Marine Ply & do we need it in Model Construction?

[derekwarner_decoy]

Hi PD's ....I found this information whilst searching for cedar wall planking..........[that I can rip up with my new baby Proxon table saw] .......I was certainly suprised as I too assumed that marine ply was manufactured with super duper isothermic/liophobic type glues........ .....Derek

PS.....the following is a real good bed time story on the above noted adhesives ......... type glues

http://www.cheric.org/research/tech/periodicals/vol_view.php?seq=119620
______________________________________________________________________________________________________________________________________________________________________________________

"The Myth about Marine Ply
 
Many Australians grow up with the belief that Marine Plywood is a ‘special’ product made with secret adhesives that make it virtually indestructible.  

This is an urban myth.

The adhesive (glue) that is used to bond the veneers of Marine Ply together is the same as any other structural plywood that is manufactured in Australia.

WHAT IS MARINE PLYWOOD & WHY IS IT SO EXPENSIVE?
A boat travelling through water is subject to plate action from waves & floating debris. Marine Ply is designed to absorb these forces due to the fact that this plywood is the closest to solid wood. In fact it is better than solid wood – defects have been graded out.

Marine ply is manufactured using the highest quality grade of veneers.  These veneers don’t have defects & thereby eliminate core gaps when the sheet is cut. These veneers aren’t available in volume compared to lower grades. As these high grade veneers are used in every layer, marine plywood is dearer than other grades such as structural plywood.

If your plywood project doesn’t have a sail or a motor attached to it, you shouldn’t be using Marine Plywood.

STANDARDS
Bond: Type “A” (Phenol Formaldehyde)
Face Grade: Manufactured with “A” grade veneers on both faces.

With thanks to Boral Hancock Plywood"
___________________________________________________________________________________________________________________________________________________________________________________________________

Phenol-formaldehyde resins make excellent wood adhesives for plywood and particleboard because they form chemical bonds with the phenol-like lignin component of wood. They are especially desirable for exterior plywood, owing to their good moisture resistance. Phenolic resins, invariably reinforced with fibres or flakes

[big-geoff]

Mmmm very informative.

Last time I used Marine ply was when I built my 20ft Day sailer.

I have not seem it sold in 1/16 thickness though, if you know where they do please let me know.

Geoff

[R.G.Y.]

 I always use ply from scraped furniture, coated with resin, no problems.

[chipmonk]

The designation for marine ply we use at work is birch ply. That is it is only made from selected grades of (guess what) birch. It has at least 5 plys (well 6mm plus does) and all the plys are uniform in thickness. It is very pale in colour and the grain runs across the short dimension of the sheet. We use it as its much more stable that standard ply which can be made from any hardwood. It's also great for making boat boxes .
Cheers Chris M