Nova SS wrote:
galamb wrote:
I've used the Baltic Birch (also sold as Russian birch and a name or two that I can't think of) for cabinet work and agree - it's very "pretty" stuff for plywood and in theory it should be (stronger) overall, because of it's additional plys, compared to other sheets of similar thickness.
One other note on using this as frame material and the potential lack of fastenability in the endgrain - if you follow WEST techniques for bonding, you can do so without the use of any fasteners - and while I personally still wouldn't go with plywood frames (agree that solid stock just looks so much better), West techinques show that it's both viable and successful in producing a sound hull.
I would have loved to use birch for the sheet work on the hull of my build but the big problem, at least up my way, is getting a solid answer as to what type of glue was used in the manufacture and the exact source of the plywood to start with.
There is/was some fairly high quality stuff from Finland around that used Urea glue for their interior panels and Phenolic resin for the exterior (which meets the waterproof/boilproof standards in North America), but what I see commonly available now is BB graded panels, from former Soviet Union countries that may or may not follow the GOST standard (Russia's version of the APA over here).
I have found very little information on these but read (can't remember the source) that their "ext" grades are sometimes bonded with melamine glue. While that is a (somewhat decent) exterior glue, it usually does not meet both the of the WBP standards.
Since none of the suppliers in my area could confirm the panels at least meet the GOST guidelines, and the panels have no stamps other than the BB (face grade), I elected not to trust them.
I guess my bottom line is - if you have a reputable supplier that can confirm the sheets are bonded with Phenolic Resorcinol glue then go ahead and use them, otherwise, I wouldn't want to find out the hard way that it's not a true WBP exterior panel....
You know Graham, your posts on plywood are always some of the most informative posts on the subject I think I've seen on here. Thank you for sharing your knowlege.
I agree.
Thank you for that galamb. Yes, I have confirmed that this exterior plywood from Latvia (often called "Finish Birch plywood"), not Russia, is laminated with waterproof/boilproof phenolic resign.
I'll check out the West stringer securing techniques as well.
Thanks Oyster for the stringer locating and hand held palm router tips. Sounds easy enough.
Grampa Steve