Mirror Dinghy Restoration

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Shades
Posts: 3
Joined: Mon Aug 01, 2011 11:41 am

Mirror Dinghy Restoration

Post by Shades »

I have got a 1981 Mirror that I want to get back into working order. It transpires it was a race winning boat from N Ireland called 'Mr Rusty'. It's well built (and light) but has suffered some damage, most likely from not being secured to its trailer properly. There are 2 splits in the cockpit floor (see photos) from where it has bounced on the trailer. There is also a 1" wedge shaped hole up near the bow. I'd quite like to do a decent job on the boat but seeing it will be used for pottering, teaching and perhaps the odd club race, I don't want to spend a fortune and would rather put money towards fittings etc. I could replace the panels but think that could be a bit 'over the top' and may push my skills and time somewhat. My thought with the bow was to secure a piece of plywood behind the hole and fill from the outside. The holes in the cockpit floor I'm not so sure about. My thought was to run a piece of ply on the port side (centre line to buoyancy tank) covering the hole and match it on the stbd side so it doesn't look 'odd'. I'd fill from the underside. The idea of the additional ply would be to stiffen the cockpit floor round the split. I'd fashion a similar backing piece for the stbd side split and 'mirror' it on the port side. The other option would be to open the splits up a bit, fill with glass fibre and sand back flush. My concern here is that the cockpit floor won't be strong enough and would crack again once someone is walking around on it. I was involved with 3 wooden boat refits as a teenager but my skills are a little rusty after moving into the world of glassfibre boats.

Any advice would be useful...as well as any recommendations for types of filler glue etc? One advantage of the boat is that it's been stored inside for the past few years and is really 'bone dry'.

Once I get the holes sorted I'm going to get rid of the old paint and give it a new paint job all over.
Attachments
DSC_0471.jpg
This shows the split on the stbd side of the cockpit floor
(10.39 KiB) Not downloaded yet
DSC_0468.jpg
This shows the split on the port side of the cockpit floor
(10.58 KiB) Not downloaded yet
DSC_0467.jpg
The 2 bits of white newspaper mark the places where the cockpit floor plywood is split.
(11.83 KiB) Not downloaded yet
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PeterV
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Joined: Thu Sep 16, 2004 8:47 pm
Location: Locks Heath, Hampshire

Re: Mirror Dinghy Restoration

Post by PeterV »

Mirror floor panels are very felxible and prone to spiltting. Your proposal to put a patch on the inside is reasonable but will create the problem that you'll have one part of the floor stiffer than the rest, possibly causing fiurther problems. I also think that any attempt to repair with glue, glassfibre or filler will fail. One otion is to insert another floor batten over the split, and replicate this on both sides. Another option I've seen work is to add a complete panel over the floor on the inside.
PeterV
Finn K197 & GBR564
Warsash
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jpa_wfsc
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Joined: Sun Dec 04, 2005 9:52 pm
Location: Oxford (Work) Coteswold Water Park (Sailing)

Re: Mirror Dinghy Restoration

Post by jpa_wfsc »

Hi

your mirror already has some extra stiffening strips on the floor. So adding some more won't cause havoc - just add a little weight which will not bother the use you suggest you plan for her.

Glue using epoxy resin - there are various manufacturer's and you need to carefully follow their instructions. WEST systems are possibly the most popular and easiest to buy (they do 'handipacs' that are great for repair work). Add fillers (microballoons) to get a paste-like glue - which also stretches the resin out somewhat - and makes a good and easy to sand filler for the outside.

And then enjoy sailing!
j./

National 12 "Spider" 2523
Finn K468 'Captain Scarlet'

British Moth, 630, early 60's 'Pisces'

!!!! Not CVRDA !!!!
Comet Trio - something always ready to sail.
Shades
Posts: 3
Joined: Mon Aug 01, 2011 11:41 am

Re: Mirror Dinghy Restoration

Post by Shades »

Thanks for the information.
Sounds like the best option is to run more matching cockpit battens on each side (so it matches) and extend the existing ones. Alternatively, run something athwartships to cover the port aft split (stbd side as well so they match) with some more battens as well. The fact that older Mirrors are prone to cockpit splits is something I picked up from the Trident website as they sell a double bottom kit (£172). Seems a lot but I'd kick myself if I'd worked on the other solutions just to have another split due to the cockpit floor having differing levels of stiffness.

I'm not 100% certain how the double floor is fitted? It comes with tape, glue, screws etc so perhaps implies that you remove the existing cockpit floor battens and secure the double floor over the top? My 'doubting side' asks the question of how you keep the water out from between the 2 floors, unless that's achieved by some serious glueing and taping of the joints. From the web picture, it doesn't look like it runs the full length of the cockpit? Sounds like this could be the low risk option that guarantees success. The cracks can be filled normally as they're not taking any load.

Does anyone have any experience of fitting a double cockpit floor?
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jpa_wfsc
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Location: Oxford (Work) Coteswold Water Park (Sailing)

Re: Mirror Dinghy Restoration

Post by jpa_wfsc »

I think it does run the full length of the floor. They supply new battens, fot rest etc. so one assumes you have to remove the existing ones. That would be hard...

I should definitely go with getting more battens and glueing them on. The next level of repair I would do myself would be to cut out the floor, and make a new one, rather than doubling the floor thickness.
j./

National 12 "Spider" 2523
Finn K468 'Captain Scarlet'

British Moth, 630, early 60's 'Pisces'

!!!! Not CVRDA !!!!
Comet Trio - something always ready to sail.
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jpa_wfsc
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Location: Oxford (Work) Coteswold Water Park (Sailing)

Re: Mirror Dinghy Restoration

Post by jpa_wfsc »

Just noticed that times change. Our complete mirror kit in 1972, (no spinnaker or paint, but _everything_ else_ was £110..... now its £1,700!!
j./

National 12 "Spider" 2523
Finn K468 'Captain Scarlet'

British Moth, 630, early 60's 'Pisces'

!!!! Not CVRDA !!!!
Comet Trio - something always ready to sail.
SoggyBadger
Posts: 282
Joined: Mon Jan 31, 2011 8:39 pm
Location: Staffordshire

Re: Mirror Dinghy Restoration

Post by SoggyBadger »

jpa_wfsc wrote:Just noticed that times change. Our complete mirror kit in 1972, (no spinnaker or paint, but _everything_ else_ was £110..... now its £1,700!!
Beer's no longer 14p a pint either :shock: :D
Best wishes


SB
Shades
Posts: 3
Joined: Mon Aug 01, 2011 11:41 am

Re: Mirror Dinghy Restoration

Post by Shades »

Agree removal of the cockpit floor strips could be difficult and do more harm than good. I've noticed you can buy (or make) a more substantial foot rest than the existing one and looking at photos of Mirrors, a lot of boats have the cockpit strips extending the full length. More opportunities to strengthen the floor. The £172 cost of the double floor seems a little 'out of spirit' with the restoration job and I'd rather put that money towards fittings.
fcdbm
Posts: 36
Joined: Sun Jan 18, 2009 5:51 pm

Re: Mirror Dinghy Restoration

Post by fcdbm »

I have owned Mirrors and Miracle dinghies and spent quite a time sorting out splits in the ply floor. So here are some of my lessons learnt.

The ply used for Mirrors was not always very good, and suffered from voids, between the ends of veneers. Water can get in and weaken the ply.

The floor battens were glued and nailed and can flex and crack away. Water then gets under the battens and in my Miracle this rotted the ply under the battens.

My suggestion would be to go for the double floor. This would involve stripping out the battens, prepping the surface and then gluing on the overply panels. Refix battens, bailer etc.

If you are confident woodworker you can make up a paper template and cut the ply to suit. Using good ply, epoxy and making good paint work will cost about £40 for good marine ply, £25.00 for a kilo of epoxy, plus paint and varnish say £25.00.

Then make good the outer surface where the ply has split.

This will be a good sound repair and well resistant to those of us with less than balletic agility and lightness of foot....
PaulM
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Location: Hampshire

Re: Mirror Dinghy Restoration

Post by PaulM »

Can somebody who owns a Mirror with both mast step positions tell me what the measurement is from the forward (solo) mast step to the daggerboard slot.

Paul M
John Dolan
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Joined: Tue Nov 08, 2011 7:33 pm

Re: Mirror Dinghy Restoration

Post by John Dolan »

PaulM wrote:Can somebody who owns a Mirror with both mast step positions tell me what the measurement is from the forward (solo) mast step to the daggerboard slot.

Paul M
Hi Paul

I had a quick look with a tape measure on our ~1971 boat (25583) as the light faded yesterday
Re-reading your message I realised I've measured slightly different things but hopefully this is useful to you:
The distance from the outside front of the centreboard case to the bulkhead is 182mm.
The distance from the bulkhead to the rear of the rear (normal) mast step is 20mm
The centres of the mast steps are separated by 254mm
I forgot to measure the mast step block itself but this is around 50-60mm square

The forward shroud plates are ~245mm forward of the normal plates.

Do say if you could use more clarification - I can always go back to where she is kept and re-measure

I have heard that Mirrors sailed main-only & with the mast forward are difficult to tack. I discussed this with friends and it probably translates as 'suffers from lee helm', implying the forward mast position as built may actually be too far forward ie the centre of pressure is too far forward relative to the keel, so it might be worth being prepared to experiment with the forward step position in any case

hope this helps
John
Rupert
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Re: Mirror Dinghy Restoration

Post by Rupert »

I've never had any trouble with the forward mast position, even when the kids were toddlers and crawling all over the foredeck.
Rupert
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jpa_wfsc
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Re: Mirror Dinghy Restoration

Post by jpa_wfsc »

The main problem with the forward mast position is that the kicking strap ties down to the cockpit face of the bulkhead. Thus when you sheet out the kicker tensions up--- or when you sheet in it loosens.

I always found the mirror sails OK with just the main up and the mast in the normal position anyhow - but will still be difficult to tack getting stuck head to wind.

Or in other words - I would not bother putting the forward mast step on at all (unless compliance with class rules / desire to be original is important to you).
j./

National 12 "Spider" 2523
Finn K468 'Captain Scarlet'

British Moth, 630, early 60's 'Pisces'

!!!! Not CVRDA !!!!
Comet Trio - something always ready to sail.
Rupert
Posts: 6255
Joined: Thu Sep 16, 2004 8:40 pm
Location: Cotswold Water Park

Re: Mirror Dinghy Restoration

Post by Rupert »

I just tied a loop of rope round the bottom of the halyard cleats and took the kicker off there. Never had head to wind trouble either, but have with the mast in the back position and no jib. Makes a lovely single sailed boat.
Rupert
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