Trotter Keel Case Replacement and Shaping of Centre Board

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paul trotter
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Trotter Keel Case Replacement and Shaping of Centre Board

Postby paul trotter » Mon Jun 08, 2009 9:35 pm

Okay Careelers,

I've been talking about it at the Nationals and the following months and I just couldn't face doing it again. There just was so many sailing events on this time of the year!

On the Monday (today) straight after another defeat or third place under the hands of David Dowling in Therapy the time had come for it to come out.

With the boat now housed at Moggill, the table top was removed this morning with the new SS screws coming out easily. (The table had come off the day before the Nationals and all the old corroded screws replaced).

A couple of hydraulic jacks and some small pieces of timber and up came the keel. Two big G clamps, two big boys, heave ho, crunching of back and out she came to be deposted on some cushions in the cockpit. A transfer then on to a trailer and then across to a couple of wooden horses.

The condition after pretty constant use after about four years was perfect. No sign of rust and a good layer of galvanising remaining.

Unfortunately the same cannot be said of the keel case. (The real reason its coming out). I put my finger in the pin hole and all I could feel was goo! Strangely the other side felt solid and a probing finger only revealed a rough timber edge! Any suggestions on how I should treat this side to keep it in good shape - what sort of goo should I shove in to seal up the edge of the play as the hole will be an ideal template for the other side and the ply all seems to be in good shape. Should I just let it dry out and fill it with waterproof silicon?

So now over the coming months just like Cookie you will get a blow by blow description of the keel case repair and the shaping of the 12mm plate. I hope you will all find it amusing and fee free to offer your advice.

Next weekend I plan an assault on the keel case with an angle grinder. I will unscrew the remaining fittings and pulley system. Then I'll cut a long rectacular hole all around the ply right down to the false floor. I then hope to peel it away and then attack the remaining rotten ply from above and remove it all the way down to the edge of the skeg. (I remember doing this work with Cookie on Ivana and that would have to be the worst part of the whole excercise).

Stay tuned....

I am now officially a crew member for anyone caught short.

My goal is to have keel shaped and replaced and a new rudder prior to the Spring Series and Queensland Titles to be held on Lake Samsonvale.
Attachments
keelstart.JPG
keelstart.JPG (324.22 KiB) Viewed 6124 times
Last edited by paul trotter on Wed Dec 22, 2010 5:43 pm, edited 10 times in total.
Paul Trotter
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Epoxy mixed with Graphite on Plate

Postby Leerac » Thu Jun 18, 2009 7:42 am

Graphite Paul , Graphite, :lol: you racer you !
I've given you the clues now go for it
(Bundy Bruce)
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paul trotter
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Further Developments

Postby paul trotter » Thu Jun 18, 2009 9:39 pm

Thanks Clayton for getting us back on line.

I can now up date on progress.

Last weekend the boat was emptied, the angle grinder readied and then came the damage.

After a quick update telephone call with Cookie I was briefed to use a diamond wheel and to go for it!

I put on the goggles, face mask and cloves and worked all around the starboard keel case cutting a big grove almost all the way round from top and as close to the floor as possible. The ends caused a few problems as its impossible to get the angle grinder with a diamond wheel into every last corner.

The fibreglass bubbled forward with the internal ply cracking open like a clam! In went the screw driver and with some gentle encouragement and leaverage the facing piece of fibreglass with some ply laminates came loose.

Out came the vacuum cleaner to clear the boat of toxic dust and then out came the chissle to scrap away the ply. While the ply showed some stickiness and sponginess in places it was mostly just delaminated. The water had worked along the delaminations right along the case towards the stern from the pin.

After the scraping I bagged the ply and cleared the floor. There is now about 3 inches of ply left between the false floor and the keel. This was going to be difficult. My father suggested the use of the angle grinder again with a saw like attachment. This worked pretty well as I was able to wedge the grinder hard up against the remains of the case and go crazy! There was saw dust everywhere and another vacuum.

This removed another inch off the plywood with another two inches to go!

Out came a drill with a scabbled bit and I have removed most of the ply around the pin.

Its now holiday time so work has been abandoned until mid July.

Any easy machanised solutions for the remaining ply? This is going to be a real pain!
Attachments
Keel grind.JPG
Keel grind.JPG (373.66 KiB) Viewed 6123 times
Last edited by paul trotter on Sun Aug 16, 2009 8:56 pm, edited 1 time in total.
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Re: Further Developments

Postby careeled » Fri Jun 19, 2009 1:46 pm

paul trotter wrote:Any easy machanised solutions for the remaining ply? This is going to be a real pain!
There's a thing called a Fein Multi-Tool, made in Germany, and highly praised by shipwrights, tradies, high-end handypersons and the like. Downside is it will set you back about $500-600.

However, Bosch has come out with a cheap knockoff, around $140.

Rather than rotating, the head oscillates, so it can get into tight spaces much more easily. Not sure if it will suit your needs or not, but may be worth a look at.

There's also some magic epoxy stuff that can be used for treating timber that's starting to rot, or to prevent rot. It's called CPES, and you can read more about it here:
http://www.rotdoctor.com/products/cpes.html
http://www.senseal.com.au/products/mult ... rview.html

Learnt about this from our builder, who was fixing some rotten door/window frames. You don't use it for the really rotten stuff, but once you've cut that out, you treat what's left behind with it. Very volatile; it will leave you with a headache, and will take a few days to cure, depending on the humidity.

As an experiment, we put some on some totally rotten timber (like wet cardboard) -- and which isn't recommended. It certainly strengthened it up a lot, though it was quite brittle.

Oh and it also strips paint, so mind where you splash it.

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Re: Further Developments

Postby maxm » Fri Jun 19, 2009 3:56 pm

careeled wrote:However, Bosch has come out with a cheap knockoff, around $140.


This is the Bosch blighter:

http://www.bosch-do-it.com.au/boptocs2- ... t_id=95226

Most of the Bunnings in my area stock it, although they don't seem to stock the blades yet! :?
Max
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Remaining Plywood

Postby paul trotter » Mon Jul 20, 2009 9:20 pm

Dear Max and co,

I did the research on the Bosh gadget but my older brother came up with a better idea.

We got a 10mm diameter one metre long piece of reinforcing rod and just belted the ply out using the blunt end and a hammer after the initial chisel work around the pin! Very effective and very fast!

Ply is now removed.

Any suggestions on a ply substitute ie like nylon cutting board material (may not bond to fibre glass?)

Cheers
Paul Trotter
Nellie C18/472
Vice Commodore North CCYA

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Postby jamesw » Tue Jul 21, 2009 8:21 am

be careful with plastics that may get wet, apparently they can absorb moisture, just like ply!

there's a guy, Chemikaze that used to post on Trailer Sailer Place, do a search on his name, he has a heap of good info on stuff like this.
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Progress

Postby paul trotter » Tue Aug 04, 2009 5:59 pm

The ply was purchased last weekend and I now have a big bit of 12mm thick marine grade maple hwd ply.

This weekend I cut out the ply to shape and treat it with an expoxy sealer. I would also like to cut an oversized hole for the pin and infill with fibreglass to ensure all the end grain of the ply is sealed.

I have also bought the 4mm marine hoop pine ply for each side of the 12mm steel plate that needs to be cut to size and treated. I hope to acheive both tasks this weekend.

ON Ekka Wednesday I hope to reinstall the ply case and have that clamped and cluing in my absence.

The following weekend will be taken up with keel shaping and timber trim work.
Paul Trotter
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Postby peter connor » Tue Aug 04, 2009 6:35 pm

Paul

Under the topic of keel shaping you should replace the word weekend with the word weekends.

Regards

Peter Connor
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Weekends?

Postby paul trotter » Tue Aug 04, 2009 9:44 pm

CORRECT Peter!
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Keel ply back in and cramped

Postby paul trotter » Sun Aug 09, 2009 7:04 pm

Progress report:

I started work again just after lunch on Saturday by assembling the range of purchased epoxies and fibreglass on the work bench.

The next step was to cut out the correct size piece of 12mm ply with a jib saw. I took some width dimensions along the keel case using a narrow steel ruler lodged in the bowels of the keel up to the underside of the table with the dimensions varying slightly from 610mm at the bow end and 595mm at the stern with a small bulge mid way (Its not a straight line).

I then used the fibreglass that had been removed as a template to mark up the piece of ply and went mad with the jig saw. After about three attempts and some shaving of the bottom of the new ply I got her into the slot. The keel case had warped considerably after two weeks of drying out. I then used a pencil through the keel hole on other side of the case as a template to mark the pin hole.

After cutting I gave it all a good sand back especially around all the edges. Then on went the Epicure using a disposable brush and 50% number 7 epoxy thinners. During that evening I gave it 4 coats progressively using less thinners. I had it laid out on bricks and left it about an hour between coats. That evening I also chisseled out and sanded back the fibreglass that had been covered the ply keel case framing. This was to remove the last of the rotting plywood.

On Sunday morning I used the chisel on the keel case to also remove the last of the fibre glass and some vacuuming For good measure I also gave both bits of fibre glass a coat of 30% thinned Epicure and then a light sand to stable any last vestigages of ply I couldn't remove.

I then did a dumby run to fit the ply and the fibreglass cover and used some G clamps to secure the top of the case and some blocks and wedges to secure the bottom. To keep the keel case shape I inserted some pieces of 12mm play which stopped the cavity from being crushed shut. All good.

Now for nerve wracking bit. I mixed up a large portion of two part Epiglue in an icecream bucket and then proceed to trowel it on to the keel case in the boat with the fan running so I could breath. (It wasn't too bad).

After completing just this side I ran out of glue and had to repeat the process and then apply it all over the newly prepared and cut piece of ply. I gingerly then pushed the ply into position and she fitted beautifully. (I had also run out of glue again and decided to only do one bond at a time).

So with much cursing the clamps were put in position and the alignment checked. It all looks pretty good.

A still have some concerns......

Did I get the mix right? The Epiglue is so viscous that it won't sink in the bottom of a measuring jug and the hardener is almost like jelly and even worse. I ended up using a spatchelor to scope up four scoops of Part A and two of Part B. After four hours the mix left in the bucket was still jelly like so I pray she sets properly.

I also placed in the pin hole the stainless steel sleave and used Epifill to seal all around it on both sides as it is a snug fit in the ply. On installation of the ply I need to knock her in a bit more so I might loose some waterproofing. I think to resolve the situation I might cover the hole end of the pin with Epifill and along with the perspex covers, screws and silicone I will acheive an effective seal.

The Centre Board

I took the necessary measurements to see how much more timber edging I can glue to the Board to create a curved leading edge and tapered trailing edge.

I have only about 8mm available at the front and remove 2mm for fibreglass so a 6mm bit of hardwood will be glued to the front face. The trailing edge I only have 20mm to play with and I don't want to take much more out of the back of the table.

So on the public holiday on Wednesday I hope to finish the keel case and start some reel work on the Centre Board! Lets hope that glue has cured and all is good when the clamps come off!

Cheers

Trots
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Case nearly complete

Postby paul trotter » Thu Aug 13, 2009 1:34 pm

Written Wednesday Night

Today I made some great progress. I arrived at Moggill to find the
ply had bonded well to the side of the keel case. On
removal of the clamps and blocks all looks good. The glue was very
hard in all areas examined.

I fear one error as I used 12mm ply in two layers to pack out the case
which is only 24mm not the 25mm of the keel case. The ply slipped in a
little too easy with a small 1 mm gap along the base between the ply
and false floor.

The next step was to glue on the facing piece of fibreglass and while
doing the job I took the opportunity to pack to 1mm gap with Epiglue.
It all went on nicely and I had enough Epiglue to fill three sides of
the installation. I will come back later and do some more
fibreglassing along the ply and the false floor. The newly installed
fibreglass panel was then clamped and chocked.

Next after lunch was the work on the keel. My intention is to shape it
to create a nice flat aerofoil to make me go fast like Don Ray and
that Wearing guy! This will involve some added ply and fibreglass to
the existing rectalinea keel plate.

To start I need to cut some seasoned spotted gum for the front and
trailing edge. This was cut using a circular saw to create two
pieces. The leading edge at 14 x 6mm and the trailing edge at 14 x
20mm. It was interesting to discover that the keel was 14mm thick not
12mm as anticipated. This probably had something to do with the hot
dip galvanizing I had done a few years back. I put the timber aside
having decided to deal with the keel ply attachments next.

This in theory will mean bonding 4mm ply to each side of the keel.
let's do the maths. 14 + 4 +4 =22mm. Keel case is probaby now 24mm.
That's only 1mm tolerance each side including the fibreglass shell.
The nylon plastic shimmies that stopped the Keel sloping around were
5mm. I wonder if it will now fit after my potential case reduction?
This will all need to be checked and verified before I do the final
outer shell of glass on the keel.

Instead of having to pick up the keel I elected to do a two stage
installation of the ply outer layer. The keel at present is sitting on
two wooden horses. I layed out the 4mm ply on top deciding to cover all
of the bottom of the keel but leaving it partially cut at the top to
make room for the nylon shimmies.

I used the keel as a template and then cut the ply to shape using a
jig saw. I then cleaned the keel down with number 7 epoxy primer after
removing the nylon shimmy that was attached to the bottom of the keel.

The leading edge of the keel was slightly thinner and pitted due to
some earlier corrosion so some extra Epiglue was applied. I then mixed
the last of my Epiglue and trowelled on to the keel and then the ply.
Then I lowered the ply on top and threw on every brick and block
I could find on top to weigh it all down.

All looks good but I'm still concerned about the keel case thickness
that will need to be checked thoroughly and a jig made up to confirm
the new keel thickness prior to installation.

This weekend I hope to apply second piece of ply, timber edges and
most of the shaping. The weekend after I will glass the lot with the
keel then lower back into the boat the following weekend at the end
of August.
Attachments
Keel clamp.JPG
Keel clamp.JPG (275.38 KiB) Viewed 6119 times
Keelnewply.JPG
Keelnewply.JPG (260.82 KiB) Viewed 6121 times
Last edited by paul trotter on Sun Aug 16, 2009 9:01 pm, edited 2 times in total.
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Postby Leerac » Thu Aug 13, 2009 5:16 pm

How bout some photos Admiral.
Wait til ya see me rudder ! Cup looks safe !
(Bundy Bruce)
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Postby maxm » Thu Aug 13, 2009 7:51 pm

Hey Paul,

Cool!

Now don't forget that all important boundary layer between keel and water. We've discussed it here before, remember? You can seriously cut down drag by using dolphin skin. I guess whale skin will probably also work provided you don't get a bit with barnacles all over it. Leather keel case? Now that's cool!
Max
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paul trotter
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Rudder?

Postby paul trotter » Thu Aug 13, 2009 8:24 pm

Hey Bruce,

I have taken some photos and will post them up soon.

As for rudders...you don't have a chance.

I just paid the deposit on a Castle 550 rudder from Yacht Works Victoria.

It will be very shiney and white and just as devastating!

I'm hoping to have all operational before the Great Clarence State of Origin Clash! Are you coming along for this event Bruce?

We also need to reset the date for the Queensland Titles.

Max i think dried dolphin skin is an excellent suggestion!

I see Mr Wearing will stop at nothing and has purchases some light but bugged motor for the transom...I bet he only carries one litre of fuel during the nationals and tops up every day!
Paul Trotter
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