Stringer Bedding Question

[baylor]

I have an old boat that I am trying to put a new floor in. It's a 15 1/2 foot Browning pleasure boat with a Chrysler outboard. After I cut the old floor out the stringers were of course rotten also. There are three of them,they start just in front of the seats, the two outside ones are 9 feet long and run to the transom, the middle one is 8 feet and butts up against the box where the drains are (not sure what its called but it's rotten also). My question is what should I bed the new stringers in to keep them from touching the hull, they look like they're about a 1/4in from it now.Would construction adhesive work ok? Someone told me to do that. Once they are in place I plan on completely glassing them in although they originally just glassed in places. Thanks in advance for any help you can give me.

 

[TheWoodCrafter]

Re: Stringer Bedding Question

Welcome baylor.
I'm a green boater too.
But you will find lots of help here from these experts.

Why would you not want the stringers to touch the boat shell?
I would think a better fit to the hull would make things stronger.
I think you are going to have to decide if your going back with polyester resin or epoxy. I would think mixing whatever you decide to use with a thickner would be the way to go, then completely glass them in. If the fit is better it would take a lot less material and add less weight.

 

[fuzzeywiggler]

Re: Stringer Bedding Question

Welcome baylor.
Why would you not want the stringers to touch the boat shell?
I would think a better fit to the hull would make things stronger.
less weight.

You dont want to glass the stringer directly to the hull! You won't be able to make it fit uniformly to the hull so you will put stress in places it shoulden't be. Bed it in PB or a Pl 4200 (I think)
Good Luck! also check your transom for rot.

Fuzzey

 

[TheWoodCrafter]

Re: Stringer Bedding Question

You dont want to glass the stringer directly to the hull! You won't be able to make it fit uniformly to the hull so you will put stress in places it shoulden't be. Bed it in PB or a Pl 4200 (I think)
Good Luck! also check your transom for rot.

Fuzzey

I see.
Good to know.
You see, I learn something from you guys everyday.

 

[tashasdaddy]

Re: Stringer Bedding Question

i use PL premium.

 

[baylor]

Re: Stringer Bedding Question

Thanks for the help. I've checked the transom by knocking on it and trying to stab an ice pick in it. It appears fine. I looks like they sprayed it on the inside with some kind of black sealer to protect it.

 

[Coors]

Re: Stringer Bedding Question

I'm biased, after using epoxy, after years of using poly, which is a pain.
It costs more, but less pain involved.
Resin won't stick to PB.
Epoxy sticks to everything, including your cat.

 

[cprince]

Re: Stringer Bedding Question

You dont want to glass the stringer directly to the hull! You won't be able to make it fit uniformly to the hull so you will put stress in places it shoulden't be. Bed it in PB or a Pl 4200 (I think)
Good Luck! also check your transom for rot.

Fuzzey

What is PB and/or Pl 4200?

**EDIT**
What is the bedding process? Is there a good FAQ or good thread that you know of on this type of thing?

Found it at the bottom of this page showing related threads! What a site!! But I am still not sure what PB and/or Pl 4200 is yet...

TIA!

 

[Robj]

Re: Stringer Bedding Question

Make a peanut butter mixture from whatever resin you will be using to glass in your stringers. I don't see the benefit of using construction adhesive when resin will not stick to it. With epoxy or poly based peanut butter it will not be an issue.

Have a great day,

Rob.

 

[fuzzeywiggler]

Re: Stringer Bedding Question

P/B is a mixture of your resin and a filler (wood flour, milled fibers ect) it is used to make fillets (fiberglass dosen't do corners) and to bed things (stringer) you use it because resin on its own does not have any strength.

Fuzzey

 

[baylor]

Re: Stringer Bedding Question

What size roving should I use on the stringers? Like I said before they were'nt completely glassed in before. It looks like they laid a piece of 18 oz. roving over them in about 6 inch intervals. Must have been a Friday afternoon boat.

 

[ondarvr]

Re: Stringer Bedding Question

For this repair it won't make any difference whether you use polyester or epoxy resin and you'll never be able to tell the difference in the future.
Just find a local place to get your supplies if you can, this makes it easier than waiting for stuff to be shipped.

If all they did was tab in the old stringers, then that's all you need to do to build it back to it's original strength, for the wood to last longer though, cover them completely with glass. Again the glass you use isn't going to make a big difference either, 18 or 24 oz roving will work fine and so will Biax, just use what fits your budget and you can find. Mat needs to be used as the first layer, and between each layer of roving for it to bond well if you use polyester resin.

 

[baylor]

Re: Stringer Bedding Question

Do I need to let it dry and sand it between layers or does it matter and how many layers should I use? It only has has one on it now.

 

[ondarvr]

Re: Stringer Bedding Question

One layer of mat and roving should do it and you put both on at the same time. The hull needs to be well sanded (36 grit on a grinder) and cleaned before doing any glass work though.

 

[Reboot11133]

Re: Stringer Bedding Question

Just out of curiosity, what type of wood is recommended for the stringers? I have a 16' Bayliner Cutty with 2 stringers which are 1"x4"x8' rotted something...
I was going to use red cedar because it won't rot in my lifetime but a neighbour tells me it is not a structural wood.

 

[Coors]

Re: Stringer Bedding Question

Fir, and if you build it up to 3/8" thick, you don't care if it rots again, the glass is the strenght now.

 

[Reboot11133]

Re: Stringer Bedding Question

Thanks for your input.