4mm plywood - 3 or 5 ply?

jlparsons · Post by **jlparsons** » Thu Sep 11, 2008 4:31 pm

What do you think folks? What have people used? I've looked around while pricing up and 5 is distinctly more expensive than 3, like twice the price. My gut feeling is that, given the majority of the strength is in the glass on the inside and outside, this won't make much difference...

Post by **jem** » Thu Sep 11, 2008 4:35 pm

you found 4mm in 5 ply? Where?

jlparsons · Post by **jlparsons** » Sat Sep 13, 2008 3:35 am

ROBBINS SUPER-ELITE BS1088
High Quality Veneers – multi laminate Mahogany throughout for durability and stability.
Used and approved by the RNLI in high risk marine applications.
4mm 2500 x 1220 5 ply £22.09 £42.18 £80.36
6mm 2500 x 1220 5 ply £26.93 £51.87 £99.73
9mm 2500 x 1220 7 ply £30.87 £59.73 £115.46
12mm 2500 x 1220 7 ply £38.36 £74.73 £145.43
15mm 2500 x 1220 9 ply £44.81 £87.61 £171.22
18mm 2500 x 1220 11 ply £53.11 £104.22 £204.43
25mm 2500 x 1220 13 ply £73.90 £145.79 £287.58

The three prices per type are for quarter, half and full sheets.

As you see - devilishly expensive!!

http://www.robbins.co.uk/mar_plywood.htm[/url]

This is the site, there are cheaper ones on there too. I've never used them yet.

Post by **jem** » Sat Sep 13, 2008 7:54 am

All the 4mm I've seen is 3 ply. 5 ply should be very strong. I wonder if would be stiffer and more difficult to bend?

jlparsons · Post by **jlparsons** » Sat Sep 13, 2008 8:50 am

My gut feeling says it should be more difficult to bend, but it's still on 4mm so I'm sure it'd be possible. But that's a whole lot of dollar for a boat built of that stuff...

I think the fact that you've never used it answers my question - 3 ply will do fine for me!

Post by **jem** » Sat Sep 13, 2008 9:46 am

Long as the plies are of relative even thickness, 3 should be plenty strong.