lost and need help replacing stringers

66mstgfsbk

Petty Officer 3rd Class
Joined
Feb 3, 2009
Messages
97
i think i got the general ideal. the boat is a 84 malibu with a omc stringer. right now im cutting out the rotted ply wood on my transom, then i will replace it with new wood and glass it in with cloth. once that done is the part that i need help with is the stringers that the engine mounts to, they need to be replaced. if i under stand this right i have cut my wood to size, then i will lay down some pl prem down to take up the gap so i get no stress cracks in the hull? once that is in and set i will glass over the wood with cloth or can i use biaxial? once the stringers are in place and glassed in i can set the engine back into the boat. is that corect?

ive searched the forum and dont 100% understand the process. i just dont want to install the stringers wrong. thanks for any help.
 

proshadetree

Lieutenant Commander
Joined
Jul 19, 2008
Messages
1,887
Re: lost and need help replacing stringers

Thats it just make sure its square.Same height as before and sealed up better than factory ever thought of.
 

J. Mark

Petty Officer 1st Class
Joined
Sep 3, 2008
Messages
303
Re: lost and need help replacing stringers

and buy a full case of the PL Premium adhesive. I used 9 of the big tubes to bed my stringers and floor supports and before bedding the fit seemed pretty darn close.

To make a pattern for my stringers I placed a 2x8 directly on top of the stringers and scribed a line from the hull along the bottom of the new wood on each side.

If you could remove the stringers intact they would provide a better pattern, but mine were so shot that I didn't think I'd get them out in one piece. Once I got them out there really wasn't enough good wood to make a decent pattern, so I was glad I did it the way I did.

Some folks suspend a board over the location for the new stringers to make the pattern on the underside.

I chose to use dimensional lumber as that is what I removed. My boat only used plywood in the transom, a bulkhead, and a few braces on the sides of the hull. (Excluding the floors of course) The plywood was all delaminated and more heavily rotted than the dimensional lumber. With proper sealing and preparation I am convinced that we can build better structure than out boats ever came with from the factory.

I chose epoxy because I work outside and don't have a large enough shop to get my boat into. Epoxy seems a bit easier to deal with in cooler weather. It also allowed me to preseal the wood before installation. The downside is it is far more expensive and going to polyester resin after using epoxy is generally not a good idea.

The idea of replacing stringers is more daunting than the task itself, so be comfortable with the idea that you can do it.

Take lots of measurements before hand and put them somewhere safe.
 

92excel

Chief Petty Officer
Joined
Oct 6, 2008
Messages
477
Re: lost and need help replacing stringers

If you use poly you have to use MATT then cloth then Matt then Cloth.. with epoxy no matt is needed..

1708 is great for stringers two wraps both sides, transoms three wraps, and tabbing in your deck to the hull 1 layer.

as for bedding.. i put my stringers in place first.. lifted them off the hull about a 1/4 inch with plastic shims and then forces the PL under them.. any left over PL you can use to reduce the 90 angle where the stringer meets the hull and make it more of a radius.. your glass will lay better...

read oops hull extention.. great tutorial.. index on page one.. my project is below.. and there are a ton of completed projects in the completed projects section.. read all of those before you start and then you will be comfortable..

and if no one said it yet.. WELCOME TO IBOATS!
 

tallcanadian

Captain
Joined
Sep 7, 2006
Messages
3,250
Re: lost and need help replacing stringers

i was lucky enough to get an old stringer out in one piece to use a model. i had 4 2x4 stringers and 1 2x6 stringer for the middle beam. i used kiln dried spruce and wrapped them in glass.
 
Top