cutting partial stringer and adding 2 bulkheads

[Redrig]

Hey everyone,

I am looking to add a ski locker to my boat , I just have absolutely no storage in her. today I did some exploratory surgery on her to find out what I had under the deck

I was hoping that I only had 2 stringers , running forward from the motor mounts. It turns out that I have 3, 2 for the motor mounts and one the other is dead center.

there is a massive area in there that would be great to add a ski locker in there.

do you think I am OK to cut part of that middle stringer and then add 2 bulkheads (3/4 ply) in the area for my ski locker ? basically use these bulkheads to tie into the port and starboard stringers ? it would be about 4 feet of the stringer I would be cutting out.

Thanks fellas

 

[Redrig]

This is something along the lines of what I am thinking. Thoughts ?

Green Lines will be the Bulkheads I will be adding , and I will even go up the sides to reinforce and tie it all together. I will use 3/4 ply , like whats in there now.

Red is ski locker.

 

[JASinIL2006]

I imagine others with more experience will chime in soon, but I'd be concerned about cutting the center stringer. Seems like that is a pretty important part of the boat's structure.

 

[Woodonglass]

If you do a good job of grinding and glassing, I don't think the hull will suffer any catastrophic failure from your modifications.

 

[Redrig]

thanks for the responses fellas.

JA - Thats why I am asking around before doing anything , I have seen alot of threads on rebuilds where boats only have the 2 stringers , with the gas tank in the middle . mine having this middle stringer changes my inital plans .

WOG - I did some griding and cutting this weekend , that is not fun at all. I have been researching lots of threads here and you guys make it look so easy.

After thinking about it further , I can be sold on this layout below, I think I will go this route , it will be a little more $ but less work , and seems safer. we dont need to be bringing even the potential for a "catastrophic failure" into the equation.

with this layout , I wont touch the stringer and just add the 2 bulkheads , then use the hatch doors for acces.



using 2 of these deck hatches of this variety.

http://www.iboats.com/Beckson-14x24-...FZWIaQodXkEAqw

I just worry about the strength and profile of those , these will be located in a high traffic area, and dont want to tripping over them. but , if its safer we can learn to deal with it.

 

[JASinIL2006]

No Title

I'd be inclined to try to find something like this. Slightly lower profile, less of a tripping hazard....

 

[Redrig]

I'd be inclined to try to find something like this. Slightly lower profile, less of a tripping hazard....

that was exactly the original plan right there , put one of those in the middle.

The problem is now though , without cutting the stringer , I need to really limit the size of the opening .

most of those type hatches are 36" long , and If I am running 2 of them like the illustration above , one on each side of the middle stringer I cant go up to 36" because of the seat bases. something like that in a 15 x 20 ish would be ideal.

 

[Woodonglass]

As long as the center stringer is attached to the bulkead as shown in your drawing and you're only removing about a 3ft section, I seriously doubt you'll be putting the hulls structural integrity in any danger. The rest of the "Keel" is in place and the span between the Bulkeads and the other stringers will do the job nicely. IF you want to be more than safe, then lay down a couple of layers of 1708 on the bottom of the "Ski Locker" to bulk up the hull in that area and I assure you that you'll have NO ISSUES whatsoever with your modification.

 

[kcassells]

Is the center stringer full height? Meaning full height from hull to underside of floor or is it a keel? On another note wog is more than likely correct. On my boat the stringers were cut down from 18" to 2" by the mfg to allow port and starboard 48" wells/storage below deck.
Either way will work.

 

[Redrig]

while searchin , I came across this thread.

http://forums.iboats.com/forum/gene...-that-is-primarily-a-square-or-oval-ring-with

Does anyone know a source for these trim rings ? Then I can just fill with my own King Starboard or teak ,whatever.

one of these would be ideal.

 

[Redrig]

Is the center stringer full height? Meaning full height from hull to underside of floor or is it a keel? On another note wog is more than likely correct. On my boat the stringers were cut down from 18" to 2" by the mfg to allow port and starboard 48" wells/storage below deck.
Either way will work.

I have only cut back about 6 inches forward of the bilge / engine area .

at that location the center stringer is 12.5 from the bottom of the deck to where it connects to the hull. not sure if that answers your question or not.

but looking at the hull shape , it is a deep V hull and looks to remain at that same depth for probably 10 feet before it starts rising towards the bow .

 

[Woodonglass]

Or you could buy this on ebay...http://www.ebay.com/itm/RUNABOUT-CU...KER-/191600000606?hash=item2c9c3ffe5e&vxp=mtr

 

[Redrig]

Thanks wood , I have been eyeing several of those on eBay but I think I am going to go the route of using 2 access points so I don't have to cut the stringer.

I have found these

http://greatlakesskipper.com/larson-...atch-trim-ring

Those are ideal size for my layout , I emailed great lakes about the thickness of the aluminum and they responded with this .

"The outter flange is 10 gage and the inner flange is 14 gage thick.

I really couldn't say whether they would be suitable to walk on though. They are just aluminum"

All of those standard ski lockers have that ring made of aluminum right?

Do you think 14 gauge is enough to support the traffic area ?

I have access to a wood shop so fabbing up the planks to fill those is no issue .

Thanks again

 

[JASinIL2006]

That looks like what I have on my Larson's ski locker. That ring actually goes on the locker lid. The lid them fits into the hole, and the flange keep the lid from falling through. It's completely strong enough to stand on.

 

[Redrig]

That looks like what I have on my Larson's ski locker. That ring actually goes on the locker lid. The lid them fits into the hole, and the flange keep the lid from falling through. It's completely strong enough to stand on.

Awesome - Thanks JA for the insight , I was wondering why the holes are on the inner flange vs. the outer flange . makes sense now after your description.

I will use them a little differently I will mount them to the deck rather than the lid, that way they are fixed to the deck and then I will just fab up some teak or whatever to make the lid.

Thanks again.

 

[JASinIL2006]

That should work, but I'd make sure the lid fits pretty tightly into the opening if you're going that route. The wider the gap that aluminum has to span, the better the chance you'll be able to get it to buckle when you put weight on it.

 

[Redrig]

That should work, but I'd make sure the lid fits pretty tightly into the opening if you're going that route. The wider the gap that aluminum has to span, the better the chance you'll be able to get it to buckle when you put weight on it.

Yep , exactly. I will make them nice and tight, not only for the support but also so they are not rattling around and falling out while towing or on the water

 

[Redrig]

Quick question fellas , So I have a few new pieces of deck to be adding around the ski locker and bilge area.

1. What do I put on top of the stringers when laying down the deck ?

2. I have routed the edges of the deck where it meets the bilge , what will wrap best around that 90 degree ?

3. lastly , what do I do at the seams of the deck ? my initial plans are to cut the seams at 45's and then fill the "valley" with peanut butter and then glass over the top with 1.5 CSM ,almost like a drywall seam , will that work ?

picture to help explain what I am asking. Thanks

 

[DeepBlue2010]

My comments inline

Quick question fellas , So I have a few new pieces of deck to be adding around the ski locker and bilge area.

1. What do I put on top of the stringers when laying down the deck ?

Your choice. You can use nothing at all if the deck will be screwed in (of course you need to seal the screw) since no significant noise generating vibration will be produced due to the mechanical fasteners. Alternatively, PL, 5200 will provide a good bond between the deck and stringers.

2. I have routed the edges of the deck where it meets the bilge , what will wrap best around that 90 degree ?

I would use 1708. Try to wet it on a piece of wax/parchment paper first and it will turn around that corner much easier.

3. lastly , what do I do at the seams of the deck ? my initial plans are to cut the seams at 45's and then fill the "valley" with peanut butter and then glass over the top with 1.5 CSM ,almost like a drywall seam , will that work ?

Instead of 45, try to match the angels of the hull. Don't use CSM, I would go with 1708

picture to help explain what I am asking. Thanks

 

[Redrig]

My comments inline

Instead of 45, try to match the angels of the hull.

Sorry , I am not following you here.

To explain , I have cut just a portion of my deck off to access what is underneath the deck and add a storage locker, I ran into a stringer that I wasnt expecting to be there and had to change my inital ski locker plans , see earlier in the thread.

but anyways, I now know what is under there and the forward probably 2/3 of the deck is stock and untouched , I just need to mate the " new deck pieces " around the ski locker up and to the existing deck and hopefully make a nice clean transition. Does that make sense ?

and thanks for the response and tips on the other questions.