A meaningful discussion about replacement of wooden stringers..........

Hi guys;
I have a new to me 1984 Bayliner Capri cuddy 16' sitting here begging for a new floor. I have already thrown away the completely trashed fold-down seats and am planning on a belly tank, dual batteries, perko switch and pedestals for more fishing room. The floor is soft all around the ski locker in the center and is soft back to the transom (outboard BTW), but seems fairly solid everywhere else. I am not thinking I am going to get lucky here, I am planning on an entire floor replacement just to be safe.
I am wondering about what happens when I get to the stringers? Am I going to find rotten wood? Am I going to find I have one of the Bayliners with no wood at all inside of the 'glass stringers?
I have done a lot of research in the forums and have seen a lot of the teardowns, rebuilding and restorals and have paid a lot of attention to stringer and floor replacement. You guys here are just a wealth of knowledge that I truly appreciate.
I have a question that may incite some strong feelings in some of you, and I am prepared for some of the comments I may get (I'm a big boy, I can take it, Doc). Please understand that this is my first boat and I really want to get this right the first time.
After reading up on a lot of wooden stringer replacement and glassing them in and such, I always thought that the wood was there to impart a measure of strength into the hull of the boat. Last night I read in a post that the wood is really only there to be a "form" for the 'glass and not really for strength. There is even a company out there that manufactures stringers out of dense styrofoam.
The question from my "logical" side (read: cheap and lazy) is if the wood is only there as a form for the 'glass, and the 'glass that is there is still good but the wood is bad; couldn't I just lay some new 'glass over the old and be done with it? Or would the rotting wood underneath have an adverse reaction with the 'glass and make it go bad prematurally? Now, I am only asking this question about stringers; not a transom, the answer is quite obvious in that case.
I am not asking this to try to get out of doing it right, but to try to figure out what would really happen if this repair were tackled in this manner? Has anyone seen the result of this type of repair? How did it turn out? Or did it fall apart a few months later and have to be done a second time the correct way?
A lot of you guys here have been around boats for quite a while and I would really love to hear your stories, experiences, trials and tribulations, predictions; whatever you have.
Have at it; I'll be back late tonight to see what kind of storm I have brewed up........................man, wish I could pop a beer for this one, but I'll be at work when I get to check on it............................Let the games begin..........
George

Re: A meaningful discussion about replacement of wooden stringers..........

The age old question of stringer material . . . You gotta love it.

I will be doing stringers and bulkheads on my boat in the next couple of months and inexpensive (cheap) and less labor intensive (lazy) are going to be #2 and #3 on my list.

#1 on the list is going to be strength. Wood does not hold any distinct advantage over other materials or approaches in terms of strength. Boat companies have used it because it is an easily worked material and offers a good trade off of cost, strength and longevity.

In many boats the wood is a major part of the strength and the glass is more for adhesion and protection. As more fiberglass is used in the covering of the wood the glass becomes a more significant part of the strength.

However, some boat manufactures have moved away from wood stringer systems and are going with composites. So, there is some wisdom behind that move, and it may not be cost. So, don't feel that you have to go with wood just because you will get a fair amount of advice for that approach.

I will not be using wood, as I am confident that it can replace things on my boat in a way that will be stronger and last longer than wood.

I do plan on removing rotted wood, because if left there, the rot will continue to spread into other areas of the structure that are currently fine ( and made of wood).

There are some dimensional considerations with an approach of merely glassing over the existing stringers, particularly if the gas tank goes in between the stringers. You want to make sure everything will fit back into the boat when done.

I'm sure we will have some lively discussion on this overall topic . . .

Re: A meaningful discussion about replacement of wooden stringers..........

Ted;
Thank you for the reply. I also agree that the main concern should be strength. This is what I originaly assumed the wood was for. I also agree that bad wood should definitely be removed if it could possible affect other (good) wood. But.......... what if the bad wood would not affect good wood? If a person were to seal bad wood inside of fresh 'glass; would it negativiely affect the structure of the boat in any way? Such as, would there maybe be a chemicle reaction between the rotting wood and the 'glass? Is this even a concern?
Granted we all are proud of our boats, be them ever so humble.....and we all want to ensure that we complete these projects and see the boat as being at least as good, and preferably better than when they were when new. BUT....what if???? I certainly hope more of the board members answer my original post. This could bring up some lively discussion; and discussion is good for the soul.........

Re: A meaningful discussion about replacement of wooden stringers..........

I did find some threads from the past with lively discussion about the use of 'alternate' stringer material, so perhaps the Holy wars have been fought. I'll send you a link or two in a Private Message (PM).

I don't know of any issues regarding isolated rotting wood versus fiberglass (FRP), but that's why we have Google.

My bigger concern is being able to say with certainty that the rotted areas are completely isolated. Given that the wood structures are assembled in place and then glassed over, it would be more the opposite. The sections of wood are in contact with each other and the rot can spread.

I have evidence of this in my boat, where the bulkhead rotted and migrated to the stringers. The only way to check to see if the rotted areas are isolated by fiberglass would be to open the effected sections up and take a look at the joining points. So, having done that, you might as well take the bad stuff out, and isolate the good stuff for further preservation.

Just my thoughts . . .

Re: A meaningful discussion about replacement of wooden stringers..........

I also agree that the main concern should be strength. This is what I originaly assumed the wood was for.

Click to expand...

Ayuh,.... The Wood also gives screws something to bite into...

Re: A meaningful discussion about replacement of wooden stringers..........

I think you'll find this informative...
http://www.westsystem.com/ss/assets/HowTo-Publications/Fiberglass-Boat-Repair-and-Maintenance.pdf

Re: A meaningful discussion about replacement of wooden stringers..........

Woodonglass said:

I think you'll find this informative...
http://www.westsystem.com/ss/assets/HowTo-Publications/Fiberglass-Boat-Repair-and-Maintenance.pdf

Click to expand...

This is a great reference (Thank you Woodonglass !!!) After reading it a bit, about stringers, I have come to realize that my stringers did not rot, the 'core' just became 'inactive' ...

Re: A meaningful discussion about replacement of wooden stringers..........

Yeah, and don't you forget it!!!!! The Stringer Police ARE watching!!!!!!

Re: A meaningful discussion about replacement of wooden stringers..........

projectcop said:

Ted;
Thank you for the reply. I also agree that the main concern should be strength. This is what I originaly assumed the wood was for. I also agree that bad wood should definitely be removed if it could possible affect other (good) wood. But.......... what if the bad wood would not affect good wood? If a person were to seal bad wood inside of fresh 'glass; would it negativiely affect the structure of the boat in any way? Such as, would there maybe be a chemicle reaction between the rotting wood and the 'glass? Is this even a concern?
Granted we all are proud of our boats, be them ever so humble.....and we all want to ensure that we complete these projects and see the boat as being at least as good, and preferably better than when they were when new. BUT....what if???? I certainly hope more of the board members answer my original post. This could bring up some lively discussion; and discussion is good for the soul.........

Click to expand...

Ok.. I will bite at this thread as a Pro perspective.

See the thing is your kinda conglomerating all stringers/builds into your question.. your asking for a simple answer to a complex question.

Most of the boats that are being restored here in Iboats are NOT constructed with mold-in stringer systems.

You cant lump boat systems that require structure for Inboards..Outboards.. or I/B's .. They are totally different builds.

The best bet for members of Iboats is to recommend the same build as you started with.

If you want to MOD a boat .. please explain the boat/build/year/make/model as it will help to determine if it is remotely possible or safe. They are not all the same ..

YD.

Re: A meaningful discussion about replacement of wooden stringers..........

Ahem!!! He DID!!! "I have a new to me 1984 Bayliner Capri cuddy 16'"

YD You REALLY need to READ the entire Thread.

Re: A meaningful discussion about replacement of wooden stringers..........

the above is a good post.

moulded stringers are (generally speaking) enginerred.

the rule of thumb is to replace what was.

dont forget, that a glass encased wood stringer will last 20-50 years with average up keep. this is much longer than the average user wants to keep the boat !

Re: A meaningful discussion about replacement of wooden stringers..........

There was an article on the internet, that was an interview with an engineer from Ranger Boats, about their transisiton from wood stringers and transoms to composites. I've searched and searched and can't find it but will keep searching.

Basically it said that the reason for going to composites had nothing to do with cost or longevity (the cost is actually much higher) , but more just public demand. He stated that wood is still today the best materail for boat building (stringers, transoms, etc), becuase it's cheaper, holds fasteners much better and is easier for form. Properly maintained (and he said this is a key to most anything) the wood will last for 30+ years, which is way past the life expectiancy of any boat, although there are many out there past this age, it's still the designed life span.

Now, I guess your questions was more like do I need the wood, and my opinion is yes. I don't feel like in the older boats the fiberglass itself was designed for 100% support without the wood. If that was the case cardboard, foam, just plain molded stringers would have been a cheaper material to have used as just a "form". It is true that there are manufacturers making foam cored stingers as replacements, I personally have not ever used them, as I tend to stay with what was there orignally.

I agree with YD that not all boats are the same, nor are they designed the same way. I strongly feel the wood plays a part in the struture of the craft and should remain there during a restore. Boats designed with foam core stingers are designed from the mold up to be that way. I am not an engineer so for me anyway, I'll stick with what an actual engineer went with....most of these restores on the forum are 20+ years old which means the design was prettry darn good. I say keep it the way it was...

My .02 CW

Re: A meaningful discussion about replacement of wooden stringers..........

Wow;
Great discussion going here. @Bond-o, AHHA!!!! I don't know why, but I did not even think of the deck screws having something substantial to bite into. Great point; thank you!!
All of you are making good points. Thank you all very much. I pretty much know the way I am going to go on my 'liner. If I find a bad stringer, I am going to replace them all. Why do it halfway??
I asked the original question wanting to get some discussion going here, and maybe getting an expert to chime in saying; "no, you cannot do that, and "thisXXXXXX" is why..........

Re: A meaningful discussion about replacement of wooden stringers..........

Someone hit the nail on the head. It is all about upkeep and care. There have been all wooded boats for almost 100 years, and some one them are still around because they were taken care of.

Re: A meaningful discussion about replacement of wooden stringers..........

Maintenance and upkeep are indeed the key. I have tools that belonged to my father and grandfather. I am in my 60s. I used these tools professionally and they are still good. They do not have the improvements of modern tools but are still usable. My son has workers that will go through tools in a workday or week. The boat I am rebuilding would not have needed it if the PO would not have let water build up and stand for an extended period of time.
I do have a question concerning fasteners and flooring. You talk about screwing the floor to the stringers/bulkheads. If you use 5200 would that not work as well. 5200 is an adhesive that bonds to the strength of the materials it is attaching? If this is so, what is the need for screws? Screws is another penetration of the system that is trying to be sealed. I know that the screws will be glassed over, but still seems like it would not be needed.