Topic : Removing Centreboard Case ??

I have a "Hooligan" Merlin no 2969. It ships a lot of water when in use. Inspection shows that the sides of the centre board casing are coming away at the front of the centre board case, there is a lot of staining aroud the centreboard bolt hole and the front of the centre board case and under the mast foot. I am thinking of replacing the centre board casing. How do I obtain more information on the design of the MR and how I might go about this job ? I am intending to use the existing centreboard case as a template for a new one.

Posted: 21/10/2007 22:43:19
By: Adam Kirkwood
I'd leave it to dry for a couple of weeks then have another look. these things tend to look much better when they are dry and it will hopefully just need reglueing.

Any of the class builders (Lawrie Smart, Alan Jackson) will be able to offer advice, but that is a major job and you may be better off getting another boat. Unlike GP14s and Enterprises the Merlin case is not designed to be removed. it also sounds as if the hog, garboards and keel have parted company under the mast - possibly due to too much rig tension - which again will hopefully just need to be glued up, but if the wodd has rotted it's pretty terminal.

Good luck!

Posted: 22/10/2007 08:27:43
By: Chris M
I had this trouble with 1620 15 years ago. Trying to glue in-situ is only a patch-up; if you want to save the boat, then bite the bullet. Remove thwart. I removed the keel bit by bit with chisel & mallet,- taking care not to attack the hog!,- revealing the heads of the screws which fixed C'board case to hog; In my case these were plain steel screws, which had rotted away in the aft part. With all those removed the case came away cleanly without too much difficulty. Clean up Hog, which involved some repair. A tendency is for the hog to split, so a reinforcing piece with the grain across the boat just in front of the case helps. For my repair I rabbetted in the case, this time will s/s screws, and found a nice bit of Honduras mahogany for the keel. I didn't have need but hand tools. 1620 has been sailed all over the place since then, and is in fine shape. Good luck!

Posted: 22/10/2007 12:58:52
By: Rod & Jo
1620 will be very differant to a 29xx boat. On 1620 it may well have been designed to be removed, hence the screws. 1620 will have a solid mahagany case, 29xx won't.

Posted: 22/10/2007 19:52:17
By: Chris M
Correct, solid mahogany.

Posted: 23/10/2007 09:10:29
By: Rod & Jo
Can you clarify the what you meen by the hog & keel. Is the hog the "L" shaped section that forms the front of the centreboard case and extends to go under the mast foot ? Is the keel the main section at the bottom of the boat that runs from the bow to the bottom of the transom ?.

Posted: 23/10/2007 16:54:35
By: Adam Kirkwood
Thats right and the garboards are the bottom planks.

Posted: 23/10/2007 17:48:37
By: Chris
Hi Adam
The hog is on the inside and the keel is on the outside.
I have recently removed a solid mahogany casing from a mk 12. The wood was sound but the 6 main components were becoming seriously unglued from each other and the boat. I have lots of pics and you can email me. There are lots of pitfalls and you will need to know how to overcome a variety of unforseen problems. This is not a quick job and you will need a variety of skills. For example, there were about 24, 30mm no.12 brass screws to remove. Just getting to them was a trial. All were very corroded and c'bored about 15mm deep. I considered myself very lucky to have only 3 that could not be removed. They then had to be dealt with separately when tyring to remove the case! Are you up for all this?

Posted: 23/10/2007 18:02:57
By: Ben 2529
I agree it's not quick, and that you need skills. Time is a great healer; I guess I've forgotten all the hard bits.

Posted: 24/10/2007 11:32:26
By: Rod & Jo
Thanks for the advice. I do not expect this to be easy hence my request for advice, I built a Mirror dinghy when I was 14 and I now run a Kitchen installation business so I have above average tools and woodworking skills (he says modestly !!!). I would be interested in any pictures and accounts of similar work other people have undertaken. For example I am hoping I can remove the paint from the keel and find the screws holding the centreboard case in place (OK I don't expect it will be this straight forward !!!).

I hope to go down to the sailing club in the next few days and take some photos to make the problem clearer.

Posted: 24/10/2007 20:06:22
By: Adam Kirkwood
There won't be screws on your boat, the case will just be glued in. Screws were only used on boats with heavy, solid mahogany case sides. By the time your was built they were using plywood becasue it's lighter.

Posted: 24/10/2007 20:59:28
By: Chris M
I have to say that there may or may not be screws in your boat it will depend if it has had any repair work at all previously. 
3190 split planks from her hog and the case had issues.
Since the repair we have played for two races in survival conditions at Bartley and had several races at our home club plus visits to the Inlands and Midland mug where the wind was zero to a slack leeward shroud.
So far all is well, there was no rot in the timbers just failing 28 year old glue.
Good luck with the task.

Posted: 24/10/2007 22:19:00
By: 3190
I have added some pictures of the problem at:

Use the slide show option to see the best detail

Posted: 25/10/2007 17:14:37
By: Adam Kirkwood

My advice is: remove the centreboard and deposit boat in a garage or other dry place. Leave it for about 3 weeks. By this time it should be dry or almost dry and it will be possible to examine the state of the wood.

If it's not rotten you should be OK to reglue as i'm sure you know. If the plywood is rotten a repair may make sense if you're up for it, but if any of the solid wood ie the keel or hog have rotted it's an absolutely mammoth task.

It looks to me as if the paint or varnish may have worn off the inside of the case which is why the stain goes up so high. The cracks in the front of the case, if the only source of the leak, are just glue failure and should go back togther fine.

You need to get it dry before you make any decisions.

Posted: 25/10/2007 17:24:03
By: Chris M
The wood all appears to be hard. Would it be best if the varnish over the dark area was stripped off and to allow it to dryout and then reglue and revarnish ?

Posted: 26/10/2007 08:22:53
By: Adam Kirkwood
yes. make sure the inside of the case has varnish on it too, this is what often gets neglected on old boats and may not have been done since new!

Also it will probably rot from the inside out. Carefully check the bits behind the mount for the bolt as these go first. Check underneath the boat under the mast for cracks along the keel. The ply will usually rot long before any of the solid wood so if all the ply is sound the rest should be too.

Just make sure its thoroughly dry before you reglue it.

Posted: 26/10/2007 10:15:58
By: Chris M
I agree with Chris. It looks as if the two glued joints fixing the ply to the C'board extention/mast foor have failed totaly. You will need to get them very dry, stripping off external varnish will not hurt. If you're lucky, the wood will be solid enough, but you do need to scrape as much as possible of the dirt etc. out; get a knife down there and open the joint up a bit to wiggle everything out.

Make sure your chosen glue goes deep in, and G cramp eveything firmly up, some screws probably wouldn't hurt. I know people swear by epoxy, but IMHO it risks being too hard for weak and damaged wood/ply; I would use polyeurethane glue on a job like this, it foams well and penetrates all spaces, and even works better if there is a little remaining damp. Good luck!

Posted: 26/10/2007 10:22:27
By: Rod & Jo
I wouldn't use anything other than epoxy, or possibly cascamite as a last resort, on a job like that. It shouldn't flex or move once glued up, and it's failed i would think not due to movement but either frost damage (water freezing and expanding popping the join - it may take a season's use to fail completely) or plain old age.

Epoxy will penetrate and strengthen any slightly soft or dodgy wood as well as glueing it all back together.

Cascamite will tolerate a little damp so would be worth using if you can't guarantee dryness, but it won't strengthen dodgy timer.

You can use screws but i've found they can be a new source of water ingress so wouldn't bother. Just clamping will be fine.

Posted: 26/10/2007 10:33:36
By: Chris M
I find the world much enriched by complementary, and competing, advice!

Posted: 26/10/2007 10:35:51
By: Rod & Jo
There are loads of ways of fixing it. Epoxy is hard and can be brittle, but not as hard and brittle as the stuff that it was built with and on that basis i wouldn't worry about that property.

The property that is important here is the penetration of iffy timber.

Posted: 26/10/2007 11:10:39
By: Chris M
The stain line in the pictures looks as though the boat was left bows down and full of water to the line of the stain,(In which case the varnish probably needs taking back to the bare wood - lots of product or chemicals that will get the stain out.-)  you may be lucky rot wise the ply doesn't seem to have de-laminated if you warm it all up (Her hair dryer!) prior to re glueing with epoxy or your "stuff" of choice it will of course set quicker but temporarily be more fluid too so may well penetrate more - certainly not less - if you put screws in with some epoxy (must be epoxy) and then smear a bit of the inevitable excess over the top you will habe no ingress of water (you may not get them out agian either!) UNLESS you smear the screws with vasaline or liquid detergent first. - Top Tip.

Posted: 26/10/2007 11:31:32
By: Artful Bodger
A bit of history if I can remember the right number.  This boat was built by Aln Boatyard up on the River Amble north of Newcastle.  His boats were built very solidly and did not have the rebated keel that was used (slighlty unsuccessfully) on some boats of that era.  It was owned by Ian Dawson and sailed at Leigh and with me as a crew at Hollingworth Lake.  I think Ian now sails an X332 out of the River Hamble (This time near Southampton).   Such a shame to see a boat suffer damage because somebody did not store it properly.

Best of luck with the task. If you decide the task will not be worthwhile, drop me a line as I know where one of my old boats is (A Disguys) that has not been sailed for a number of years. It did not look in bad condition last time I saw it and the owner seems to have lost all interest in it.

Posted: 26/10/2007 21:20:01
By: Martin Watts


To Reply, please join/renew membership.

Owners Association

Developed & Supported by YorkSoft Ltd


Merlin Rocket Owners Association