Bedding stringers?

Purpose of stringers?

Hi folks,
I am curious. What is the purpose of the stringers. Is it soley to support the floor?
Do they work off the transom to keep it from folding onto the floor under acceleration?
Do they have to be solid along the hull or can a person make cut outs Like a foot of contact and a foot of hole off and on for the length of the stringer to save weight? Like ^-----^------^------^------.
Thanks
Mike

 

There are two distinct parts that work together to keep the shape of a boat or anything else. They are ribs on station lines and stringers on buttock / water lines.
Think of what would happen to a wood house that was built without 2 x 4s. Even wood sailing ships depend on ribs, spars and stringers. It is even more important to a fiberglas hull. I did a small boat onetime and wanted to see how it floated before the guts were installed. It sat in the water ok but nobody could get in it or it would have folded in two. Don't try to reinvent the wheel, just learn how it's done.

 

Why don't you tell everyone here what you're trying to do. There's a lot of years of knowledge in this site that might help. Are you repairing a boat? Building one?

 

Thanks

Hi Russ and Eyes!
Thanks for the replies.
I am rebuiling and old Glasspar G-3. It has been done before so I dont know how it was done when new in 1961.
It is going pretty good. I have quite a bit of autobody experience but no boat builing experience.
The transom came out great . The curved transom had me worried but I am happy.
The stringers were one main board down the center of the hull with two smaller ones on each side for the length of the boat. They were jammed down solid to the hull in resin. I know that the G-3's came with 1/4 floors when new and I doubt that the way it is is adequate.
Every last piece of wood has been removed. I have the transom and sponsons finished so far.
This thing has been a hoot so far. It came with the original motor (75hp Johnson) and trailer but everything needs redone. It is, however,all there. Every piece of trim etc. is there.
If anyone has any ideas on how I should fabricate the stringers I'd appreciate the help.
I doubt that I go back with them like they were.
Thanks a million
Mike

 

Is it a Ski boat or Sedan?

Besides that, both are made with wood stringers, one in the center and a grid to reinforce when the floor gets in place.
Here is a pic of both boats and one being restored. I will try to get you a better pic of the restoration process of that boat and post some explanation with it.

 

Howdy Eyes!

Hi Eyes,
Nice looking G-3! I just put mine up for the day. I have the transom replaced and finished up the sponsons today. I put white oak back in them. They call it post oak around here. Itwas dry as can be and is not supposed to rot. It is HARD.
There were no boards running crossways in my boat.
Just the five stringers running front to back.
I did not think it was right.
I'm trying to watch the weight. That old Johnson is a monster. I have not weighed it but it has to be heavy.
What year is your G-3? How do you like it?
Well,I better get going. I just cleaned up and I'm beat.
It's real hot here today and I've had just enough beer that a nap is going to be easy to come by.
Thanks for the pictures
Mike

 

Hi Mike.
The pics of the G3s are not mine. I've just posted them as info for others, so they can see what you're talking about and give you some advise.
Here are a couple of links of G3s site that might be interesting for you:
http://www.fiberglassics.com/g3/glasspar-pages/G3_225.html
http://boston.craigslist.org/boa/164368681.html
http://g3.clickusfirst.com/
One thing, always seal your wood before fiberglassing. You can use CPES (Clear penetrating Epoxy Sealer) or thinned Epoxy resin. Soak the wood real good and let cure before installing.

 

Hi Eyes

Hi Eyes,
Thanks for the links. The first two I'm familiar with. I bought my boat from an ad on Craigslist. It was from a guy in LA. but the boat was in WI. Only in the electronic age could a guy from MO get a boat from a guy in LA that is stored in WI.
I'm soaking the wood in resin and encasing what I can in cloth too but I dont know that encasing the stringers is a good idea. The wood in the sponsons and transom are subject to seapage. I did put a drin in on each side so if the sponsons should ever seep the water will run out into the hull.
They used to channel the water to the unfinished ends of the transom.
I think I have it sealed up pretty well.
Thanks again for the links.
Mike

 

My Glastron stringers

I have read on other threads here that the wood inside the glass of the stringers were just a form and the glass did all the work of supporting weight and stress. My question is my project has some rot where the did a poor job of glassing the crosspieces where the joined the stringers. If the wood is unimportant can i leave the rotting wood(its still holding it's shape) and just re-glass the hell out of the stringers and joints? Also i've read that you shouldn't mix epoxy and regular resin so can i soak my boards in thinned regular resin then install them? I'll post pics of my monster later its a '75 glastron v-178.

 

Hi JJ, Yes, in a way the wood is just a form but since it is there and offers some strength I would first soak the wood, even the rotten wood, in CEPS (clear Epoxy penetrating sealer). That will somewhat fill the pours in the wood and restore some of it's strength. Polyester is not a good choice for that. We made transoms of polyester and wood chips many years ago but they do not hold up well. Polyester is simply not that great when it stays wet constantly. OK! before everybody trys to crucify me for saying that I will add, That is why the better boats are now made with Vinyl Ester as an outer surface. There are technical reasons why but quite complicated chemically.
Oh yes the rule is Epoxy sticks well to Polyester but Polyester does not stick all that great to Epoxy. Be sure to have a greasless VERY well ground 16 or 14 grit surface to stick to then you will have some mechanical locking as well as chemical bond, and hope the polyester is not a "low profile" system.
good luck,,,,,Russ

 

OOPS,,,,typo,, 16 or 24 grit

 

JJ
I will stick with epoxy. Neve mix different types of resin.
The wood you use must be new and untreated. You can use Pine, Fir, or BC-Exterior grade Plywood all work equally well as material for making new stringers for your boat, but if you can, buy marine grade plywood. Make certain that all the wood is dry, sealed and completely encapsulated with at least two layers of resin saturated fiberglass mat before installing it in the boat. I also suggest that you remove all rotted wood and fill the cavities with some epoxy putty, before sealing with CPES. Like Russ said this will add more strenght to the stringer.

 

Stringer Strength

The reason i figured i could just glass the damaged areas is that the stringers are way strong. I can stand on one and it will support me with no buckling or cracking (btw i weigh 350#!!!!). Also does anyone know where to find glastron diagrams and schematics? i have found the classic glastron owners assoc. and they can't seem too help. Tommorrow i will post pictures of the damaged areas.

 

Also i can only assume the glass is polyester?!? It is original from '75 apparently the boat was bought new in '75 then got a hole approximately 1/2 inch in size and then sat up without repair for the las 20 years. Speaking of the hole would bondo be good too fill the hole before glassing the inside and outside? Also what do i put on the outside glass gelcoat? regular paint? looks are completly unimportant for now.