Center (keel) stringer - PVC vs Wood/Coosa

[captsuperfly]

Noticed on a lot of builds, many folks who remove the center stringer (think it's made of fir) replace it with a half pipe of PVC, others might use wood again or foam like coosa.

Curious if anybody has feedback on these decisions after the fact? How has the PVC held up? (I think contender does the same thing).

Also found an old thread that involved a discussion with Mr. Potter on the reason for the stringer (it was support for roller trailers). But that thread seemed to mention that Seacraft switched to PVC at the factory?

any thoughts appreciated.

thanks!

[Capt Chuck]

Originally Posted by captsuperfly

Also found an old thread that involved a discussion with Mr. Potter on the reason for the stringer (it was support for roller trailers). But that thread seemed to mention that Seacraft switched to PVC at the factory?

any thoughts appreciated.

thanks!

That's correct. My '78 had PVC from the factory.

[strick]

Take the wood out...we have seen several boats crack at the center of the keel in the same spot...this happened to a boat I sold a while back... certainly no crack when I sold it...I live in Calif where it's relatively warm most of the time...the keel is made from fir as you stated and is a sponge for water...the theory on the cracking is that in colder climates where it freezes the glass expands and then shrinks...that along with beating the s#*t out of your boat will get you a leak...

strick

[captsuperfly]

Originally Posted by strick

Take the wood out...we have seen several boats crack at the center of the keel in the same spot...this happened to a boat I sold a while back... certainly no crack when I sold it...I live in Calif where it's relatively warm most of the time...the keel is made from fir as you stated and is a sponge for water...the theory on the cracking is that in colder climates where it freezes the glass expands and then shrinks...that along with beating the s#*t out of your boat will get you a leak...

strick

The freezing and expanding is exactly what I'm worried about. It's def coming out. Question is just what to replace it with I'm leaning toward the PVC - though I see you went with foam.

Another thing I noticed is that the hull toward the front really loves to hold water, even with the trailer tilted at a pretty aggressive angle. I saw one build where a guy put an extra bilge pump up there. I'm pushing my fuel tanks way forward, basically against the front step up, so the extra pump isn't really practical.

[SeaChuck]

I have a 1972 23' at the stage of rebuild with the stringer tops cut out and the foam removed. I cut out the top of the keel as well and left the side walls for forms. I plan on using Arjay ceramic pour to replace the wood and glass over.

Any thoughts ?

[AlabamaRick]

Good question Captsuperfly,this is something I have wondered about myself. I am curious about how some of the experienced guys (such as Strick) are doing this once the keel is removed.

[strick]

I think anything is going to be better then the fir that was originally installed...the pic I showed is corecell...kinda expensive for a keel support but it is very dense and wont absorb water...it's interesting how the these topics resurface from time to time...I remember reading years ago on this site where someone stated that the keel stringer was non structural and did not need to replaced....so I left it alone in my 20 sf re build that I removed the deck on....would have been just a few hours more work to replace it

strick

[captsuperfly]

it'll be easier to remove it entirely than crack the potter putty off it!

[CooperDog]

I think the pvc is basically just a form for glass. I glassed over mine with 4 layers of 1708 overlapped like 8, 10, 12 , , 14 thereabouts . With a nice thick fillet. Very strong. Also, acts like a drain tube of sorts. I ran a hose from my anchor locker drain into the tube and filled the cavity under the fish box with 2 lb pour foam.

[captsuperfly]

So this is my weekend project. longest length of PVC I can find is 14 feet, which is short. I'm guessing, since it's just a form, it's not critical that the PVC itself be one piece?