Plywood Characteristics

[Steve H]

Hi

I am having some trouble sourcing some good plywood for a Titan 39. I am in Wellington New Zealand. I cannot get baltic burch or Australian hoop pine (as suggested to me by harley). The plywood supplier said to go down to the factory and see what they have but i don't really know what to look for. So what characteristics am i looking for?
He suggested normal burch ply, any suggestions?

Thanks
Steve

[Grant Bunter]

Steve,
While baltic birch is better (mostly because it warps less and is a bit nicer to work with), it's not the only acceptable ply.

The criteria is reasonably simple.
Look at it and you want to see (at least) 5 plies of equal thickness.
Not 4 plies equal and a "finish grade" thin veneer.
Then look around the edges and you want to see as few gaps in the ply ("voids") as possible.
Of course that doesn't tell you how many voids may be in the middle of the sheet, but you will pay the earth for void free material.
You also don't want to see a large amount of "football shaped" patches in the faces, which have been used to fill defects.

Radiata pine ply is fine, all my builds have been done with that with no problems to date.
If you cut what you need as you go, that tends to lessen warping, but the plans address warping anyway.
The major producer of radiata pine ply worldwide is Arauco. It's sold in Australia, so may be able to be found in NZ too. We have local producers of radiata pine ply as well.
If you go that way, try to find the flattest panels you can to start with.

Harley has used Italian Poplar with good results for even lighter cabs.

I found very few suppliers of Baltic Birch in Australia, but see if your guy has Finnish birch.

You don't need marine ply, it's much heavier and costs more.

Finally,
Ply is graded. AA means pristine faces on both sides. Costs a lot.
You are looking for BC, CC, or, if it's ok, CD grade.
I got some non structural CD grade sheets that were pretty good. Non structural once again is a bit lighter than structural grade.

Hope this helps...

[Rune Bivrin]

I found very few suppliers of Baltic Birch in Australia, but see if your guy has Finnish birch.

Sorry to be snarky, but try to locate Finland on a map and see if it might not be right next to the Baltic Sea...

[Grant Bunter]

I found very few suppliers of Baltic Birch in Australia, but see if your guy has Finnish birch.

Sorry to be snarky, but try to locate Finland on a map and see if it might not be right next to the Baltic Sea...

My point exactly Rune!
For whatever reason, here it is very difficult to find baltic birch.
However, there seems to be much more Finnish Birch available.
I have no idea what drives local market when it comes to differentiating between the two...

[Harley]

Steve. As suggested in my pm, try SD radiata pine ply from the West Coast.

You just can't get Baltic ( Finnish or Russian ) here in NZ unless it's pre-coated sign or deco board. Trust me on that.

You can try and get Italian Poplar. If you look hard enough, you'll find Australian Hoop Pine.Surely there must be at least one ply specialist in the Wellington/Manawatu district. Don't get any ply from the large hardware stores or you'll regret it.

The hard facts of life are you have to be prepared to pay good money for the right ply for these cabs. If you want to go cheap, then you must have time and effort to waste IMO.

Sorry I have to put it to you like that, but this advice is meant to help, not criticise or chastise.