Help wanted – Aircraft Plywood Specification 6V3B

Thanks again Tempest/Eric/Ed
I know precisely what’s I’ve got here (Grade B Beech)and I can now order replacement ply.

Silver biplanes is great site and the responses from you guys is this forum at it best.

Thank you for that link powerandpassion. A wealth of information on that site, not just on plywood!

Standard here :
http://silverbiplanes.com/SPECIFICATION_PDFS/British_Standard_V_2017/V3_1943_6V3.pdf

Hi Vega ECM,

So for your specific application depending on the three figure number that follows the 6.V.3B prefix, your wood will either be Grade B Beech ply between 1/32″ and 3/4″ thick, or Grade B Birch multi-ply between 1/4″ and 3/4″ thick.

Many thanks Tempest and Eric. The information is really appreciated

Hi ericmunk,

Sorry, I don’t know if the Grades correspond to the Lloyd’s GL I and II ratings.

I stand corrected. Does grade A and B correspond with Lloyd’s GL I and II ratings?

Does anyone know what type of wood is used in plywood specification 6V3B?

I believe this a British Spec from 1930 – 40’s possibly earlier.

Any help or leads greatly appreciated.

Hello Vega ECM,
According to my Molesworth’s Aeronautical Engineers pocket book, dated 1947:

6.V.3B can be translated as:

6V3 is high strength plywood for aircraft.
B is grade B.

To get the specific type, thickness and ply, you will need an additional number, eg:

V3/140 is birch, 3/32″, 3 ply, grade A.

If you have additional numbers, I can look them up on the chart.

Is that a thick 9-ply multiply? I have seen such as specification mentioned as an abbreviation for 6 vertical 3 broad. As in: grain direction for the layers.