Jacking up my boat part way to replace a bunk board.

[jcsmith77]

I have discovered my port side rear bunk board is falling apart and i fear that if i try to trailer it back to water to get the boat off, it will completely fail and i will be sitting on the steel support. So is it safe for the hull to jack up the rear of the boat so that i can replace that bunk board? I was thinking a floor jack with a cross beam attachment at the rear with some plywood to possibly get better weight distribution. Anyone have any advice?

 

[itsdgm]

I think @CrankyGypsy has some experience with that. Check out this thread for some pics https://jetboaters.net/threads/how-to-beginner-frp-repair-in-the-driveway.8184/#post-141447

Hopefully he'll chime in soon and give some pointers. He's great at documenting the work that he's taken on.

 

[Andy S]

I have discovered my port side rear bunk board is falling apart and i fear that if i try to trailer it back to water to get the boat off, it will completely fail and i will be sitting on the steel support. So is it safe for the hull to jack up the rear of the boat so that i can replace that bunk board? I was thinking a floor jack with a cross beam attachment at the rear with some plywood to possibly get better weight distribution. Anyone have any advice?

I have jacked my boat exactly the way you are talking about. To get the jack close enough to the hull I put the jack on cinder blocks. I positioned the jack and blocking under the hull at the very aft part, under the transom drain. Prior to lifting the boat, I also connected the trailer to my truck to help stabilize the trailer while lifting the boat. While lifting and lowering I went very slowly to minimize the amount of pressure on the hull which work because there was no damage from lifting.

 

[CrankyGypsy]

another option is to lower the tongue all the way to the ground. then you can stack cinder blocks on both sides - place them under the horizontal surface below the black on your boat. then raise the tongue back up - the boat will sit on the blocks, rather than the rear bunks.

 

[Bruce]

I do not understand how the bunk coming off as the boats goes into the water would be a problem. Would the boat not be floating when the bunk came off?

 

[jawsf16]

Sounds like he is worried about the trailer ride to the water...

 

[BlacklimitedS]

I agree with Bruce. Unloading your boat in the water and fixing the bunk is much safer than jacking it up. Just back up deeper in the water and the boat will float off. While you can jack your boat up things can go wrong quickly.

 

[BlacklimitedS]

Sorry I misunderstood the original question. I still think the weight of the boat will keep things together for a short trip to the lake.

 

[jawsf16]

Find the nearest lake with a ramp. When I did my UBB install we went to a tiny lake five minutes away that you really wouldn't use our boat on but it was enough to float off while I worked on the bunks.

 

[buckbuck]

I sent my wife and daughter out into the river and did mine in the parking lot.

 

[Julian]

I would think that if the lag bolts are still in the bunk boards it would be unlikely the bunk would disintegrate on the way to the ramp (depending on how long and how bumpy the ride to the ramp is).

 

[jcsmith77]

The problem is that the board is already almost completely gone. And yes my fear is the ride to get there and the lag or stel support jabbing a hole in the bottom. So 30-45 minute trip over crappy missouri roads to the nearest ramp makes me really nervous.

 

[Bruce]

I see that the bottom of the board is coming apart. Is the rest of it soft?

 

[jcsmith77]

Because of the weight of the boat, i couldn't just peel it away with my fingers like the bottom, but its definitely in very poor condition as well. I am thinking I may try to jack and take some of the weight off of it and see what i am dealing with and if nothing else get a temporary support in there to make it to the water. It jacks up easy, I will just replace it. I was really shocked at how poor of condition it was in.

 

[PEARCE]

What I would do is back the lag bolts out first. I would then make sure the boat is tied down to the trailer good and snug so it wouldn't bounce around on the bunks. I would then take a slow and careful cruise to the nearest ramp missing as many potholes as possible. Before you leave for the ramp make sure you have your boat keys, needed tools and materials, and a cooler of your favorite adult beverage. You'll probably need your first one once you get to the ramp. Have another after you launch and come back after doing a few spins. Get the chore done and have another if you want to celebrate a job well done. Let us know how it works out!

 

[CrankyGypsy]

this is silly: he is telling us that he's not sure it will hold up. yet he's still being advised to not only risk damage to the boat, but to put anyone else on the road at risk by transporting it. not to mention, he would also be removing the project from his property where additional tools are located, which could put the repair in a bind should something unexpected arise.

trust me, the method I described is the best option ...i am unclear how this is "unsafe" in comparison - if by some micro-small chance it comes off the blocks, it will fall ~1" onto the bunks. in my photo above, there are several jack points, but you only need the back two on each side for this job. I had additional jacks because I was doing a hull repair over several weeks.

 

[BlacklimitedS]

I agree with @PEARCE. The end of the bunk does look bad. This is most likely due to the boat hitting the bunk when centering itself on the trailer. Bottom line it is ultimately your call. By looking at your pics you are not endangering any humans or wide life by towing to the lake. That damage did not happen overnight and I would bet you have towed many miles with the bunks in poor condition. There is much more than a "micro chance" of things going wrong when you jack your boat off the trailer. Best of luck with the repair either way.

 

[jcsmith77]

After closer inspection, one of the lags is already gone and the other is actually being pushed back through the metal brace because the board is compressing. Since this is the first year of owning the boat, it did take a trip to and from my lake of choice, however, I think I have reached that critical point where there isn't enough left to support it.

Honestly the whole boat sits on 4 boards on 8 braces. If i spread the weight over a wide enough area, I really think that jacking it up a few inches or doing as @CrankyGypsy prescribed to pull the board out and replace it offers significantly less risk to the hull of the boat. If it were the front middle boards i might be more inclined as it would seem to be harder to find a spot to jack and support.

I have to order the staples and wait for our weather to not suck before i tackle it but i will report back on how it goes or if I completely screw it up.

On another note, anyone have any idea why i only get notified sometimes when someone replies to the thread? and thanks for everyone's input.

 

[jcsmith77]

So i finally got around to trying all this out. I used a piece of 4x6 i had laying around and cut wedges at a 20 degree angle to match the hull at the back and positioned them as best i could and screwed them down. Then I loosed everything up and jacked up the back a few inches. This definitely created some downward pressure on the front roller, but I got enough to get it out and get the new one back in. I had originally intended to reuse the carpet but that idea went out the window pretty quickly and made a run to homedepot for the best option they had. I would have preferred something like i had seen from ebay in the other threads but I didn't want to leave the boat in the air for a week. So the bad bunk has been replaced and i checked the others while i was under there and they are not as bad, so they will be changed when i launch the boat the first time this year. For the record, I used treated lumber with a coating of some water based sealer i had laying around, stainless 1/4 crown staples and bought some new stainless lags, ouch on those.

.

 

[jawsf16]

Based on that last pic you are lucky the boards didn't simply disintegrate sitting in the driveway! Good work!