Attaching internal furniture to GRP hull

Ric said:
I had that question too. Also, how do you cut the furniture to match the contour of the hull? Did you make a cardboard template first?
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A lot people seem to make cardboard templates, I struggle to find cardboard so I usually don't.

The best method is probably a tick stick, google it, there are far better guides than I could write.
I've also used a piece of stiff wire to approximate the curve, sat the wood up against the hull and then used a compass and pencil to transfer the exact contour.
 
Ceirwan said:
A lot people seem to make cardboard templates, I struggle to find cardboard so I usually don't.

The best method is probably a tick stick, google it, there are far better guides than I could write.
I've also used a piece of stiff wire to approximate the curve, sat the wood up against the hull and then used a compass and pencil to transfer the exact contour.
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Tick stick brings up a range of products for removing blood sucking pests!

I create a basic template out of any scrap material. It can be plywood or cardboard but it only has to conform roughly to the curve. Often you can get away with just 2 bits of wood tacked together in a wide V shape. You then take a small square block of wood just large enough to span any gaps between the template and the hull, maybe 10cm. Then simply place it at various points along the hull and trace round it with a pencil onto the template. You should end up with a series of half squares drawn onto your template which, when you reverse the process onto the actual board being used in the build will give you a perfect guide to cut. Just palce the template over the board, put the square block over its traced outlines one at a time and put a dot on the board at each of the two opposite corners of the square block (the ones that would have been in contact with the hull). Then join up the dots, use a bendy stick as a fairing line if you need to but the 'resolution' is normally good enough on a shallow curve like a hull.

You can do the same thing with a compass and pencil by tracing a curve on the template with the point of the compass held against the hull. When you transfer the template to the board to be cut then you trace 2 curves with the compass from the opposite ends of the template curve. Where they intersect is where the point of the compass was against the hull. I find I never have a compass to hand and you really need a locking compass otherwise you will change the radius by accident.
 
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Do not use mitres. Not only are they sharp and thus dangerous the veneer will be featheredged and easy to damage. Any dampness will cause the ply to expand and thus open the mouth of the mitre.

You will be surprised at how little the combined length of your joints will be.

Best and easiest method for exposed external right angle is to use say 45mm square hardwood, rebated on two adjacent sides 20mm by thickness of plywood, with in between corner rounded off.

Then glue and screw plywood from the back. Use good screws and accurate pilot holes so that there is good compression on the joints. Then plenty of varnish all over to seal out dampness.

Internal angles can be just screwed to battens.

Biscuits are great for setting up and for holding on trims but really not strong enough on their own for seats on a boat that will need to flex with the hull without splitting.

I would make the entire from ordinary ply and 2x2 battens first to ensure it fits / works...and then use this assembly as cutting templates.

Take the original fittings out carefully so that you can reuse the materials or so that you can refit..
 
I always scribe to fit exactly, which I done this year to make a bulkhead, it's easy enough, I cut a near enough shape using, thin hardboard, then secure it in position,hasn't got to be perfect, just make sure your largest gap between template and permanent structure is no more than 20mm or less, then cut a pencil down to 25mm, with one hand holding the piece of pencil against the structure, slide it down the template as it follows the shape,at the same time hold a pencil in the other hand against the end of the cut pencil marking out the shape on to the template. You will get a perfect fit.
 
Binman said:
I always scribe to fit exactly, which I done this year to make a bulkhead, it's easy enough, I cut a near enough shape using, thin hardboard, then secure it in position,hasn't got to be perfect, just make sure your largest gap between template and permanent structure is no more than 20mm or less, then cut a pencil down to 25mm, with one hand holding the piece of pencil against the structure, slide it down the template as it follows the shape,at the same time hold a pencil in the other hand against the end of the cut pencil marking out the shape on to the template. You will get a perfect fit.
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Well, you don't get a perfect fit that way as you also have to reverse the process to transcribe the line onto the final board for construction. You can't simply use the template as it will represent a shape with a curve of hull radius minus 25mm (plus half a pencil thickness). The error is often small enough not to worry about especially if you measure out the other dimensions once the curve is fitted but it is an error. Your difficulty will also be to keep the pencil exactly perpendicular to the hull which is why I advise a square block.
 
To fit a holding tank, I had to move a small calorifier from being mounted from two sturdy

stringers, to be mounted on 20mm marine ply, approx. 400x400mm that I first sweated to

the shape of the inside of the boat, then when dried I stuck it to the inside of the hull with

a 3M adhesive. It hasn't fallen off .... yet!..... or changed the shape of the hull.

Mind you, the hull thickness of a Tradewind near the keel, is hardly lightweight in construction. :)

S.
 
If your into refitting big time I suggest a sheet of 4mm ex ply cut into25 mm stripps and either a glue gun and or a stapler. Makes for perfect templates of most stuff.
 
Wansworth said:
If your into refitting big time I suggest a sheet of 4mm ex ply cut into25 mm stripps and either a glue gun and or a stapler. Makes for perfect templates of most stuff.
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So, you keep them pressed to the hull side and gradually build up more thickness or what?

Are you in Galicia, or just the boat? My boat is winterised in Bouzas, just west of Vigo.

S.
 
Scotty_Tradewind said:
So, you keep them pressed to the hull side and gradually build up more thickness or what?

Are you in Galicia, or just the boat? My boat is winterised in Bouzas, just west of Vigo.

S.
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Err no ...For instance if you need a bulkhead ,set up a vertical then the top and bottom and add a few verticals and horizontals as required easier done than said.......

Yes your boat is in the little ya4d with a slipway, name beats me at the moment...... I live in Galicia but my wife comes from Cangas
 
Wansworth said:
Yes your boat is in the little ya4d with a slipway, name beats me at the moment...... I live in Galicia but my wife comes from Cangas
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Drift.........
Forgive me if we've spoken b4, old age/grey cells etc...
The yard Astilleros Lagos, is owned long term by the Lagos family, now run by the two sons.
Father is highly respected in the sailing world and was praised by the King in The Real Yacht Baiona this summer. He is an honorary member of the OCC http://www.coastalboating.net/News/2015/03-2015/31-03-HonoraryMembers/index.html

S.
 
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