Cast iron / wood keel replacement.

[Nikki B]

Hi I'm about to reaffix my keels on a 19' Caprice.
There's the cast ballast keel then a wooden section bolting on to the fiberglass hull.
On an other thread it says to use bedding compound and a gasket. What bedding compound and what would the gasket be made of?
Presumably there would be one between both the iron/ wood and the wood/ hull?
Any advice please?

 

[Nikki B]

Hi I'm about to reaffix my keels on a 19' Caprice.
There's the cast ballast keel then a wooden section bolting on to the fiberglass hull.
On an other thread it says to use bedding compound and a gasket. What bedding compound and what would the gasket be made of?
Presumably there would be one between both the iron/ wood and the wood/ hull?
Any advice please?

 

[Nikki B]

Bump.

 

[lw395]

Well I've bolted iron keels to wooden boats and to grp boats, but a mixture of the two is a new one.
You are trying to achieve two things.
1) not let water into the boat
2) not have the keel bolts corrode

1) I think means a good seal is needed around the bolts where they enter the hull. Gasket and bedding compound should do this
2) Well I don't think you'll keep the keel bolts dry in the wooden section? so sealing between wood and iron does not achieve much? Unless the wood section is totally sealed in epoxy, then gaskets top and bottom with sealing compound?

Normally on wooden boats the bolts are big and the loads are small, so they corrode for 40 years and are still strong enough.
Or they're made of gunmetal or something.

 

[Nikki B]

Hi thanks for the reply.
It probably is unusual but thats the way they are.
The boat is 40 odd years old and the wood had rotten and some of the bolts were getting rather thin. One of the keels buckled when I was dragging it up the slip on rollers.
I have made new wood and sealed it with epoxy but I think you are right that the most important seal is whre the bolts enter the hull.
So my questions are, what is a gasket made from? And what sealet to use. Must it be the expensive 5200 marine adhesive sealent or is there a cheaper alternative?
Keeping in mind the boat is not worth much and the repair has cost a lot already.
It probably wasn't worth fixing up at all but I do love her and we hve had so much fun in the past

 

[lw395]

I'd really like other opinions, but I would probably use a polyurethane sealant, maybe not labelled 'marine'.
The purpose of the gasket, I would see as not squeezing all the sealant out of the joint around the bolts, so it has clearance around the bolts which will be full of sealant.
I might make the gasket of something like 2mm to 3mm neoprene sheet, solid not 'foam neo' wetsuit material.
You might get someone with direct experience on the classic/wooden forum?

 

[johnlilley]

Quite often paint or bitumen soaked canvas would have been fitted between the iron and wooden keel as a bedding gasket. You could probably use car body under seal as a substitute. Between the grrp and wood some form of flexible bedding compound, not silicon though. Perhaps an ms polymer type or butyl rubber. Polyurethane might also work. Some of the modern compounds have exceptional grip so just be sure you do not intend to remove at any time in the near future otherwise use a non setting compound.

 

[Rum Run]

I would be looking at something like CT1, Puraflex 40, or Stixall as an adhesive / sealant and would buy from Toolstation or Screwfix most likely. You won't be getting those joints apart in a hurry.
Traditionally these sort of things were bedded in lead putty or Stockholm tar with a layer of felt (like old roofing felt I think) giving some cohesion in the gloop layer. I'm not sure why you would need a gasket in this instance?

 

[lw395]

I would be looking at something like CT1, Puraflex 40, or Stixall as an adhesive / sealant and would buy from Toolstation or Screwfix most likely. You won't be getting those joints apart in a hurry.
Traditionally these sort of things were bedded in lead putty or Stockholm tar with a layer of felt (like old roofing felt I think) giving some cohesion in the gloop layer. I'm not sure why you would need a gasket in this instance?

I'd not disagree with that.
I think the purpose of the gasket is to avoid squeezing the joint to zero thickness when you do the bolts up.
If the sealant is squeezed too thin, it cannot flex very far before peeling.

 

[DownWest]

Apart from the above, I would use Sikaflex 11FC a PU mastic glue from B&Q et al. Quite cheap and bed the keels in a thickish layer, but not tighten up the bolts until a day later. Just enough to squeeze a bit out all round and let it go off. Then nip them up. This would give you a bedding + sealer. It really does stick well, to just about anything.

 

[ghostlymoron]

Sticks well if you use Sika primer.

 

[Nikki B]

Apart from the above, I would use Sikaflex 11FC a PU mastic glue from B&Q et al. Quite cheap and bed the keels in a thickish layer, but not tighten up the bolts until a day later. Just enough to squeeze a bit out all round and let it go off. Then nip them up. This would give you a bedding + sealer. It really does stick well, to just about anything.

That sounds good to me!
I think that I will have to offer the wood up to the keel to get the shape uf the hull .
Then shape the top face with a spoke shave or mabe just a sanding disk. It is of course curved to the shape of the boat and has an angle on it which I suspect changes over its length.
Depending how this goes it may even be neccesary to coat the face with epoxy putty. Then lightly bolt it on before removing it the next day. ---And then--- bed it down.
Both keels need to be at the same angle of course.