Posts: 11,420
Threads: 0
Joined: Dec 2002
Gents, I need to make a thicker board. These will be 7" wide, paduak. The "top" board will be quartersawn, the "bottom" will be flatsawn - because these are what I have.. Both 1" thick, glued face to face to make 7" by 2" thick board.
Foresee an issue here? Or is the difference between the flatsawn and quarter sawn expansion rates (1.9% net) small enough to be okay? Was also thinking about using epoxy, as it has a bit of flex to it.
MAKE: Void your warranty, violate a user agreement, fry a circuit, blow a fuse, poke an eye out...
www.makezine.com
No Good Deed Goes Unpunished
Posts: 12,677
Threads: 0
Joined: Jan 2010
Location: Lewiston, NY
(12-14-2018, 02:15 PM)jgourlay Wrote: Gents, I need to make a thicker board. These will be 7" wide, paduak. The "top" board will be quartersawn, the "bottom" will be flatsawn - because these are what I have.. Both 1" thick, glued face to face to make 7" by 2" thick board.
Foresee an issue here? Or is the difference between the flatsawn and quarter sawn expansion rates (1.9% net) small enough to be okay? Was also thinking about using epoxy, as it has a bit of flex to it.
That's about 1/8" difference over whatever MC range you are considering, so you are going to feel the difference at the edges for sure. But it probably won't fall apart as long as you use glue with some give to it. FWIW, any of the PVA glues should work better than epoxy in that regard.
One area where you could run into trouble is if one or both edges of the glued up board are part of some assembly. I wouldn't use it for a stile or rail of a passage door, for example.
John
Posts: 11,420
Threads: 0
Joined: Dec 2002
(12-14-2018, 05:38 PM)jteneyck Wrote: That's about 1/8" difference over whatever MC range you are considering, so you are going to feel the difference at the edges for sure. But it probably won't fall apart as long as you use glue with some give to it. FWIW, any of the PVA glues should work better than epoxy in that regard.
One area where you could run into trouble is if one or both edges of the glued up board are part of some assembly. I wouldn't use it for a stile or rail of a passage door, for example.
John
Excellent thanks.
MAKE: Void your warranty, violate a user agreement, fry a circuit, blow a fuse, poke an eye out...
www.makezine.com
No Good Deed Goes Unpunished
Posts: 7,579
Threads: 0
Joined: Jan 2005
Location: New Zealand
How important is it that the glued up piece stays flat. Likely result of any movement is that the combined piece will cup slightly if moisture levels change. Enough to notice? That I don't know. Depends what seasonal swings you get in your climate.
Posts: 1,014
Threads: 0
Joined: Apr 2011
The cupping risk I think is the greater concern as that may result in delaminating.
+1 on PVA
I face glued quarter sawn zebra wood once but only along edges to build up thickness for an island counter top for a customer. 7 years later no problems that I’ve heard of with that.
Ray
