Bedding the stringers

[jeffrey.bean]

New transom is in, now on to the stringers. Is it ok to bed and fillet the stringers with polyester PB, then tab and wrap with epoxy? I have enough epoxy to tab/ wrap, didn’t want to buy any more if I can help it. Doing the sole in poly, so I have that on hand.
Also, what material should I use to elevate the plywood stringers off the hull?
And the whole idea of that is, to not let the wood contact the hull, correct???

 

[88 Capri (2022 SOTY)]

New transom is in, now on to the stringers. Is it ok to bed and fillet the stringers with polyester PB, then tab and wrap with epoxy? I have enough epoxy to tab/ wrap, didn’t want to buy any more if I can help it. Doing the sole in poly, so I have that on hand.
Also, what material should I use to elevate the plywood stringers off the hull?
And the whole idea of that is, to not let the wood contact the hull, correct???

Hi Jeffery,
Your first question I can't answer but I do know there are threads on the subject of epoxy/poly, I have not used epoxy so I don't want to take a guess and lead you down the wrong path.
In regards to your second question I didn't physically raise my stringers off the hull because my boat is small and it would have created many issues for me. I am not concerned about them in this way though because they are bedded with PB and wrapped correctly (factory only covered them half- way) so rot was inevitable!
I do recall some people shimming the stringers slightly off the floor so the wood wasn't contacting the hull and the PB filled the void under them so they were encapsulated in glass and maybe it would add more strength with the PB under them, I'm curious on this.
I'm sure either will be fine because you will be doing it the right way

 

[jbcurt00]

Elevate the stringers, only enough that the PB is under it creating a 'foot' when coved to the stringers,


Makes the PB be continuous 1 side to the other and acts as a footer to spread load across the hull evenly, not in 3 seperate pieces: left side PB, right sid e PB w hard edge of plywood in between

 

[zool]

Yes its fine to tab with epoxy over poly bedding, in fact, every time you put epoxy on a hull, you are covering poly with epoxy by default.

 

[jeffrey.bean]

Hi Jeffery,
Your first question I can't answer but I do know there are threads on the subject of epoxy/poly, I have not used epoxy so I don't want to take a guess and lead you down the wrong path.
In regards to your second question I didn't physically raise my stringers off the hull because my boat is small and it would have created many issues for me. I am not concerned about them in this way though because they are bedded with PB and wrapped correctly (factory only covered them half- way) so rot was inevitable!
I do recall some people shimming the stringers slightly off the floor so the wood wasn't contacting the hull and the PB filled the void under them so they were encapsulated in glass and maybe it would add more strength with the PB under them, I'm curious on this.
I'm sure either will be fine because you will be doing it the right way

Hi Jeffery,
Your first question I can't answer but I do know there are threads on the subject of epoxy/poly, I have not used epoxy so I don't want to take a guess and lead you down the wrong path.
In regards to your second question I didn't physically raise my stringers off the hull because my boat is small and it would have created many issues for me. I am not concerned about them in this way though because they are bedded with PB and wrapped correctly (factory only covered them half- way) so rot was inevitable!
I do recall some people shimming the stringers slightly off the floor so the wood wasn't contacting the hull and the PB filled the void under them so they were encapsulated in glass and maybe it would add more strength with the PB under them, I'm curious on this.
I'm sure either will be fine because you will be doing it the right way

Hi Jeffery,
Your first question I can't answer but I do know there are threads on the subject of epoxy/poly, I have not used epoxy so I don't want to take a guess and lead you down the wrong path.
In regards to your second question I didn't physically raise my stringers off the hull because my boat is small and it would have created many issues for me. I am not concerned about them in this way though because they are bedded with PB and wrapped correctly (factory only covered them half- way) so rot was inevitable!
I do recall some people shimming the stringers slightly off the floor so the wood wasn't contacting the hull and the PB filled the void under them so they were encapsulated in glass and maybe it would add more strength with the PB under them, I'm curious on this.
I'm sure either will be fine because you will be doing it the right way

Thanks 88 Capri, thanks for the input. My stringers only have a layer or two of CSM,in some areas none.
I’ll be using 1708, so should be much better than factory.
I know you can go over poly with epoxy, but not vise versa, so I should be good ( my famous last words, lol)

 

[88 Capri (2022 SOTY)]

Yes its fine to tab with epoxy over poly bedding, in fact, every time you put epoxy on a hull, you are covering poly with epoxy by default. 

Yes its fine to tab with epoxy over poly bedding, in fact, every time you put epoxy on a hull, you are covering poly with epoxy by default.

I am looking in the mirror saying DUH right now!

 

[jeffrey.bean]

Would I add wax to the polyester used for the fillets, let cure, then sand in prep for the epoxy, or would the epoxy still bond to laminating resin?

 

[zool]

You want to apply the epoxy tabbing over fully cured poly PB, no wet on wet. You dont have to sand for adhesion, because of epoxys glue properties, but it helps the mechanical bond. You would want to at least sand off any ridges or nibs so u dont get too many air pockets under the cloth.

 

[jeffrey.bean]

You want to apply the epoxy tabbing over fully cured poly PB, no wet on wet. You dont have to sand for adhesion, because of epoxys glue properties, but it helps the mechanical bond. You would want to at least sand off any ridges or nibs so u dont get too many air pockets under the cloth.

10-4, thanks