"blueman" wrote in message
...
blueman writes:
Still trying to minimize sag and tearout on my bookcase project.
Doubled-up 3/4" plywood sides and shelves with 46" inch span and shelf
pins.

I am trying to choose now between Baltic Birch (13 plys) vs. Natural
Birch with poplar core. Baltic Birch is almost 2x the cost.

Questions:
- Will Baltic Birch give significantly less deflection?
- Will Baltic Birch be less susceptible to tearout on the shelf pins
under heavy weight?

I am going to be painting the shelves.
Still any difference in terms of surface hardness or paintability?

Overall, is Baltic Birch worth the cost typically?

Thanks

Also, does anybody know the "typical" Modulus of Elasticity (in N/mm^2
or PSI) and density (in Kg/m^3 or lb/ft^3) for:
Baltic Birch plywood (assume 13 ply for 3/4" thickness)
Birch plywood with Poplar core (assume 7 ply for 3/4" thickness)


Forget the science, Baltic Birch is stronger than standard Birch ply. If
this is a really heavy duty shelving unit, BB would be better.

What are you planning on storing on this unit that qualifies it as heavy
duty?

Dave