Epoxy or Bowtie or Nothing? Slab crack

[Patrick Irish]

This is the under side of a slab that's 2" thick and 50"x22". Gonna be a coffee table.

Is this crack something I NEED to deal with? I'm no expert and don't know if it's a structural thing. The slab is dry but in colder NorCal garage.

If I should do something, is epoxy or a bowtie better? I have epoxy here and never done a bowtie before. I'd order the Jasper bowtie router template and bit kit if I were to go that route.

[Jamie Buxton]

Whether you need to do something about it depends a little upon your design. If you're going for the live-edge slab top look, you maybe don't have to do anything. It might move a tad during the seasons, but generally that's not an issue in that esthetic.

A related question is whether this slab is dry. If it is still kinda wet, it will shrink some as it dries further. That shrinkage may encourage the crack to propagate further. If that is an issue, you could put in a bow-tie. Me, I'd put the bow-tie in the table edge. It will prevent propagation, but be a little less distracting than if it is on the table top.

One more thought... A bow tie has history, because it is easy to cut with hand tools -- a chisel. But that's not the only shape you can use, particularly in the age of power tools. You can use any shape that is bigger at the ends than in the middle. I've seen "bow-ties" that look more like a dumbbell, or like a doggie bone. I've even seen one that looked like two stars joined by a bar.

[Harlan Barnhart]

Patrick, the design of your project is probably the important factor here. A bowtie could look fantastic but they can be deployed carelessly as well, not all of us are Nakashima. I would dress that edge up, trim off as much of the crack as possible and fill it with darkened epoxy. I've done it many times on many types of defects, knots, cracks worm holes ect... and haven't regretted it yet. It finishes fine and comes out looking like a dark streak in the wood.

[Patrick Irish]

No specific design other than a live edge coffee table. Going to use Waterlox for sealer/stain. Legs will be out of oak. Just my first go at a slab table and joinery stuff. I'm 34 and getting more into woodworking.

I followed a youtube that made making bowties look easy. I went to cut a bowtie with a jig saw, then trace it on the slab, cut out majority with a trim router and finish side with chisel. Well I made the first bowtie really sweet but it was curved and I figured my chiseling would suck and the bowtie not fit right. I then tried making a standard bowtie with straight sides using a jig saw and that was a joke. I need a bandsaw. I got so frustrated and had to walk away and call it a night. Waster 1.5 hours and made no progress.

I don't want to cut the side down really. I'll look at it more tomorrow. Might tackle the legs and order that inlay kit.

[Sam Murdoch]

The bowtie this close to the edge would not likely be very effective, IMHO, as the tension deeper into the body of the slab could continue to open a crack. Lots of theorizing here. My choice would be to bore a 3/32" hole at the very end of the visible crack and deep without penetrating through the face. The hole will serve as a cut in the grain that is opening - in effect stopping the grain from continuing to open on the same path. Then with a masking tape dam build up the epoxy in the crack (and hole).

[Jim Becker]

If this is the underside, you can inset a metal strap to hold it stable. If on top, I'd use a bowtie.

[Chris Kiely]

I'd leave it. I don't think its going to be an issue, given its location.

Or you can try something like this. Much easier than a bowtie and more contemporary:


IMG_4171.jpg

Apologies for the sideways.