Dry dock for resealing windows

[Philip]

Would anyone happen to know of any dry docks in the North West/Midlands area that would allow a Norman GPR boat in? I'm thinking about having the windows taken out and resealed, but really need the boat to be undercover throughout. Chester or Worsley any good?

 

Also any idea about the rough cost both for booking dry dock and a resealing job?

Edited November 9, 2019 by Philip

[Jim Riley]

Doesn't the one in Wigan have a roof? 

[Philip]

2 minutes ago, Jim Riley said:

Doesn't the one in Wigan have a roof? 

Wigan's a lot further from where my boat is moored.

[ditchcrawler]

You dont need a dry dock, just a covered one

 

[Jen-in-Wellies]

What @ditchcrawler said. The "dry" in dry dock is the water being removed so the boat sits on a cradle to allow work on the bits of the hull that are usually wet. Some have a roof, some are open to the sky. Having your boat in a dry dock could make working on the windows harder as they may only be reachable up a step ladder. You would be better with a covered wet dock, Often the sort of thing used for painting.

 

Jen

 

My boat in a covered dry dock, showing how relatively inaccessible the windows become.

Edited November 9, 2019 by Jen-in-Wellies

[Philip]

Fair do's, a covered one it is then. Would anyone know any covered docks in and around the Shropshire Union canal?

[alan_fincher]

2 minutes ago, Philip said:

Fair do's, a covered one it is then. Would anyone know any covered docks in and around the Shropshire Union canal?

Also called a "wet dock".  Norbury Wharf seem to have one, for example.

[David Mack]

For a GRP cruiser it might be as cheap to have the boat craned out and placed on land and placed either in a plastic tent type structure or in a building. Does not necessarily need to be canalside.

[Philip]

Thank you. I'm looking to get the hull surveyed first before spending money elsewhere, the main thing is the wood which basically holds the mould together...if this is sodden/rotten in places then probably not worth spending money as the expansion of the wood will eventually crack and hole the fibreglass. This happened in an area around the saildrive shaft one night last year and was lucky I was onboard at the time as the boat would have been down within a few hours without constant bilge pumping until out of the water.

Edited November 11, 2019 by Philip

[Tony Brooks]

52 minutes ago, Philip said:

Thank you. I'm looking to get the hull surveyed first before spending money elsewhere, the main thing is the wood which basically holds the mould together...if this is sodden/rotten in places then probably not worth spending money as the expansion of the wood will eventually crack and hole the fibreglass. This happened in an area around the saildrive shaft one night last year and was lucky I was onboard at the time as the boat would have been down within a few hours without constant bilge pumping until out of the water.

 

I don't understand this post. I can see no way wood would be used to hold the various parts of the hull and superstructure together  - a mould is what those parts came out of. Wood may be used as protection or a trim where the parts join but that actual join is usually bonded  an/or bolted.

 

There may be paper rope,  balsa wood, or some other "filling" inside the GRP ribs that are part of the hull but the paper/wood is only a former for the GRP to be laid over.

 

I know little about the detail of Norman construction but I do not believe that there is any wood in the hull laminations making the hull in effect and inner and outer layer with wood between but where there is likely to be compression or extra forces on the underwater hull cause by fittings there may be an area of wood glassed down onto the hull to spread the load. I would not be surprised if this was not done to mount a saildrive but that would be rather vulnerable Some larger GRP to grounding and exerting a large leverage on the mounting points. That could split the inner glass layer holding the reinforcing timber in place but not the hull itself. I would question the wisdom of a saildrive on a canal boat. In fact I suspect insufficient care was taken to ensure the timber pad was protected from water ingress where the large hole was cut to allow the saildrive to drop through the hull. So that problem may well be down to faulty workmanship

 

In short I think that you may have misunderstood the details of the hull construction and that you think there is wood when there is not. I have never fund wood encapsulated at the joints between hull, inner moulding and cabin top on any GRP boat I have seen. There is almost universally a wooden or "rubber" rubbing band covering the joint on the outside of the hull but this is not structural. 

 

PS - I very much doubt there is any wood in the window area. It is usually just a single GRP skin that the windows are bolted/screwed to. There may be a wooden trim on the inside.

Edited November 11, 2019 by Tony Brooks

[mrsmelly]

Get under a motorway or dual carriageway bridge somewhere.

[Philip]

9 minutes ago, Tony Brooks said:

 

I don't understand this post. I can see no way wood would be used to hold the various parts of the hull and superstructure together  - a mould is what those parts came out of. Wood may be used as protection or a trim where the parts join but that actual join is usually bonded  an/or bolted.

 

There may be paper rope,  balsa wood, or some other "filling" inside the GRP ribs that are part of the hull but the paper/wood is only a former for the GRP to be laid over.

 

I know little about the detail of Norman construction but I do not believe that there is any wood in the hull laminations making the hull in effect and inner and outer layer with wood between but where there is likely to be compression or extra forces on the underwater hull cause by fittings there may be an area of wood glassed down onto the hull to spread the load. I would not be surprised if this was not done to mount a saildrive but that would be rather vulnerable Some larger GRP to grounding and exerting a large leverage on the mounting points. That could split the inner glass layer holding the reinforcing timber in place but not the hull itself. I would question the wisdom of a saildrive on a canal boat. In fact I suspect insufficient care was taken to ensure the timber pad was protected from water ingress where the large hole was cut to allow the saildrive to drop through the hull. So that problem may well be down to faulty workmanship

 

In short I think that you may have misunderstood the details of the hull construction and that you think there is wood when there is not. I have never fund wood encapsulated at the joints between hull, inner moulding and cabin top on any GRP boat I have seen. There is almost universally a wooden or "rubber" rubbing band covering the joint on the outside of the hull but this is not structural. 

I have to say I know little about the hull structure, but assumed the whole mould was a layer of wood surrounded either side by the GRP, as is the case for the saildrive shaft. What you have described re the saildrive hole and the cause of the problem is what happened.

[Tony Brooks]

I hope that I have reassured you in respect of the window area. If you take one window out I am 99% certain all you will see is the edge of the GRP moulding, perhaps 4 to 6mm thick and the edge of the internal trim fabric. You may ask why not 100% sure and the answer is there is always something new to find out and I have never had much to do with Normans so I can't be absolutely sure. but general GRP boat construction practice suggest I am not wrong.

 

If there is a significant return around the inside of the window then there might be a layer of closed cell foam insulation moulded between two GRP layers but I have ever come across that.

[Alan de Enfield]

Many smaller GRP boats are built with a hard foam or balsawood core around which the fibreglass is moulded, this gives a rigidity but little additional weight.

 

As Tony says - you will find that if you remove the windows there will be 'just fibreglass' showing as the core is sandwiched in between the fibreglass and at the 'edges' the fibreglass is moulded all around the core (like jam in a do-nut).

 

It would be usual for the windows to be actually held in with U-shaped rubber mouldings (like a car windscreen), are yours not like this ?

 

 

http://www.normanboats.co.uk/Fixit page.htm

 

 

There are instructions for window replacement on the Norman Boats website (scroll about half way down until you get to this - then there are pictures)

 

Re-building Norman aluminium framed windows.

(Thanks again Simon)

Mk.3 Norman 23’s have aluminium framed windows made from extruded ‘h’ section with mitred corners. The corners are held together with fitted steel angle pieces screwed to the aluminium with steel screws. The glass is sealed into the frame with rubber ‘u’ section. If the glass or sealing section needs replacing the whole frame needs to be dismantled to put the new materials in. If the sealant is leaking the steel will be in a particularly bad way, the screws will probably rusted solid and will need to be drilled out.

Take out the window, you can save the brass countersunk screws or replace with stainless steel, they are 2ba but you could use 5mm. Before carrying out any dismantling, get a large piece of paper or card and draw around the whole window and mark the aluminium frame sections to identify them later. I used [PTL], meaning [P]ort side window, [T]op [L]eft, etc, marking each end of the 4 pieces of frame. Use a permanent marker on the inside face of the bit that bolts against the boat. On the inside of the boat there is a 4 piece ali frame for the nuts to tighten up against. As you remove them, mark these also for future identification. The 4 pieces are unique so you wouldn’t be able to get them in the wrong place, but it does make life easier.

Clean everything up, throw away the window seals, steel screws and angle pieces, they are probably all useless anyway. I made new angle pieces from steel plate, but should have used ali or brass to make a rust-proof job. I used new brass 2ba countersunk screws to fix the angles to the frames. Cut strips of plate about 4” long so they are a nice fit in the window slot. Mark the middle and bend to suit the angle of the corners, check against the card outline drawing you did. Find a piece of flat ply or something you can clamp the frame pieces to. Lay the frame pieces over the card drawing on the ply and clamp 2 pieces down forming a tight corner. Put the angle piece in the slot and mark the position of the screws. Drill and tap screw holes a fraction towards the apex of the angle, not directly where they should be. This makes the frame tighten up as you finally screw everything together. A simple trick to do this, instead of putting the angle directly up against the ali frame, put a strip of thin card in first to make a spacer. Once the 4 corners are done, test tighten it up without the spacers and check against the card outline drawing to see if the new frame is as ‘square’ as it used to be. This ensures that all the frame bolt holes line up. Remove one side and slide the glass back in, you may have to shorten some of the corner angle screws. Find some card, wood or metal strip that is the same thickness of the old sealing ‘u’ section. Put these strips between the frame and the glass. Using black silicone sealer, squeeze in the new sealant and smooth off, much easier than trying to obtain the correct size 'u’ section. Let this go off, turn the window over, remove the spacer strips and apply silicone. When this has gone off, the window is complete. I bought black silicone sealant from the glazier that I bought the new toughened glass from, they use black silicone where they cant fit the rubber trims back in on double glazing. I paid £4 per tube, much cheaper than ‘marine’ silicone!

This shouldn’t be beyond anyone that has basic DIY stills, but does require tools, such as a thread tap, a drill and drill bits, hand saw, bench vice, etc. I am lucky in having an engineering workshop at home, but you may have friends that work in engineering that could help do the workshop bits.

These instructions also apply to the top cockpit windows. All but 2 sections are ‘u’ section ali rather than ‘h’ section. The corners are fixed in the same way.

[Philip]

16 minutes ago, Tony Brooks said:

I hope that I have reassured you in respect of the window area. If you take one window out I am 99% certain all you will see is the edge of the GRP moulding, perhaps 4 to 6mm thick and the edge of the internal trim fabric. You may ask why not 100% sure and the answer is there is always something new to find out and I have never had much to do with Normans so I can't be absolutely sure. but general GRP boat construction practice suggest I am not wrong.

 

If there is a significant return around the inside of the window then there might be a layer of closed cell foam insulation moulded between two GRP layers but I have ever come across that.

As far as I know there is no foam insulation between the layers. All of the windows sit in aluminium frames which are sealed to the GRP.

[rusty69]

5 minutes ago, Alan de Enfield said:

Many smaller GRP boats are built with a hard foam or balsawood core around which the fibreglass is moulded, this gives a rigidity but little additional weight.

Our sailing boat has a balsa cored deck. When we bought it, some of the deck was sagging on the cabin top. There had been some water ingress through a deck fitting, the balsa core had got saturated. We spent a month cutting out the inner skin, epoxying in a new balsa core, re attaching the inner skin a re-bedding all of the deck fittings. Balsa cores are great whilst they remain dry.

 

The windows on our sail boat also now leak. They don't leak through the frame to cabin joint, but the rubber seal between glass and frame.It is a job I have been putting off, with the help of the good Captain Tolley.

 

Oh, the joys of boat ownership.

[Alan de Enfield]

10 minutes ago, rusty69 said:

Our sailing boat has a balsa cored deck. When we bought it, some of the deck was sagging on the cabin top. There had been some water ingress through a deck fitting, the balsa core had got saturated. We spent a month cutting out the inner skin, epoxying in a new balsa core, re attaching the inner skin a re-bedding all of the deck fittings. Balsa cores are great whilst they remain dry.

 

The windows on our sail boat also now leak. They don't leak through the frame to cabin joint, but the rubber seal between glass and frame.It is a job I have been putting off, with the help of the good Captain Tolley.

 

Oh, the joys of boat ownership.

Many years ago I looked at a buying a big Trawler Yacht, it was a beautiful boat built in one of the large Taiwan Shipyards, a proper walk in engine room with 'big Caterpillars' -  but decided against it - walking along the deck was like being on a trampoline - the deck had delaminated from the core and it was going to be a HUGE job to correct it.

[rusty69]

2 minutes ago, Alan de Enfield said:

Many years ago I looked at a buying a big Trawler Yacht, it was a beautiful boat built in one of the large Taiwan Shipyards, a proper walk in engine room with 'big Caterpillars' -  but decided against it - walking along the deck was like being on a trampoline - the deck had delaminated from the core and it was going to be a HUGE job to correct it.

You did the right thing. Walk away fast before you fall in love with it.

 

Still, you got your trampoline eventually. Don't all catamarans have them?

 

The price of our boat reflected the work involved. I was confident I could do the job myself, the materials were cheap,and so was my time.

[Alan de Enfield]

4 minutes ago, rusty69 said:

Still, you got your trampoline eventually. Don't all catamarans have them?

No, not all, but 'Ocean category A' do to avoid being swamped as the waves break over the bow.

 

 

[Mad Harold]

Just replaced the windows on my Norman 20.Alan's post is full of good advice.

A dry dock is not necessary,as when the window frame was removed,I simply taped bin liners over the apertures using duct tape,and that proved water tight for the couple of weeks it took me to replace the windows.

There is wood in the construction.A timber is glassed in on the transom to give support to the outboard,and a section of the transom is double skinned with balsa in between.There are also some supporting timbers glassed in under the fwd deck.

[rusty69]

5 minutes ago, Alan de Enfield said:

No, not all, but 'Ocean category A' do to avoid being swamped as the waves break over the bow.

The Hobie cat I used to go sailing definitely had one,but probably for different reasons.

[Mad Harold]

43 minutes ago, rusty69 said:

Our sailing boat has a balsa cored deck. When we bought it, some of the deck was sagging on the cabin top. There had been some water ingress through a deck fitting, the balsa core had got saturated. We spent a month cutting out the inner skin, epoxying in a new balsa core, re attaching the inner skin a re-bedding all of the deck fittings. Balsa cores are great whilst they remain dry.

 

The windows on our sail boat also now leak. They don't leak through the frame to cabin joint, but the rubber seal between glass and frame.It is a job I have been putting off, with the help of the good Captain Tolley.

 

Oh, the joys of boat ownership.

For windows that leak between the glass and the seal,check that the seal is not covering the drain slots or holes.It may be necessary to cut through the seal with a craft knife if you have slots.If you have drain holes,I don't know.