05-28-2010 02:25 PM - edited 05-28-2010 02:32 PM
I want to make a large thick slab table top out of solid cherry (about 50 square feet). I can get 4/4 cherry for under 4.00 bf from a local mill but all he has is 4/4. The nearest place that has 8/4 stock wants $7+ bf. For a 50sf top that amounts to about $400 difference.
I see three options:
1) spend the extra $400 and glue up solid 8/4 boards.
2) glue up the boards to build up the thickness and the width over the entire top (laminating).
3) glue up the 4/4 boards to width and then build up just around the outside to the thickness- Then secure it to 3/4 plywood with screws in slots to allow for movement of the solid top.
Any opinions or experience?
If 2) is an reasonable option should I make thick boards first (6-9" wide) and then glue them up to make the wide top or try to glue it up so that the joints between the boards are offset? Also should I alternate the grain?
Standard wood glue?
I have done this before on smaller projects but nothing on this scale.
05-28-2010 02:58 PM
I would think a solid cherry top of 50 sq Ft 2 inches thick will weigh close to 300 Lbs. Using the 35 lbs per cu Ft weight for cherry. I would go with just the edge being thick or layered and using 4/4 for the rest. Roly
05-28-2010 03:22 PM
I agree with Roly but have also only done smaller scale projects this way. I think it would be the best option for a large scale project as well. I've had very good results as long as you keep the grains similar along the edge.
05-28-2010 03:59 PM - edited 05-28-2010 04:01 PM
Build up just the edges (about 2" from the finished edge should be about right).
Tables always are about edges, not center of mass. The center of the tabletop could be 3/4", it could be a foot thick. There's no way to tell. The thickness is detected only at the edges. So make the center of mass with your 4/4 wood and only worry about the visual cue at the edges.
BUT... watch for cross-grain situations. To that end, I'd lay the laminations at the ends of each individual board prior to any glueup, then joint them and glue them together as the table top. That ensures that the joint lines match up and you eliminate the need to glue on the applied under edge onto a table surface as an extra step after it's made.
05-28-2010 05:05 PM - edited 05-28-2010 05:07 PM
Another option would be to rip your 4/4 lumber to about 1 13/16" wide, set them on their edge, glue and clamp together. If you have a 12" Planer, glue up boards just under 12" wide and plane the glue-up to 1 3/4" thickness. Then carefully clamp the next section flush with the previous one and repeat until all segments are joined. Then finish off with a RO Sander.
Another way to dress the top is find a shop with a large drum sander that could handle your table top in one or two segments.
Titebond III, which is waterproof.
05-28-2010 07:23 PM
I vote with the majority. No sense in wasteing that much gorgeous cherry where it wil never be seen. With the edge treatment probably less risk from all those joints moveing. When you glue up the edges let it dry very well before working as you could get some glue drift depending on the glue you use. Yellow glues can drift.
I scoffed at this til I glued up and turned legs for a stool. After 4 month I ccould feel the glue line edge where drift had occured.