Attaching internal furniture to GRP hull

[Ric]

My boat (like most AWBs) has a overly large fore-aft orientated table in the saloon which takes up most of the internal space, prevents me from moving around easily, and makes access to undersea lockers difficult. I am therefore planning to rip it out and build a smaller port-starboard orientated table into the port side of the boat, with fore-aft facing seating. I will make the table drop down to create a nice wide bunk, which will also be on a detachable leg so that I can use it in the cockpit (where I eat 99% of the time anyway).

This will involve ripping out the entire port seat and rebuilding it with the starboard edge moved to starboard, and adding transverse walls shaped to the outer hull to create a footwell.

I am wondering what the best way is to attach the new furniture to the outer wall of the hull and to the floor frame. Should I glass the furniture to the inner wall of the hull and to the floor frames? Or would it be better to build the furniture as stand alone units which then are just held with screws to the other furniture (as most of the other furniture is built and attached).

 

[Poignard]

I prefer to fix battens to the hull using thickened epoxy and screw the furniture to them. Then if you need to remove the furniture for any reason, it's easy to do so without damaging it.

 

[vyv_cox]

As Parsifal says, thickened epoxy is the preferred attachment method. Glassing in is messy, difficult to achieve a neat appearance and nowhere near as strong. The battens method is the better one but I epoxied my galley direct to the hull due to lack of space for battens in a small boat.

 

[sailorman]

Any major alterations to an AWB may well detract from its value.

 

[NormanS]

Any major alterations to an AWB may well detract from its value.

Should that prevent the OP from doing alterations which he feels will enhance his enjoyment of his boat?
What a mercenary attitude!

 

[Ric]

As Parsifal says, thickened epoxy is the preferred attachment method. Glassing in is messy, difficult to achieve a neat appearance and nowhere near as strong. The battens method is the better one but I epoxied my galley direct to the hull due to lack of space for battens in a small boat.

Thank you - I will use the batten method. Did you also use battens to fix the furniture to existing furniture? On the advice of a joiner-friend, I was thinking of perhaps purchasing a biscuit-cutter and tagging them in with biscuits, but have no experience with using such a method.

Also, what the best way to butt two pieces together at right-angles and achieve a neat external finish? Again, my professional joiner friend suggested buying a decent disc-saw and cutting the edges at 45 degrees, then butting them together. However, I am not convinced that this will stand up to the rigours of offshore sailing.

 

[Lon nan Gruagach]

Thank you - I will use the batten method. Did you also use battens to fix the furniture to existing furniture? On the advice of a joiner-friend, I was thinking of perhaps purchasing a biscuit-cutter and tagging them in with biscuits, but have no experience with using such a method.

Also, what the best way to butt two pieces together at right-angles and achieve a neat external finish? Again, my professional joiner friend suggested buying a decent disc-saw and cutting the edges at 45 degrees, then butting them together. However, I am not convinced that this will stand up to the rigours of offshore sailing.

Biscuit joints are a walk in the park with a good cutter, you get a very strong machine flush joint, and quick too.
A 45 degree joint will be stronger (bigger surface area for glue) than a square cut butt, again with power tools they come out neat and quick. For an even fancier, stronger joint there are router blades that will give large surface area, good alignment, called a lock mitre bit:

 

[Bobc]

Any major alterations to an AWB may well detract from its value.

Or may enhance it

 

[sailorman]

Should that prevent the OP from doing alterations which he feels will enhance his enjoyment of his boat?
What a mercenary attitude![/QUOTE]
Certainly not, just an observation.

 

[Ric]

Biscuit joints are a walk in the park with a good cutter, you get a very strong machine flush joint, and quick too.
A 45 degree joint will be stronger (bigger surface area for glue) than a square cut butt, again with power tools they come out neat and quick. For an even fancier, stronger joint there are router blades that will give large surface area, good alignment, called a lock mitre bit:

Hmm looks like I might need a router too! Will that method work with teak-faced ply?

 

[Wansworth]

In my Albino Vega according to the videos I have seen its possible to take out the whole of the inside, refurbish and replace, the bulkheads are fixed with bolts to grp flanges glassed to the hull....

 

[Tranona]

Thank you - I will use the batten method. Did you also use battens to fix the furniture to existing furniture? On the advice of a joiner-friend, I was thinking of perhaps purchasing a biscuit-cutter and tagging them in with biscuits, but have no experience with using such a method.

Also, what the best way to butt two pieces together at right-angles and achieve a neat external finish? Again, my professional joiner friend suggested buying a decent disc-saw and cutting the edges at 45 degrees, then butting them together. However, I am not convinced that this will stand up to the rigours of offshore sailing.

Just screw to battens if you want the furniture removable, otherwise glue. You can counterbore and plug any screwheads. For corners the easiest way to get a good neat finish is to use corner mouldings. You can get them in teak to take either 12 or 18mm ply from www.kjhowells.com Lots of teak mouldings from there to help finish panel work off neatly without being a joiner!

 

[doug748]

Thank you - I will use the batten method. Did you also use battens to fix the furniture to existing furniture? On the advice of a joiner-friend, I was thinking of perhaps purchasing a biscuit-cutter and tagging them in with biscuits, but have no experience with using such a method.

Also, what the best way to butt two pieces together at right-angles and achieve a neat external finish? Again, my professional joiner friend suggested buying a decent disc-saw and cutting the edges at 45 degrees, then butting them together. However, I am not convinced that this will stand up to the rigours of offshore sailing.

As Dougal T has suggested a biscuit joint is very easy to make if you have the kit. The originals were crunchingly expensive but the alternatives have come down a lot. I bought the Lidl/Aldi version for about 25 quid and found it a perfectly usable tool.

I would follow the advice to make mitre joints, for neatness, unless there was a reason not to. They can be dangerously sharp on the outside so you might wish to lip the board, with solid timber, on the exposed edge and do a 90deg biscuit joint instead; that way you can have a heavy radius on the corner. It may not look so neat though, getting a good match is the key. Rassy, et al, would joint the two panels into a solid sguare of timber and round it very heavily which is more work, expense and has increased risk of nicking the vulnerable veneered panel as you work.
An alternative is to make, and glue up your mitre joint and then cut out the corner with a router and inlay a solid stringing of small solid stuff say 3mm square. As I write I am thinking I would experiment with this first to check how flaky the board is. It is possible to put biscuits in the mitre if you want to.

Modern boards are very fragile and splintering out the grain is a problem, for that reason I might see if I could find someone with a heavy table saw and sharp blade, to cut the mitres. Tape the cut line before machining.

 

[prv]

Hmm looks like I might need a router too!

Having made various bits of interior joinery for two boats now, I would regard a router as pretty much essential.

Pete

 

[TQA]

Have a look here http://www.westsystem.com/ss/use-guides/

 

[Ceirwan]

I've always used the method of cutting the furniture to match the contour of the hull and then filleting with epoxy followed by a few layers of glass tape. But I've used that method purely because I didn't know of any other.

When using battens glued or epoxied to the hull do you build up the the batten over multiple layers (in order that the material is thin enough to conform to the hull shape) until its thick enough, or do you just epoxy in small blocks of wood and screw the furniture to those?

 

[Sybarite]

My boat (like most AWBs) has a overly large fore-aft orientated table in the saloon which takes up most of the internal space, prevents me from moving around easily, and makes access to undersea lockers difficult. I am therefore planning to rip it out and build a smaller port-starboard orientated table into the port side of the boat, with fore-aft facing seating. I will make the table drop down to create a nice wide bunk, which will also be on a detachable leg so that I can use it in the cockpit (where I eat 99% of the time anyway).

This will involve ripping out the entire port seat and rebuilding it with the starboard edge moved to starboard, and adding transverse walls shaped to the outer hull to create a footwell.

I am wondering what the best way is to attach the new furniture to the outer wall of the hull and to the floor frame. Should I glass the furniture to the inner wall of the hull and to the floor frames? Or would it be better to build the furniture as stand alone units which then are just held with screws to the other furniture (as most of the other furniture is built and attached).

You may find what you are looking for in the thread " Complete boat renovation project". It's in French but very well illustrated.

 

[Wansworth]

Looks thougher series....... didn't the pho do something along the same lines...... shame I cannot read French........I have a an excellent French magazine all about restoring a house again excellent stuff..........

 

[Ric]

I've always used the method of cutting the furniture to match the contour of the hull and then filleting with epoxy followed by a few layers of glass tape. But I've used that method purely because I didn't know of any other.

When using battens glued or epoxied to the hull do you build up the the batten over multiple layers (in order that the material is thin enough to conform to the hull shape) until its thick enough, or do you just epoxy in small blocks of wood and screw the furniture to those?

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?

 

[Ric]

You may find what you are looking for in the thread " Complete boat renovation project". It's in French but very well illustrated.

Do you have a link to that - or the name of the book in French? I have lived in France for fifteen years so no problem with the language.