Fixing wood stringer for the motor mount

[GSX455]

I got a 82 Renken w/ a Mercruiser 120 and I thought the motor was bad, but it turns out the outboard was seized Once I took the out drive off the motor would run. Fast forward as I'm pulling the motor out and the front motor mount, that bolts to the floor are dry rotted.

I've noticed folks here are really helpful, so I appreciate any advice.

The first picture is the fiberglass area showing where the motor mount goes, the second photo shows under the fiberglass it is hollow, so I would need to replace the wood. I'm guessing there is no easy fix, like injecting foam. If I take up the floor, I might as well do the other stringers under the floor, even though the floor feels pretty stable.
Can I just cut below the mount area and add wood, or does the whole floor need to come up?

Hope y'all had a good Thanksgiving, and thanks.

 

[Scott Danforth]

I got a 82 Renken ...... as I'm pulling the motor out and the front motor mount, that bolts to the floor are dry rotted.

dry rot is a misnomer. it was rot....that sat a really long time and had a chance to dry out.

The first picture is the fiberglass area showing where the motor mount goes, the second photo shows under the fiberglass it is hollow, so I would need to replace the wood. I'm guessing there is no easy fix, like injecting foam.

No, there is no easy fix.

I got a 82 Renken ....... so I would need to replace the wood. I'm guessing there is no easy fix, like injecting foam. If I take up the floor, I might as well do the other stringers under the floor, even though the floor feels pretty stable.
Can I just cut below the mount area and add wood, or does the whole floor need to come up?

well, first you need to start by understanding a full restoration, especially on a 37 year old boat. start by reading link 14 in its entirety https://forums.iboats.com/forum/boa...r/295740-how-to-s-and-other-great-information

you will need to at a minimum do a bunch of test drills. use a 1/4" drill, and drill about 3/4" into the stringers, transom, etc. if the shavings come out like fresh wood, then no rot. if the shavings come out wet, or dark, or there is no wood any more because it long ago rotted........ your going to have to pull the floor, and you most likely need to replace all the stringers as well as the transom, then replace the floor. unfortunately there are no safe short-cuts

 

[Woodonglass]

Yeah if the motor mounts are bad, chances are that with a 35 year old boat...You've got a LOT of work to do. I'd HIGHLY recommend a through examination of the Transom, and Stringers. Drilling Core samples is the ONLY way to know for sure.

 

[mickyryan]

just decap and gut it , i will put money that its shot, the guys above me are trying to be nice but they already know as well as i do that its most likely past the point of no return , also need to pull tank test it and new fuel hoses so start reading up and get ready to itch a bit!

 

[Broaters]

That is exactly how our project started out... 2 years ago ;-)

it turned out that there was far more rot and defect than anticipated especially that we had no boating experience so probably a poor initial judgement

We also looked for easy fix but ended up removing nearly all the boat structure, only the cuddy was salvagable.

 

[GSX455]

Thanks for the advice, I'm pulling up the chairs today
I saw the one thread about the 95 SeaRay with the rotten floor and stringers, it turned out nice. Do I starting pulling the floor and cutting with a cutting wheel? Have any of you done the WEST (wood epoxy saturation technique) with any success? I have 2 spare gallons of epoxy to impregnate the new wood so rot does not happen again. Then seal with urethane.

 

[Scott Danforth]

You either go complete epoxy or complete urethane. Epoxy sticks to everything, but urethane wont stick to epoxy.

 

[mickyryan]

poly dries faster not as much of a health hazard to some, but is about 20 % weaker then epoxy as far as binding to stuff, i prefer poly because that's what the boat is made of and i like to know im sticking like products for the application we are using it for poly is fine , however folks are just as die hard about epoxy , its a battle that there is never enough popcorn for once the thread gets started
ps. i also use 2 part urethane based paints because they stick very well to original glasswork/gelcoat

 

[zool]

poly dries faster not as much of a health hazard to some, but is about 20 % weaker then epoxy as far as binding to stuff, i prefer poly because that's what the boat is made of and i like to know im sticking like products for the application we are using it for poly is fine , however folks are just as die hard about epoxy , its a battle that there is never enough popcorn for once the thread gets started
ps. i also use 2 part urethane based paints because they stick very well to original glasswork/gelcoat

Theres plenty of popcorn Micky!...the Poly guys have masks on!

Whatever method you chose GSX, dont thin it to saturate the wood, you want to encapsulate...

 

[Woodonglass]

Poly, Poly, Poly!!! Oh did I mention you should use POLY!!!!

 

[sphelps]

If you have 2 gal of epoxy there are ways you can use those up then switch to poly for areas you may want to gell coat ..
You could do just the stringers or anything below deck then do the rest of the topside with poly .. You would just need to use epoxy to glue the new decking to the epoxy stringers .. As Scott said poly doesn’t like to stick to epoxy but epoxy will stick to everything ... So any areas you may want to gell coat you do not want to use epoxy .. If epoxy you would just paint ...

 

[Scott Danforth]

I personally prefer poly for hull restoration, and epoxy for coating the wood prior to upholstery