Marine ply thickness for cantilevered kitchen bench top

[Tom Radtke]

Renovating my kitchen and looking for advice on thoughts/experiences on minimum thickness for a 300mm cantilevered “breakfast bar” style cabinet. I’m thinking 15-18mm quality AA grade marine ply to retain character of the place and just checking RE stiffness/flexion. I’ll be simply oiling it. The cabinet is an older pine panelled, 500mm deep x 2400 long (incl overhang top) bench.

[CaRaZaY]

Ply has a lot of strength but I definitely wouldn't be using 15mm. The 18mm would be okay for a regular countertop but just for additional strength and looks with your cantilever I'd personally use 25mm ply.
The thickness will give it more of a regular benchtop feel, there'll be less likelihood of flex, plus you'll have scope to round off the edges for a nice finish. The thinner boards might start to have a 'blade edge' feel to them for anyone leaning up against it.

You could also speak to your plywood supplier and ask them if they have additional manufacturer info on cantiliever span strength.

[havabeer69]

dunno if i'd use marine ply as a kitchen bench top.

the veneers aren't going to take too much to get through, especially if you sand it every so often. Id consider on of the thicker "project" panels the big green warehouse sells, ton's of thickness of solid wood with no bounce or give to it at all.

[Tom Radtke]

Yeah, thanks and yea , will go 18 maybe even 25 mm., I have a mate coming over tomorrow (carpenter) and he did a solid timber bench in his place recently and so will get his thoughts on ply vs solid. Still like the thought of marine ply… and a couple of coats of Tung oil

[oldwoodie]

I bought some vic ash panels from the big green store for bench-tops. 33mm excellent stuff.
Cheaper than 25mm marine ply

[Tom Radtke]

Thanks for that, I’ll have a look. What did you use to seal the tops?

[CaRaZaY]

.... AA grade marine ply to retain character of the place....... The cabinet is an older pine panelled.

I think I misread your original query in that I thought you specifically wanted ply/ liked the look of it. If you're not locked into ply then solid timber would be the go like others have said.

I built my own kitchen benchtops from some beautiful spotted gum 240x40mm. I ordered it DAR and biscuited and clamped at a mate's shop then I cut in-situ. They were ludicrously heavy to move around.

Mate recommended I use Adheseal Unobond saying the timber will tear apart before the glue will. It was easy to work with and the benchtop is still rock solid 14 years later.

Unobond Polyurethane Adhesive - High Bond Strength for Wood, Cabinets, and Joinery
– Adheseal


Gluing.Spotted.Gum.Benchtops-010.jpg

Benchtop_Cutouts 012.jpg

.

[oldwoodie]

I used a Cabot's water based benchtop finish
Quick drying and wears well. My benchtops were done 3 years ago and are still good.