Gluing and clamping natural edged slabs

[matt tennessen]

Stepping into uncharted waters and looking for a tip before I proceed. I've been wanting to build a table top out of a slab for a while and recently came by two "smaller" pieces that were too cheap to pass up. They are 10/4 black walnut cut most likely from a main branch. They each are 8' x 14"-17" and appear to be slices from the same branch. I want to rip one edge on each, joint the edge with my router and then glue them up maintaining a natural edge on each side. My issue is clamping. The bark is still on there but don't wish to preserve it, would it aid in acting as a pad for the clamps? I'm ok with a little imperfection here and there, but i don't want to start clamping and find that I'm crushing the sapwood edges. Any advice would be much appreciated. Thanks.

[Jamie Buxton]

Walnut sap wood is a little softer than heartwood, but not much. A clamp pad applied flat won't ding it.

If the live edges have a severe angle on them, so your clamp pads won't sit flat, you can make blocks to help. A block will be wedge-shaped, so one face sits flat on the live edge, and the other face provides a flat spot for the clamp. At the narrow end of the wedge, there's a lip to hook over the pointier side of the live edge, to stop the wedge from sliding when you tighten the clamp.

[James Baker SD]

I built a conference table out of a maple slab with the raw rough edge still on one side. I resawed it into two pieces and glued them together. Biggest problem I had with clamping was getting a secure grip on that uneven edge. I ended up hand carving shims that matched the raw edge on one side and was flat on the other for the clamp. Each shim had to be unique and it took the better part of a day to make them all, but I had secure clamping surfaces.

James

[matt tennessen]

yeah, I was planning on cutting some 2x4 scrap for cauls on the live edges as well as running a board across to keep it glued flat.
and since I have your attention, any good suggestions for removing that bark and filling a few knots? I've heard of a few people using ground coffee with epoxy to hide the knots in darker woods like walnut, I'm planning on testing that out, otherwise I'll just use walnut sawdust. There are only a couple of small spots.

[James Baker SD]

Matt,
I cannot help much on your recent questions. My client wanted as natural a table as possible. Most of the bark just fell off in my hands. There were some decayed areas revealed only after resawing (in the legs, not the top) and some decay along the natural edge. I used narrow carving gouges to cut out the rotted wood, but little else. The discoloration remained, but the wood was all solid. It was what the customer wanted (he came to my shop and approved it), so I did not fill any defects in the wood and the bark pretty much took care of itself.

James

[Jamie Buxton]

... any good suggestions for removing that bark and filling a few knots? I've heard of a few people using ground coffee with epoxy to hide the knots in darker woods like walnut, I'm planning on testing that out, otherwise I'll just use walnut sawdust. ...

Sawdust in glue generally makes a granular surface, so it is easy to notice. On walnut, I generally use pigmented epoxy. I can flow it into cracks, or around loose knots, and it looks very much like a natural stripe of colored wood.