Advice on stringers and glass

[GregAdams]

The strength in stringers in a small boat is the fiberglass wrapped around them. Not the wood.

If composite stringers are the goal, why use wood inside the stringers?

[GregAdams]

cedar like teak has too much oil it ensure good bonding. the wood material of choice is mahogany. if you look it up it has the best strength to weigh ratio. +/-

Have you had failures with Western Red Cedar? I started using it in the late 80's in lightweight raceboats and haven't experienced any bonding failures yet. I only share this info because this is what worked for me. Many times. I'm not letting out any secrets, because I don't use wood in stringers now.
Mahogany is a fine timber. Have you had success with Mahogany in performance boats?

[Smoking Joe]

With the bonding of any timber it should be wiped down first with thinners. We only use Epoxy glues when using wood, we do a number of Teak floors etc and Teak is a very oily timber. If wiped down first with Epoxy Thinners and glued with Epoxy, you will never have a problem.

[GregAdams]

Hey Joe. Are you watching the World Cup Final?
You must be the only Kiwi left in NZ this afternoon! The rest are at the MCG.

[Smoking Joe]

Hey Joe. Are you watching the World Cup Final?
You must be the only Kiwi left in NZ this afternoon! The rest are at the MCG.

Yeah mate, got the box on, you guys must be feeling pretty confident, McCallum out for a duck, handed it to you eh. Still never say die. Go the KIWI's.

[GregAdams]

Yeah mate, got the box on, you guys must be feeling pretty confident, McCallum out for a duck, handed it to you eh. Still never say die. Go the KIWI's.

Nah... I'm not counting the chickens before they hatch..... still 50 overs to go

[dwilfong]

I'm no old hand at this but I will share what I used.
When building my stringers I used 1/2" Coosa #15 as it is much less expensive than the 1" or 3/4" #26.
I made my stringers in two pieces then used epoxy and DB1700 in between them. Lay them on the floor and put blocks on top to compress as thy cured.
For the transom I bit the bullet and got the 1 1/2" #26 Coosa. You can get a small cut piece at Boat Outfitters in Orland FL. and thy will ship it.

[hsbob]

yes dont use polyester resin, it will not bond to old cured fiberglass. the alum is to transfer the motor thrust load to the whole boat. if you do a search the a picture posting of the brackets id did on my son boat. that was done around 2003. the boat still in great shape.

there are a lot of great suggestion on this board, but you need to pick the right on for your boat. i was interest in a good ski boat where the skier and motor really lot the transom.

i agree the glass over the wood carries most of the load. i have used things like plastic tubes to form ribs and remove the tubes.

[doubleeagle]

yes dont use polyester resin, it will not bond to old cured fiberglass. the alum is to transfer the motor thrust load to the whole boat. if you do a search the a picture posting of the brackets id did on my son boat. that was done around 2003. the boat still in great shape.

there are a lot of great suggestion on this board, but you need to pick the right on for your boat. i was interest in a good ski boat where the skier and motor really lot the transom.

i agree the glass over the wood carries most of the load. i have used things like plastic tubes to form ribs and remove the tubes.

Just wondering what you mean that poylester resin will not bond to old cured fiberglass. Did you bump your head we been using it for over 50 years. Just a heads up the alum will only transfer the load to the edge of the plane it is laminated into. Your post is very confusing and does't offer any real information. Sorry but just saying.

[frederick55]

yes dont use polyester resin, it will not bond to old cured fiberglass. the alum is to transfer the motor thrust load to the whole boat. if you do a search the a picture posting of the brackets id did on my son boat. that was done around 2003. the boat still in great shape.

there are a lot of great suggestion on this board, but you need to pick the right on for your boat. i was interest in a good ski boat where the skier and motor really lot the transom.

i agree the glass over the wood carries most of the load. i have used things like plastic tubes to form ribs and remove the tubes.

WHICH RESIN ??
EPOXY vs. POLYESTER vs. VINYLESTER

Beware of the "one size fits all" approach.

More than 95% of all boats, truck & car bodies made of fiberglass are made primarily of E-glass,
orthothalic polyester resin and isothalic polyester gelcoat. Items constructed with these materials
should be repaired with the same or compatible material. LBI's 301 Orthothalic Polyester Resin is a
good choice for most repairs. It provides a chemical bond to the existing laminate with similar
strength & flexural characteristics.