Sailboat Keel sump reinforcing

[jkondz]

Gents,

I am new to the site but have spent much time here researching in the past. Finally have a project worthy of posting. I am rebuilding the keel sump to my sailboat. The keel has some wiggle and I would prefer it not have ANY!

Pic below to help out

1. Keel sump is hollow for 18" down.
2. Chord length at top of opening is roughly 4'
3. Boat is 32' long and weighs 4850 lbs with ballast
4. Ballast at bottom of keel is 1800 lbs
5. Keel sump currently has rotten stringer that I will remove 100%
6. Keel width at bottom of sump is 4-5"
7. hull is poly with foam core
8. boat originally built 1983

My thoughts.
-remove all of the existing strings in the keel sump
-grind and prep area to expose good glass
-degrease x10
-lay in 3-4 layers of 1708 fabric as in pic below extending from inside the sump 2' either side in the bilge
-glass in several stringers made of 3/4 marine ply (coated in resin) with more 1708
-pour a layer of resin mixed with cabosil and chopped strand in bottom to give keel bolts level surface to tighten to

concerns
-1 stringer that I am going to remove was tabbed in with epoxy. I can probably get 90% of any epoxy out
-highly loaded part of the boat

questions
The age old question, should I use poly, VE or epoxy?
how many layers of glass would you recommend? would something other than 1708 be better?

fire away gents, thank you in advance. I will post pics next time I go to the boat to show removal and prep work.

 

[chconger]

Re: Sailboat Keel sump reinforcing

Hi There

1; What kind of boat you go there?
2; have you confirmed the core is not compromised in the hull, adding to the wiggle?
3; Have you talked / compared to other owners to see if this is common?
4; have you determined the "hinge" point for the wiggle
5; How much wiggle are we talking about?


You looking to have the glass take a considerable load there. I would say epoxy and heavy roving.

I don't see the stringer in your drawing and cant imagine quite where this would be...pictures will be great.

 

[jkondz]

Re: Sailboat Keel sump reinforcing

Please see below

Hi There

1; What kind of boat you go there? Evelyn 32-2 sailboat
2; have you confirmed the core is not compromised in the hull, adding to the wiggle? Not yet
3; Have you talked / compared to other owners to see if this is common? Common issue for this design
4; have you determined the "hinge" point for the wiggle Have not,
5; How much wiggle are we talking about? Not much wiggle, mainly doing it as preventative measures and boat will preform better if it is solid.

The keel wiggle is common to this design of boat. Many owners have added stringers to solve this issue. I am doing this more for piece of mind. My main question is will Vinyl Ester or Poly work or should I go with epoxy? Second question is how much reinforcing would be appropriate without creating hard spots and simply transferring the problem area from one spot to the next.

As I originally stated I believe 1 stringer was tabbed in with epoxy by the previous owner. I feel as though during demo I can remove 90% of any eopxy from the area.

some owners have posted that they used epoxy, the same owners also used epoxy to replace core on the deck and apparently have no budget. Others have not listed what they used



.


You looking to have the glass take a considerable load there. I would say epoxy and heavy roving.

I don't see the stringer in your drawing and cant imagine quite where this would be...pictures will be great.

I have attached pics of other peoples rebuilds. in various stages. Before, after demo, and after new stringers glassed in.

 

[jkondz]

Re: Sailboat Keel sump reinforcing

Where are all the gurus at. Paging fiberglass doctors.

 

[chconger]

Re: Sailboat Keel sump reinforcing

Sorry for the delay...I had something typed out at home last night and my PC decided to go wonky, went to bed


Anyhoo

This looks like the way to go

At least two "T" bulkheads going down into the well and up across your hull. I would make it from laminations of BS1088 marine ply, totally encapsulated with epoxy. Heavy tabbing / glassing out from it to the hull to sperad the loads and avoid hard spots.

Your going to need to accommodate bilge pumping down there, so may want to allow a small channel at the bottom of each T.

I don't think just adding glass as per your initial drawing will do much without a bulkhead. Bulkheads are in boats for these reasons.

You wont regret using epoxy.

Cheers
Chris


PS - Nice looking boat