Trotter Keel Case Replacement and Shaping of Centre Board

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paul trotter
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Great feedback

Postby paul trotter » Mon Aug 17, 2009 5:37 pm

Peter,

I'm a little confused...the hardwood timber at each end of the keel is as solid as a rock and won't deform. I plan to wrap three layers of glass around each end to make it even more solid. Am I missing your point?

Luna C

Thats for the information on the Shimms. I still have mine and plan to sand them back half a mil or so each to ensure they still fit. I have cut the ply around these so they run smoothly against the metal keel.

I can't wait to get this machine back on the water and see how she performs!

Cheers
Paul Trotter
Nellie C18/472
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Postby peter connor » Tue Aug 18, 2009 12:50 pm

Paul

If the timber is solid don't worry. When I made centreboards in the past. the trailing edge was very sharp and tampered to a very fine edge. Hence flexible before being glassed.

As for putting back the shims, I had real troubles with this. I finally used a strong sewing thread, eg nylon for leather stitching. From memory I thread the thread through the hole of the shim and over the top of the shim and back through the hole. Then both ends down the centreboard case and through the case pivot hole. I then put the centreboard in and pulled the shim down so that the shim hole lined up with the case hole. The first side is the easiest, the second side is tricky.

Good luck

Peter Connor
C18/370
The Smooth

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paul trotter
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Shims

Postby paul trotter » Tue Aug 18, 2009 5:57 pm

Peter,

Yes I remember what I did last time I removed the keel. I simply used masking tape to wrap around the keel to hold the shims in position and that seemed to work.

It was strange that after about 3 years of wear the existing keel still had the marks and bits of masking tape all over it.

I think I will try the same approach again and see what happens. It wasn't rocket science!

Cheers
Paul Trotter
Nellie C18/472
Vice Commodore North CCYA

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Postby don47 » Wed Aug 19, 2009 3:41 pm

Trotts & Pete.

What I found very quick and easy when re-installing the CB back into the case, was as you say Trotts , using tape to hold the blocks to CB.

However, before installing, if you then cut some tubing or something the same diameter as your pin and a whisker shorter than the total width of the thickness of all three ( 2x blocks and CB ), assemble lot and as lowering down into case pull away holding tapes before blocks dissappear .

You are then free to lower into position and while held in position, simply knock thru your pin , automatically pushing out your made up supporting member.

Don.
Don.

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Postby peter connor » Wed Aug 19, 2009 4:40 pm

Don

Thats the best idea for this problem.

I will try and remember next time I remove the keel in 5 years.

Regards

Peter Connor
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Postby maxm » Wed Aug 19, 2009 5:47 pm

How do you guys ensure that the keel is all squared up and properly in line with the boat? Seems to me that any small misalignment may not be noticed at the pin and would have a nasty effect on performance.
Max
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Postby don47 » Wed Aug 19, 2009 9:34 pm

Max.

In my lucky circumstance the pin holes, ply work in the case, etc, were all in very good sound condition, accepting CB (easy fix ). I did however make sure, as sure as I could be thru leveling and various measurement checks, that the pin location holes were in fact as right as they could be, I had to satisfy myself with that aspect.
There was some small amount of wearing to the pin hole in the CB itself. This was corrected by drilling out and s/steel sleeving, all of which had to be preformed accurately.
Your true indication and test that things are fairly right and on the money, are when the CB is back in the case. If the CB stands nice and vertical and is aligned down the centre length ways, well shes probably all things considered, got to be pretty good.
I'm also now happy with the fact that my CB fits snug the width of the case and no real flex or other twisting action now or in the future should occur causing ware and tear, to board, pin, glass or ply. (it's no longer a 12 mm gal plate allowed to perhaps swing and flop around in a 24mm odd case slot, on the trailer or on the water. )
Don.

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paul trotter
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The home stretch

Postby paul trotter » Sun Aug 23, 2009 7:28 pm

Dear keel watchers,

The keel is coming together nicely and now is coated with one layer of fibre glass on both sides.

It took the day off Friday and spent it sanding the other side and shaping it to perfection. It came out beautifully and according to my plywood template. It did take a number of hours to get right but I found some more abrasive sand paper in the shed that helped things along.

My big concern remains the thickness and that it fits back in the case and secondly the cover of fibreglass.

On Saturday afternoon I glassed the first side and had some fun getting the glass on straight. Those little steel rollers are pretty good but I didn't get many fibres near the leading edge. I realised later that I stuffed up with my epoxy mix with a 1:1 ratio instead of 2:1 as required. This should have had the epoxy cured super fast.

Today I had to wait until about 4pm before I could turn the board over safely and have a go at the other side. I did alot more sanding and used my gig to check the width. It works out at about 22mm with one side glassed. So I reckon I have about 1.5mm to play with. The next sheet of glass won't go near this dimension.

The glass went on better this time as I attacked it immediately with steel roller as I laid it out over the first coat of resin. Problem how ever. About half way through doing the finishing coat the epoxy started to steam and then turn to jelly! A fantastic and interesting sight. Next time I need a shallower bucket but there is nothing like finding out the situation yourself! I got the mix right this afternoon.

So I still have a few questions to ponder over the next few days.

I plan to give both sides a medium sanding to smooth them out and get rid of the lumps and bumps and any residue fibre glass. I will then use the number 7 Epoxy thinners with the resin and apply a finishing coat to both sides and the leading and trailing edge. It doesn't look like these narrow edges will like having the glass turned over the face so extra resin will have to do.

Should I put another layer of glass on? Should I just put a little more glass around the point 150mm below the pin where the keel is likely to compress against the keel case?

But the big question is.....how am I going to get it back in easily. My brother has a small crane and I plan to use the same strapping I use to tie the boat down. This is about 2mm thick. Problem: keel at 22mm plus 4mm of strapping = too wide for the case!

Any suggestions on how I can lower this thing in? I could make a connection at the top of the keel but what about the bottom?

Suggestions welcome.

She goes back in Sunday come hell or highwater!
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Paul Trotter
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Postby Leerac » Sun Aug 23, 2009 7:38 pm

Looks good Admiral, bloody fast , I'm getting worried !
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Postby peter connor » Mon Aug 24, 2009 9:39 am

Paul

Getting the keel back in will be a breeze compared to getting it out.

Use clamps to the aft edge. Secure them so they won't slip under the load of the keel.

Manhandle these with a couple of guys. I did it by myself with a 3/4 inch plate.

Get a couple of hydraulic jacks and extend them as much as possible with timber props up into the underside of the keel case to take the load of the keel when it is lowered and before the clamps rest on top of the keel case. Alternatively use clamps at diffrent postions on the keel and rest them on the keel case and prgressively lower the keel by relocating the clamps.

When the keel rests on the timbers, lower the jacks back toward the floor of the garage etc.

Bingo its in.

I have previously posted photos on this, you just have to look for them.

See Keel Removal - Technical Section

Regards

Peter Connor
C18/370
The Smooth

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paul trotter
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G Clamps

Postby paul trotter » Mon Aug 24, 2009 5:37 pm

Peter,

I must admit the simplicity of using the G clamps is very attractive but I'm worried about two things:

1. Damaging my nice new handiwork
2. Droping it and hurting someone or something

On the first point if I used some ply packers and used about four clamps with three or four guys I could distribute the load better and avoid crushing the ply. As its near the trailing edge I would be compressing less than 1mm of ply and the epoxy. Shoud I really be worried?

On the second point this comes back to how tight the clamps are and how gingerly we do the manoevering?

I have two big boys and one medium boy (thats me). Should I just man handle her in on clamps and be done with it?

Your nervous Nelly
Paul Trotter
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Postby jamesw » Mon Aug 24, 2009 8:24 pm

pm Michael James (mjames) he's done this and if my failing (post 50yo) memory serves me right he used straps, thin enough to fit between the blade and the case but enough to lift - think about seat belt strapping.

just a thought from someone who's not been able to bring himself to do this sort of heroic thing.
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Postby peter connor » Tue Aug 25, 2009 9:42 am

Paul

You can use the straps to get the keel located over the slot and lower enough into the slot to a point where you think the straps might start to jamb.

Don't forget at the front, or top you have the cable plate area which will not have been thickened so there should be plenty of space around it and clamping and or strapping should not be a problem.

If you feed the propping timbers up through the bottom of the slot on jacks you can use a few jacks to alternatively lower the keel whilst stablizing the toppling motion by bracing using the clamp at the front.

If you cannot remove the timber props becuase the trailer rollers get in the way, be prepared to cut them as they stick out of the bottom of the boat.

If none of this makes sense send me a pm and I will give you my home number as a phone call may shed more light than trying to type a response.

PS if you look at my post re keel removal in techical section you will see on the last page the reinstallation of the keel and the use of a clamp at the front end of the keel.

Regards

Peter Connor
C18/370
The Smooth

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Postby maxm » Tue Aug 25, 2009 12:28 pm

jamesw wrote:pm Michael James (mjames) he's done this and if my failing (post 50yo) memory serves me right he used straps, thin enough to fit between the blade and the case but enough to lift - think about seat belt strapping.

just a thought from someone who's not been able to bring himself to do this sort of heroic thing.


I think Verne's method involves the ubiquitous blue packing straps, a length of galvanised pipe and a couple of hefty blokes.
Max
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Mitsubishi PC Challenger auto

"It could easily be accomplished viz a coppuder"
(Dr Strangelove)

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paul trotter
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Knocked off early

Postby paul trotter » Tue Aug 25, 2009 6:42 pm

D Day is getting closer so I knocked off at about 3:30pm today and headed for the boat.

I did a final major sand over all the glassing which looks pretty good. On one side the epoxy is still a little soft and didn't like too much sanding. I mixed up another batch, included some thinners and then trowelled on. I hope this finishing layer will help with the overall curing and the thinners may help in this approach.

So its just one more finishing coat on Thursday. A final light sand on Saturday morning and then she goes in Saturday lunch time and I consume with father and brothers a mini keg of Heineken!!

Almost there!!!!!
Paul Trotter
Nellie C18/472
Vice Commodore North CCYA


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