable and the boat hung out on the stands for a couple of weeks while I worked on the trailer. If you're thinking of replacing all the bunks, it might be worth it to get the boat totally off the trailer for a while.

 

[briangcc]

Me...I'd get the replacement bunks ready to go, launch it, and do the repair work in the parking lot. Probably 15-20 minutes provided you plan ahead.

Rip old off, replace with new, bolt on and you're gtg.

 

[ryno1234]

Me...I'd get the replacement bunks ready to go, launch it, and do the repair work in the parking lot. Probably 15-20 minutes provided you plan ahead.

Rip old off, replace with new, bolt on and you're gtg.

I think this is what I'm leaning towards more and more. I'm just going to have to ask the entourage to be patient I'll feed them drinks while I do the work

 

[Scott Danforth]

if the old bunk is secure and there is no chance of the brackets puncturing the hull, then work on it at the ramp.

however I have witnessed too many hull breaches from bunk brackets to not change the bunks while the boat is on the trailer.

just my $0.02 YMMV

 

[poconojoe]

I recently replaced my 4 bunks while my 18.5 ft. bow rider was in my driveway.

I thought about preparing the new ones and doing it in the parking lot at the boat ramp, but worried that there would be complications or I would need specific tools that I may not have brought with me. Seemed too much could go wrong and if I couldn't get it done and I was stuck without a bunk, then what?

I did one at a time.
Jacking it up with bottle jacks and lots of long pieces lumber positioned at strong points of the hull, mostly the corners of the transom, spreading out the weight.

I not only jacked it up each time, but also supported it with jack stands while working on the bunks. I never trust a jack alone. I always use a jack stand along with a jack.

It took lots of scrap lumber to get it jacked up right each time.
I think the main thing is to spread the weight out in the proper areas of the hull for best support.

I replaced all 4 bunks in an afternoon.
Two of the original ones from 2003 were literally disintegrated. Only the carpet was holding them together!

I was lucky with the carpet. I was able to reuse all of it.

My bunks were originally mounted with lag bolts and they lasted 19 years.
It's a Karavan trailer.
I replaced the lag bolts since most of the old ones were rusted and the treads were almost gone.

I used a lot of different tools, both hand tools and power tools.
I'm glad I did it in my driveway.

It really wasn't that difficult. You just need to support the boat properly, releasing only one stern strap at a time. I also lowered the tongue jack so the weight of the boat was shifted a bit toward the bow.

 

[ryno1234]

UPDATE: I replaced the bunks yesterday.

I prepared them in my garage ahead of time with an important step: I made sure that the carpet on the backside of the bunk around where the lag bolts would go in was cut back nearer to the edge of the board so not to interfere / twist the carpet when trying to sink the lags.

I did 4 bunks for a total of 30 lags for removal and 30 lags for installation and did it in 20 minutes. It (almost) couldn't have gone any smoother.

Luckily I had 3 person team to assist:

• One person using a cordless impact gun to sink the lags
• One person lining up the bunk and sitting on it to keep pressure against the mount
• One person fetching and assembling a lock washer / washer / lag and handing it to me.

This went super quick.

The only thing I didn't consider was the fact that I'd need a way to get the old and now soaking wet bunks (since I just dropped my boat in the water) bunks back home for disposal.

Might want to consider a cordless saw to cut them up, or straps so you can secure them in the bed of your truck, etc.

 

[harringtondav]

Luckily I had 3 person team to assist:

Lucky you. The only way I can round up three people is to have them assist drinking up my beer.

 

[poconojoe]

Great teamwork!

 

[kep5niner]

UPDATE: I replaced the bunks yesterday.

I prepared them in my garage ahead of time with an important step: I made sure that the carpet on the backside of the bunk around where the lag bolts would go in was cut back nearer to the edge of the board so not to interfere / twist the carpet when trying to sink the lags.

I did 4 bunks for a total of 30 lags for removal and 30 lags for installation and did it in 20 minutes. It (almost) couldn't have gone any smoother.

Luckily I had 3 person team to assist:

• One person using a cordless impact gun to sink the lags
• One person lining up the bunk and sitting on it to keep pressure against the mount
• One person fetching and assembling a lock washer / washer / lag and handing it to me.

This went super quick.

The only thing I didn't consider was the fact that I'd need a way to get the old and now soaking wet bunks (since I just dropped my boat in the water) bunks back home for disposal.

Might want to consider a cordless saw to cut them up, or straps so you can secure them in the bed of your truck, etc.

I’ve done this exact process on no less than 3 trailers I’ve owned. Plan ahead. Cedar bunks and marine carpet attached with Monel staples, secured with galvanized bolts was is the process I use. Nice job.

 

[HRG]

UPDATE: I replaced the bunks yesterday.
The only thing I didn't consider was the fact that I'd need a way to get the old and now soaking wet bunks (since I just dropped my boat in the water) bunks back home for disposal.

Might want to consider a cordless saw to cut them up, or straps so you can secure them in the bed of your truck, etc.

So to complete your update, what was your solution for the soaking wet bunks? Just curious for the end of the story.

 

[ryno1234]

So to complete your update, what was your solution for the soaking wet bunks? Just curious for the end of the story.

Not my shining moment here: we had no way to getting them home, so we set them aside at the boat ramp on the river bank. I came back the next morning with a skill saw and they were gone by 9:30am. We got off the water around 8pm the night before... so just over 13 hours.

I live outside of Sacramento and we launched at a Sacramento launch. Unfortunately there are many homeless, especially on the river banks, and I wouldn't be surprised if they took them given the speed at which they disappeared.

 

[HRG]

Not my shining moment here: we had no way to getting them home, so we set them aside at the boat ramp on the river bank. I came back the next morning with a skill saw and they were gone by 9:30am. We got off the water around 8pm the night before... so just over 13 hours.

I live outside of Sacramento and we launched at a Sacramento launch. Unfortunately there are many homeless, especially on the river banks, and I wouldn't be surprised if they took them given the speed at which they disappeared.

A good ending. Win for you and a win for whoever wanted and took the bunks. Thanks for the ending of the story.