new stringer system help please !!!

floflodr

Seaman Apprentice
Joined
Jan 2, 2008
Messages
42
hi everyone, im going to put in new stringers in the next few days, but i have thought about changing the way they are going to be installed.

the reasons are, with the old system and 1 main wood in the middle the water cannot flow properly to the end of the boat.
im looking to make my boat as solid as possible, so i have thought that the new setup may be more efficent

thanks for any help in advance
please see a pic of the hull with a drawing i made.
 

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oops!

Supreme Mariner
Joined
Oct 18, 2007
Messages
12,932
Re: new stringer system

Re: new stringer system

i am not a naval archetect.....

so i can only guess....:D

but the keel takes a tremendous pounding in larger waters or chop at speeds.....so it needs a stringer......

hence...pic #2...out

in cornering at higher speeds the hull will encounter twisting force as the screw trys to push the boat one way, the chine trys to dig in and the other will flex....so pic #1 is out......

i would build according to the orgional design.....3 strings...

seal them with resin and glass so the water won't get in them.
then add a drainage channel to the bilge. make sure tha the water can flow unrestricted to the bilge....even if you have to notch the bulkhead....just make sure the notch is sealed....

dont mean to shoot down creative thinking....(ever)... but boats encounter crazy stress.

cheers
oops
 

fixb52s

Chief Petty Officer
Joined
May 14, 2004
Messages
463
Re: new stringer system

Re: new stringer system

if #1 was the way the factory did it, I would do it the same. It appears the rear bulkhead had 2 drain holes so the water would go down to the bilge and drain, but that center would be wet. I would rebuild it as factory, seal it all up with epoxy and call it a day. I would extend the center beam up to the bow though.​
 

floflodr

Seaman Apprentice
Joined
Jan 2, 2008
Messages
42
Re: new stringer system

Re: new stringer system

yes. number one is the way it was made by the factory, but im uncertain if that may be the best way to go.

im still uncertain about what to do, as now i got one for the old design and one for the new one.
Could i get some more comments from you guys please, i would appreciate it a lot
 

NoKlu

Senior Chief Petty Officer
Joined
Feb 23, 2008
Messages
786
Re: new stringer system

Re: new stringer system

I'm no boat expert but it would seem that the keel is the spine. If you take the stringer and move it, No spine.
 

oops!

Supreme Mariner
Joined
Oct 18, 2007
Messages
12,932
Re: new stringer system

Re: new stringer system

see in number 1 where the engine box is?....

run those strings straight foward.....so you have three

btw...that is an unuasual stringer design.....what legnth of boat is that?
 

tmcalavy

Rear Admiral
Joined
Aug 29, 2001
Messages
4,005
Re: new stringer system

Re: new stringer system

Add a spine stringer to your "new" drawing and you've got a better system than the "old." Notch the stringers at the bottom so water can drain back to the bilge, make sure all are encapsulated with resin.
 

floflodr

Seaman Apprentice
Joined
Jan 2, 2008
Messages
42
Re: new stringer system

Re: new stringer system

so you guys are telling me that the old system is not actually the most ideal way to go, if i understood right my new system was missing the spine in the middle, which i have added to the new drawing attached, please give me your opinions and if i should rather make it that way.

this is a 16.5 center console, with a 90HP johnson 1990 the ID is CCC, this used to be the ID for chris craft corporation, but has later changed to chris costums corporation, can anyone tell me what brand of these two my boat may be ?

the box at stern is for the bilge pump
 

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Robj

Lieutenant
Joined
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Messages
1,441
Re: new stringer system

Re: new stringer system

I would just do it the same way as it originally was. That is the way it was designed. Why make more work for your self by putting in all those other stringers, when based on the original design they are deemed unnecessary? Just make some effort to allow the water to drain properly.

Have a great day,

Rob.
 

oops!

Supreme Mariner
Joined
Oct 18, 2007
Messages
12,932
Re: new stringer system

Re: new stringer system

a 16.5 is only 12 or thirteen on the water line......

rob j is correct, as the orgional manufacturer thought it wouldnt need the extra support.........

if you build it the way we suggested (with three strings)...it will be stronger...and built in a standard way....however it will add some weight....approx 40 lbs.....

it is your boat....you can build it any way you want......both ways will work....

but when building....just make sure you adress the problem that caused the damage in the first place

cheers
oops
 

Coors

Captain
Joined
Dec 8, 2006
Messages
3,367
Re: new stringer system

Re: new stringer system

Dunno, but my 20' 10" Four Winns has no keel stringers, and will take a beating.
 

oops!

Supreme Mariner
Joined
Oct 18, 2007
Messages
12,932
Re: new stringer system

Re: new stringer system

what?????

no keel string????

what year coors?

have you been in there?

did they do somthing different do you think?

is the layup different...i know i saw a new chris craft that i would trust with out a keel string....but thats it
 

Coors

Captain
Joined
Dec 8, 2006
Messages
3,367
Re: new stringer system

Re: new stringer system

In cuddy, a 1 by 4;Maybe 6' long. The rest= middle fuel tank centered - none, none under engine. It had 2" by 6", 1 by 6's raw fir, covered by shaved foam, to install the f/g on-3/8 " thick, on sides and top, mat, then (couldn't tell, could have been roven, or; - it was so soaked, all fibers were one with the resin).

The 2 main stringers are on the outside of the engine mounts, probably 2' off the keel, to the sides.

I've had it in 4' waves, 8' timing, had to just bull through, with the deep vee, having a lot of the deck down, just temp, looked later, and all the stringers are good.

The f/g seems to be the strength, filled now with epoxy/biax/milled/wood flour/sawdust, it may be heavier, but I don't think anymore problems are there.

As an aside; Four Winn owners, your transom is sealed from the stringers- they won't rot each other.
 
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Robj

Lieutenant
Joined
Mar 22, 2007
Messages
1,441
Re: new stringer system

Re: new stringer system

My boat does not have a keel stringer either. It is an 18 foot. It all depends on how it is designed. I am sure the hull was designed in such a manner that it does not need a keel stringer. You just need to beef up the glass in the keel area, and have a few bulkheads.

Have a great day,

Rob.
 

floflodr

Seaman Apprentice
Joined
Jan 2, 2008
Messages
42
Re: new stringer system

Re: new stringer system

would it be an option to make the stringers out of plywood ?
 

Robj

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Messages
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Re: new stringer system

Re: new stringer system

would it be an option to make the stringers out of plywood ?

You bet, that is what I would make them from. Exterior grade douglas fir, can use DRY pressure treated if you like. Do a search on the topic there are alot of posts. Don't want to hijack your thread and turn this into a pt or not pt debate. You can laminate ply together with matt and resin to get the desired thickness. Hope this answers your question, any more just ask.

Have a great day,

Rob.
 

floflodr

Seaman Apprentice
Joined
Jan 2, 2008
Messages
42
Re: new stringer system

Re: new stringer system

thanks for everyones help so far, im only relying on you guys !!!

i started to cut the stringers today, im making them out of plywood, glued and screwed together.

now, i have one question about my old stringer system, as i noticed there is a gap between the stringer and the hull walls, as you can clearly see on the pictures. Wouldn't it make sense for the stringer to be in contact with the walls, to add more strength to the hull ?

i will use the old system, but i will install one additional stringer in the bow.
 

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floflodr

Seaman Apprentice
Joined
Jan 2, 2008
Messages
42
Re: new stringer system

Re: new stringer system

please help guys, i want to get this done ASAP

please let me know if i should make the new stringers some larger then the old ones, so they will be touching the walls of the hull.
As you can see on the pictures, the old ones are not making contact on the sides.

thanks a lot for any help
 

Lou C

Supreme Mariner
Joined
Nov 10, 2002
Messages
11,798
Re: new stringer system

Re: new stringer system

In cuddy, a 1 by 4;Maybe 6' long. The rest= middle fuel tank centered - none, none under engine. It had 2" by 6", 1 by 6's raw fir, covered by shaved foam, to install the f/g on-3/8 " thick, on sides and top, mat, then (couldn't tell, could have been roven, or; - it was so soaked, all fibers were one with the resin).

The 2 main stringers are on the outside of the engine mounts, probably 2' off the keel, to the sides.

I've had it in 4' waves, 8' timing, had to just bull through, with the deep vee, having a lot of the deck down, just temp, looked later, and all the stringers are good.

The f/g seems to be the strength, filled now with epoxy/biax/milled/wood flour/sawdust, it may be heavier, but I don't think anymore problems are there.

As an aside; Four Winn owners, your transom is sealed from the stringers- they won't rot each other.

Coors, I have probably the same hull as yours, but it's a 200 Horizon, you have a 205 Sundowner cuddy, right? Anyway in the original literature (fast facts on the FW website) for the boat, it mentions something about '5 stringer reinforcement' and when I re-did mine I saw the 4 main stringers that run from the bow to the rear bulkhead where the outer ones continue back and the inner ones stop at the bulkhead and then the engine stringers go from there to the transom. I figured that this 5th stringer must be under the gas tank area and the ski locker in the bilge areas, but since the structure there was not rotted I didn't open up either of those areas. Who knows maybe there is a stringer of some kind in there. It says the same thing for both your cuddy and my Horizon bowrider.

I have found that this is a great riding hull for its size, the 21* deadrise must help, it takes waves and wakes much better than I've thought based on its size.
 

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Coors

Captain
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Re: new stringer system help please !!!

I had to open up the cuddy, there is a 1x4 in the keel with maybe 1/2" of chopped on it, but it seems to stop at the gas tank front bulkhead.
 
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