Selecting wood type for stringer repair

[skunkedskippy]

I'm replacing a section of rotten stringer on my 1977 Skipjack. I've heard that the original stringers were fir or spruce. Would it be a bad idea to use a hard wood like oak for this repair?

 

[Scott Danforth]

ACX plywood is what i would use

 

[skunkedskippy]

ACX plywood is what i would use

Thanks for the quick response. The originals appear to be 2x8s. Replacing with the same lumber seems like less headache to me. But I will take this into consideration and do more research before I decide.

 

[Woodonglass]

One thing you should consider is the MFG don't necessarily use the BEST material for the job. Usually the Cheapest and easiest. Plywood is Much stronger in this application and a better choice. Two Pieces of 3/4" plywood laminated together is more than twice as strong and 1 1/2" dimensional lumber. If you Must use the 2x lumber I'd use Douglas Fir or White Oak. But... I'd Highly recommend using the plywood suggested.

 

[Baylinerchuck]

+3 on the exterior grade plywood. Not pressure treated. I used BCX on my project.

 

[skunkedskippy]

Wow... I've been reading these forums for about 6 months before I finally decided to register. I gotta say it's a bit humbling to have multiple iboats "legends" respond to my post.

WOG, with your example, is it ok to "splice" 1 1/2" of plywood to the existing 2" stringer? Would I just make a fillet at the joint before I glass it?

 

[Scott Danforth]

you would have to sister it for a bit. however I would pull out the remaining stringer

 

[pro-crastinator]

pics would be great.

 

[skunkedskippy]

pics would be great.

I'll work on it this weekend.

 

[skunkedskippy]

Photo test

 

[skunkedskippy]

Test 2

That's better.

The gas/water soaked foam under my fuel tank.

 

[Slager]

I'll follow along. The gas soaked foam is nasty stuff.

 

[skunkedskippy]

+3 on the exterior grade plywood. Not pressure treated. I used BCX on my project.

What's wrong with using pressure treated wood?

 

[ondarvr]

PT can be used, but it needs to be dried out, and when it dries it really likes to warp, plus it's normally a poor grade of ply. There is KD PT designed for boats, and it's what's used in new boats that still use wood, but it can be a little harder to find.

 

[skunkedskippy]

PT can be used, but it needs to be dried out, and when it dries it really likes to warp, plus it's normally a poor grade of ply. There is KD PT designed for boats, and it's what's used in new boats that still use wood, but it can be a little harder to find.

Good to know. I'm finishing up my restoration of the deck hatch covers, with PT haha.

 

[Baylinerchuck]

Unless PT is perfectly dry resin won't stick to it. As it dries it will shrink and warp. Chemicals used in it can corrode aluminum. Properly encapsulated exterior grade plywood will last a very long time.

 

[skunkedskippy]

Unless PT is perfectly dry resin won't stick to it. As it dries it will shrink and warp. Chemicals used in it can corrode aluminum. Properly encapsulated exterior grade plywood will last a very long time.

It must've been dry because it soaked up a good amount during the wet out and seems to be sticking very well.

Thanks for the detailed info.

 

[skunkedskippy]

Ok here are a few pics of what I have going on. Not the best photographer so bear with me.

Starboard stringer looking forward. Cut part of the top off near what I thought was the epicenter, hoping I could dig it out and use seacast or similar product. I don't know how far forward the rot goes but it's at least delaminated as far as I can reach my arm. I'll have to cut out more of the deck to assess the damage better.


Looking under the deck along the right side of stringer. Looks like the deck is just sitting on top of the stringer and bulkhead with a shim in between.


Looking under the deck along the left side of stringer. The bulkhead in the background is inside the cabin. Again I'd like to replace just the rotten section because I'd like to go the least invasive route.


Thanks again for all your help.