Ceiling panels on my boat were looking a little shabby so I have taken them off and they are 3 ply with what I can only describe as contact or drawer lining material adhered to the underside. The longer panels are 2420 and the maximum width of 740 held up by screwed in teak strips at the edges so no need to screw through the ply.
Can't seem to find a supplier in Sydney or Newcastle for melamine faced 3 ply or even a supplier for a roll of drawer lining material in white of at least 2020 by 750. I can find a supplier in Melbourne but they want 150 bucks delivery.
Bunnings sell 4 mm thick melamine backed by MDF or something which I guess I could use provided I painted the back and edges with epoxy but I would rather use three ply or stick material to my existing 3 ply panels. Anyone got any ideas? Thanks.

Could probably use Laminate (laminex). It has a good hard face, in many colours, and is fairly waterproof. You can also get laminate as used in shower cubicles which is fully waterproof and thicker. I used laminex and it is fine. All sizes available.
Terry

My boat had been lined with the mdf backed material which is totally unsuitable for the marine environment. Even the dress surface absorbed water.

I used the "laminate" or wet area sheeting described above for my galley and head bench tops which gave an excellent result. It is not easy to work and is best cut with a power saw by a cabinet maker or similar to accurate measurements.

Being a glass yacht I saw no need to reline it so I just used a marine grade gloss paint.




The bench tops came up beautiful.

I faced similar challenge as Julesmoto a year ago. Plywood ceiling panels, nicely fitted but dark varnish made the saloon and vee berth very dark.
I tried using white expanded foam sheets from bunnings but the results looked shabby due to difficulty cutting bevel edges. I chose to remove the sheets, give them 3 coats of quick drying primer and two gloss top coats at home. I'm happy, the Admiral fully approves so all good.

Thank you for your helpful (as always) suggestions guys.

So I go into Spotlight this morning and an 18-year-old girl walks up to serve me. I start explaining what I want to do in very simple terms and she says "I'll show you what I helped my dad put on the ceiling of our yacht". The stuff looked spot on but they were out of white which she says they will have next week.
Being impatient I go into Bunnings to look at spray adhesive but get distracted and buy some undercoat and white paint. Came home and undercoated one 2.4 m panel which looks great already. No knots or other imperfections in the 3 ply. Try that with the crap ply that we can buy today! Anyway I will apply the top coat and see how it looks and then decide whether it's paint or vinyl. I guess it will depend upon whether the surface of all the other panels is as good as the one I picked to start on. If I decide vinyl then I may have a problem getting the spray adhesive to stick to the paint but I'm sure I can rough it up.