Stringer Replacement (beef them up?)

[all yeah boy]

I am restoring a 1975 Arrowglass Cheetah, I/O 165hp merc.

The stringers are out and I am ready to purchase,cut and seal new ones. I am wondering should I stick with the style of wood I pulled out (3/4 inch board) or try to put a different style of wood in? I mean replace the board with plywood? And should I use 1 inch to give it even more support? As for the width of the wood, I maybe confined by the groves in the hull which the stringers sit on they are designed for 3/4. The extra 1/4 would not sit on the hull and would overhang as the hull is stepped in this section.

Any advice which is better plywood or board wood for stringers, and should i try to get that extra 1/4 for added strength?

Once again thank you in advance..............

 

[Bondo]

Re: Stringer Replacement (beef them up?)

Ayuh,... I'd use 3/4" plywood, CDX... Sealed in glass, 'n drained, they'll last a lifetime...

 

[all yeah boy]

Re: Stringer Replacement (beef them up?)

Is there an advantage to using plywood vs a single board?

 

[wambs8]

Re: Stringer Replacement (beef them up?)

You can use either plywood or board. If you go with plywood make sure you keep applying epoxy to the edges until they wont suck up anymore. If you use board, Douglas fir is supposed to be strong. Compromise use board for the stringers that run the length of the boat and plywood for the in between stringers. If you don't seal the edges of plywood well, they will soak up water like a sponge. Just replace the size and material that you take out.

 

[Woodonglass]

Re: Stringer Replacement (beef them up?)

Welcome to iBoats!
There is absolutely NO reason to deviate from using 3/4" Exterior grade plywood coated with resin and encased in fiberglass. This IS the accepted method for repairing your boat and it WILL make it as Strong or Stronger than it was when it was New. If you want to upgrade from this you could look into using MDO or HDO plywood. Little Higher grade Material with better PLYS of wood. Use PL adhesive to adhere them to the hull. Give them 72 hours to dry (The PL Adhesive must be cured or it will not let the resin adhere to it). Make sure to round the top edges because glass does NOT conform well to square corners. Fillet the inside corners on the hull with Peanut Butter (Thickened Resin) and I would recommend laying two layers of 1708 Biax and Poly Resin to encase your stringers. www.USComposites.com is a Great resource for your materials. Have you checked your Transom? If you are having to replace your stringers your transom may need to be checked as well.

Pics always help us to help you.

I'm just sayin...

 

[all yeah boy]

Re: Stringer Replacement (beef them up?)

Ah the transom, boy I don't want to go there. I know it may need it, although I have to say that the transom has a lot glass on it and seems to be in better shape. But I have not checked throughly.

I am not afraid to replace the transom (done before for an outboard), more afraid of pulling the motor. How do I get that thing out, lifting wise, not dismantling. Any ideas??