another stringer question

[trailerbound]

I've been a lurker here for sometime, lots of great info and knowledgeable people. I've done a dozen or so boats over 20 years and have never heard what I've read here.on another thread that was about fiberglass stringers,there was a statement that the shape of the fiberglass covering the stringer was the strength not the actual wood???so if that's true then just reglassing over the rotted stringers would be ok? I've always removed the wood and replaced it.seems that it would be an easier job if so.I'm the recent owner of a 1959 Glasspar seafair sedan and am hoping this is my last restoration.

 

[Woodonglass]

Uhmm I think you may have mis-read that OR if it was stated that's not entirely correct. It's not just the shape but also the thickness of the glass. If the total thickness of the fiberglass is approx. 1/4" and the stringer is 3-4" wide and it's properly tabbed to the hull then yeah the inner core material is probably not all that important and acts primarily as the mold for the glass. If your 59 Glaspar stringers meet all these criteria then I suppose you could grind the glass and then add 2-3 more layers of glass over the existing glass and they would be ok. It's hard to tell without actually seeing what you're working with.

 

[trailerbound]

thanks for the reply. I haven't tore the floor up yet im waiting for this summer before I do.reply #5 in the link is what I was reading,
http://forums.iboats.com/forum/boat...hull-repair/326419-solid-fiberglass-stringers

 

[Woodonglass]

Well, in post #7 he states basically the same thing that I did. It's not just the hollowness but also the thickiness of the laminations and the shape of the stringer. A "Half Pipe" shape being the most common. Most boat MFG go CHEAP and therefore use wood to "BEEF UP" the strength of the stringer and thus use less glass and save money.

 

[jbcurt00]

Why would you want to go to the expense, effort and trouble to redo the deck and transom and want to leave old rotten wood (ie wet and heavy) inside the stringer.

If wet enough to freeze the stringers would be a liability I wouldnt want left in the boat.

A boat w a redone deck and transom but w a covered up rotten stringer wouldnt be a boat I'd want to buy either.

 

[trailerbound]

exactly! I've always removed the rotted wood.i figured the wood was for structural support also.im still going to do like ive done which is replace all the wood and use epoxy/fiberglass. just thought it was odd that its the glass that provided the support...

 

[ondarvr]

It's one of those difficult "it depends" type questions.

Normally one of the reasons the stringers are rotten is because of how poorly the the glass work done the first time, so the glass frequently needs to be replaced and doesn't leave you an option. But in some situations it would work to put additional glass over the old stringers. I'm a fan of hollow stringers.

 

[tpenfield]

My comments . . .

The referenced post is about a solid fiberglass stringer (no core material) instead of wood as the primary material. In practice, using wood as the primary material for a stringer does result in much of the strength coming from the wood. Fiberglass is added to bond the stringer to the hull as well as provide a moisture barrier. Fiberglass on the top portions of a wood stringer can also add strength to the stringer.

As to the idea of glossing over a rotted wood stringer instead of replacing it. . .

Often the wood life's of a boat structure are fastened together before fiberglass is applied. Moisture is free to roam to other pieces of wood that are connected. So removing the wet/rotted wood helps avoid further water migration throughout the remaining structured.

Practical aspects of applying fiberglass over something that is wet at the core may result in a poor outcome as the existing fiberglass will have a high moisture content affecting the bond of old to new fiberglass .

 

[trailerbound]

thank you all for the replies.i will definitely remove the old wood.i will post a build or rebuild thread when I start.any advice is always welcome.

 

[tpenfield]

My comments . . .

.

As to the idea of glossing over a rotted wood stringer instead of replacing it. . .

Often the wood life's of a boat structure are fastened together before fiberglass is applied. Moisture is free to roam to other pieces of wood that are connected. So removing the wet/rotted wood helps avoid further water migration throughout the remaining structured.
.

Pardon the auto-correct of my iPad in the above reply. I meant to type 'Often the wood components of a boat structure are fastened together . . . '

My stupid iPad obviously knows nothing about boats

 

[ondarvr]

I have the exact same issue with my iPad, when I go back and read something I posted earlier it can be embarrassing to see what was actually printed. The short time we have to edit posts makes it even harder.