Keel reinforcing

rhumlady

rhumlady

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Hi, I am refurbishing my Westerly Konsort and having problems due to inept Previous owners, probobly the first one who bought it as a hul and deck kit! I only found that out after purchasing it. The currengt trial is with the web above the keel. Someone has tried strengthening it. The two fore and aft pieces have been braced with wood, but not right to the hull and where they cross the thwartships member these have been cut to allow the longer pieces to fit. the whole lot was badly glassed in with glasscloth and epoxy which was put on without cleaning up the existing grp. I am removing the wooden pieces and thinking of cutting out the existing cross members and redoing them properly using 1" or 1.5" foam core. I also intend to use 1" foam slab to redo the reinforcing.
Any coments on this would be welcome.
 
I suggest you try the Westerly owners association forum and their Yahoo discussion group. You can access both from the WOA website and both are available to non members.

http://www.westerly-owners.co.uk/

I was recently looking at some detailed drawings on keel reinforcement for the Centaur among the Photos on the discussion group site. They may give you some ideas and there may be some info relating to the Konsort there somewhere.
 
G'day Derek,

Any chance of a picture?

Sounds like a very armature fix alright, I will never understand why people insist on placing timber in a bilge.

Using foam is an excellent alternative but I think I would be going for an 'A' shape with a rounded top, easy to lay up and very strong; I would also be checking how much clearance I had between the the work and the underside of the cabin sole with a view to building up so that it also supports the sole boards.

I'm not familiar with the layout, do you have any keel bolts in the area?
I searched the net but found no pictures.

Not quite sure how you plan to use a 1 inch foam slab to redo the reinforcing, can you elaborate on this.

We have done a few keel repairs, even did one at sea during a race once, everything got covered in dust but we made it back OK.

Avagoodweekend......
 
A few Westerly designs used glassed in ply to strengthen the keel mounting, which isn't flexible enough and led to problems of delamination.

Very few would have survived this long without being re-done with glassed over foam.

Advice from a good surveyor and a proper job well prepared (unlike the previous effort) should be the order of the day.
 
Thanks for the replies. I will try to get some pics. Whoever did this has ground away some of the glass from the top of the Westerly installed web to allow the floor to fit correctly. They left the Ply showing through! When you say "A" section do you mean shaping the foam? What I mean about the 1" foam was fitting it alongside the existing layout having removed all of the additions. Yes there are keel bolts in the way which are causing problems in cleaning it all up just now.
My problem with surveyors is finding a good one. I am waiting for my son to get back from Sea as he is a graduate Naval Architect who may be able to get some help from the Uni. A project for a fouth year student. This is a fin keel by the way and I believe that the problems Westerly's had were with bilge keels.
Vic, I am a member of WOA but thought I would get more help here. Thanks anyway.

Derek
 
Pics as requested:

DSCF0003.jpg


and

DSCF0006.jpg


(I hope asit's a first for me)

I have to add here that I have had the boat for 11 years and kept promising that I would get her nearer home and do a lot of work on her but I couldn't tear myself away from the West Coast of Scotland.
 
G'day Derek,

It's not difficult to see why so many of these have failed, the pictures tell the full story, that has to be one of the worst keel box arrangements I've ever seen, and as for the botched attempt at reinforcing, well what can I say.

You have some dirty and dusty work ahead of you but the good news is that access looks pretty good so you will end up with a much better and reliable set up.

I suspect the use of ply and not enough glass cover to provide the required strength are the cause of the failures. Removing the glass to help the floor fit was a big mistake, if the ply was stressed to start with because of poor cover, it sure is passed it's use by date now.

Also note the keel bolts themselves seem to lack proper support with almost nothing to spread the load on them.

A well designed keel support system should have more support at the forward and aft ends to cater for grounding and keel strikes, as well good keel bolt support that extends athwartships to support the keel when heeled or when grounding.

Building in some limber holes will also improve drainage and make cleaning easier.

An "A" shaped foam former with a at least a one inch radius at the top and one and 3/4 at the bottom should provide a an easy profile to glass over, add a small gusset at the the contact point to the hull for a smooth transition using a filler.

Keep the top of the foam at least 15 mm below the normal floor board underside level, by the time you finish laying up you should have just enough space to include a protective strip on top to support the board without damaging your new work. (I still can't believe someone ground the top off and left the ply exposed).

I think I would feather the outer laminate rather than add a foam block, your layup (on the outside of the foam) should start at least 18 inches outside the foam, with each subsequent layer around 2 inches inside the last, this will help reduce the effect of a hard spot or sudden change in stiffness, to avoid hull and gelcoat stressing on the outside.

To ensure a good bond I would be using only epoxy resin and cloth designed for use with epoxy, I would also add a layer of roving's as a final topping to the layup, this ensures and stray ends have a good cover and will give a smooth finish to the work prior to adding an extra coat or two of resin and coating to protect from UV.

I hope you keep us all informed with a few pictures of your progress

Good luck

Avagoodweekend......
 
Would you recommend removing the existing box or what? I had thought of just removing the thwartships sections as the lengthways ones are not damaged at all. As I said earlier the problem hulls all had twin bilge keels as far as I know. Why epoxy rather than polyester? I have no experiance with epoxy but have don a few jobs now with polyester.
 
G'day again,

We can only assume the existing box has been correctly located at the points of highest stress, as ply on edge is not a good idea at all I would be replacing it all in this area, rather than worry about it in time to come.

Measure the existing locations and replace them would be the way I would do this project.

As for why use epoxy; any fin keel exerts high stress due to it's small footprint and high leverage when heeled or grounding. For this you need a strong bonding, standard resins rely on the key left after cleaning the surface, an epoxy not only bonds to the key provided but also forms a chemical bond and can be up to 40% stronger.

The fact that you have some experience with standard resins will mean you should have no problems using an epoxy. just remember that you you don't use as much resin with epoxy, roll out as much of the excess resin as possible, epoxy layup is at a ratio of one cloth to one resin, unlike standard resin and chopped strand mat that has a ratio of one mat to 3 resin.

Epoxy has a pot life around 30 minutes or more depending on brand and type of hardener used, never add extra or less hardener to vary the pot life, this will end up a problem, get the right resin and hardener, West System and a slow cure hardener may be the way to go for your first use of epoxy, but it really is not that different from standard resin, and I find it easier to control.

Mix in shallow containers to avoid heat build up, mix small batches, buy a set of pumps to ensure the ratio of resin and hardener is correct, most are 4 resin to one hardener but this depends on brand.

Rolling is done with a small roller made from alloy with a wire handle the roller is about 3 inches long and has a thread pattern on it, available at the place you purchase your resin from.

Epoxy also has better resistance to water ingress so is ideal for bilge work. If you have a other questions about the use of epoxy please ask, there are lots of boaties on this forum who use it everyday like I do, so between us we should be able to answer any questions you have.

have a look at the West System web page and look for the guides on repairs, very good advice available there too.

I hope this helps

Avagoodweekend......







Would you recommend removing the existing box or what? I had thought of just removing the thwartships sections as the lengthways ones are not damaged at all. As I said earlier the problem hulls all had twin bilge keels as far as I know. Why epoxy rather than polyester? I have no experiance with epoxy but have don a few jobs now with polyester.
 
Thanks Brian. The next thing I have to think about then is what to do about the keel. Would I be better getting the hull lifted off or just remove the bolts as required as I go along?
As for your point about limber holes, Wellll they are there having been drilled through and not sealed the water just goes right in and takes days to dry out again. Thinking of this makes your point about starting again more of a way to go.
I have some planning to do now. My lad gets back at the begining of December after 5 months running between Brazil and the Persian Gulf on a refrigerated cargo boat as a cadet engineer. So I will use his Naval arch brains to help and if required he can talk to his old lecturers. It will give him some hands on anyway.
 
If possible Derek I would do the repairs with some of the keel weight hanging to preserve the natural shape and further reduce stress later, do you have to remove the keel at all?

As for the limber holes I would incorporate them into the foam by cutting away a section of foam at the bottom and filling it with micro balloons and placing a small length of electrical conduit in with a one inch overhang at both ends for trimming after glassing. To ensure a bond between the conduit and surrounding material, hit it with a flame hot enough to produce tiny black balls on the surface; this gives a good key and burns off the chemical that prevents it sticking really well. I use this method when building cockpit drains that need glassing.

Avagoodweekend......
 
Morning Brian,
Thanks for the replys. I don't need the keel off, it was just a thought as to how to work around the keel bolts. I am going to have to do some hard thinking about this but I know it is do-able and can only make things better. Apart from this I have one more bulkhead to remove, if it hasn't dropped out by now and then it's on to rebuilding.
 
It's pretty rare to have a bulkhead in such a condition that it has to be removed, are you sure it can't be repaired?

I replaced part of a bulkhead on a 28 footer that had suffered water ingress down one side and part of the bottom. We ran a router through it and made two cuts about 3 inches apart to give us some room to remove the edge left fixed to the hull, got 90% of it out with a hammer and chisel then finished with a grinder. Cut a number of slots in the remaining bulkhead, made a template with 3 mm ply and cut a new suction, glued in place with Gorilla Hair (Micro-Fibres).

Then applied 3mm slats of western red cedar over the whole thing, came up looking better than the original.

Avagoodweekend......
 
The bulkhead is about 18" from the transom and has not been glassed on that side. It could be said that it wasn't glassed on the forward side either. I am going to leave looking in that direction for now as I have enough on my plate with the Keel Box.

Derek
 
Sounds like a collision bulkhead being that close to the transom. The good news is that it probably will never need glassing, a simple clean up, light sanding and you can apply a preserver and top coat with 3 coats of resin wet on tacky and avoid any sanding between coats. It will need a lick of paint when cured.

If you have more information on this we should be able to come up with a good long term fix that won't cost an arm and a leg.

PS this could a good place to use up any left over resin when doing the keel box too.

Avagoodweekend.
 
Brian,

Have you come across Epiglass by International paints? I like the idea of low VOC's, solvent and phenol free. Much nicer conditions to work with.
Derek
 
G'day Derek,

yes Epiglass is easy to use and does a good job; my personal favorite is West System but That's just me.

I suspect I may have used almost every brand of resin available in Australia and a few not available here as well.

The last time i checked there were only 4 epoxy resin manufacturers in the world, but hundreds of distributors, each adding their own additives to "improve" the product, so unless you buying it from a bloke in the pub with no labels on the tins your pretty safe.

I use Micro-fibres for gluing and fillets (like you may need on the aft bulkhead prior to glassing) and 'Q' Cells for filling / fairing, they cost less than Micro Balloons or Micro Spheres, can be used above or below the waterline also.

Avagoodweekend......

PS. Sorry if the reply was a bit slow just got back from a 400 km trip out west.
PPS. Just confirmed my flight for Cairns in January, plan to spend a bit of time on the cat and the great barrier reef with my eldest son, sister and her husband on board.
 
Hi Brian,
and to think I only got a five mile delivery trip with no wind this season!!!. Thanks for the info. I'm going to lookat prices and availability of epoxy this week. I did get one of the cross members that had been cut, removed today. Most of the ply was ok but a big section around the limber hole was not in good shape. I am going to take my time with this and see how it goes.

Derek
 
G'day Derek,

Re:<< prices and availability of epoxy>>
All epoxy resins have a limited shelf life so check container date stamp or best before, also look for a set of pumps to ensure the ratio is correct, pumps make the whole job easy when mixing.

Re: <<I did get one of the cross members that had been cut, removed today. Most of the ply was OK but a big section around the limber hole was not in good shape.>>

One of the problems with using ply on edge is that you are relying the glue joint, no always good, and no surprise you found failures around untreated limber holes. I'm impressed that you plan to take your time with this project, most tend to dive in and make some very odd decisions about materials and methodology, resulting in a finish less than good, a little time thinking spent thinking about what you want and how to get it will save you time and money as well making a better finish.

Just make sure you keep us all informed.

Andavagoodweekend......
 
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