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I recently came into possession of a wonderful turned maple bowl however there is one downside. There is a small crack about halfway through the bowl. The crack goes fully from top to bottom but not fully left to right. The bowl is not about to fall apart but I think after a while of putting fruit into it, or several used as a salad serving bowl the crack would spread and weaken.

Is it possible to glue this and (bonus points) glue it with a food safe glue?

enter image description here

  • use wood putty. – user2313 Jul 7 '16 at 0:11
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I suspect that it actually isn't going to get any worse. However, what is generally accepted practice is to use epoxy. If you want to hide the crack and patch you can mix in some sawdust, in this case maple sawdust would be best. As an alternative, you could mix in some other colorful stuff to make it pop. Ground turquoise is a common choice for this.

Of course any glue or epoxy will leave a bit of a mess and will need to be cleaned up. You might end up needing to refinishing the whole piece. If that is the case, nut oils are food safe and so is carnuba wax, which is hypoallergenic.

  • Another alternative to maple or turquoise filler would be black or dark brown, to mstch the other (spalting?) lines. Pretty wood, and the simple bowl shape displays it nicely. – keshlam Mar 19 '15 at 14:13
  • Is there a specific epoxy I should be looking for? I know there are many options when I go to Lowes' epoxy aisle. – Brad Mar 19 '15 at 15:01
  • @Brad unfortunately I haven't done any of this myself. I just know many turners who have. But I did a google search for 'epoxy for wood' and got a lot of products. I imagine any of them would work, I'd look for the ones that claim to be easier to work with. – bowlturner Mar 19 '15 at 15:05
  • I've used regular two-part epoxy colored with black airbrush paint to fix holes and cracks in alder. It planes cleaner than any wood but I'm not sure how food safe it is. – saltface Mar 23 '15 at 17:30
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    I've mixed coffee grounds in for a dark finish, works very well. – SqlACID Mar 26 '15 at 16:32
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If it were mine, I think I'd either try a tinted epoxy or epoxy-based filler. Or I'd accept the crack but stabilize it with a butterfly inlay... or just accept the crack as part of the character of the piece.

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    +1 for the Dutchman idea. Done properly, that could be really neat. – FreeMan Mar 19 '15 at 13:20
  • Could you explain the butterfly inlay some more? How involved is that? Do I need anything special to do it? – Brad Mar 19 '15 at 14:59
  • A butterfly inlay on a curved surface? That's a lot of bragging points right there. Brad, a butterfly inlay is a bowtie-shaped piece of wood that you create a recess for, that spans the crack, stabilizing it. You typically orient the grain of the 'dutchman' perpendicular to the crack you're bridging for strength. Done in a contrasting but complimentary color, it can be a feature as well as a fix. You'll see dutchman patches on plywood- ever notice those football-shaped bits of odd wood? Those are dutchman put in to fix a knot-hole. – TX Turner Mar 24 '15 at 20:25
  • I think it's doable, though not easy.. Keep it small enough that you can treat the bowl's surface as approximately flat . Clamp the bowl in place, clamp template to bowl, rout. Clamp template to somewhat thick patch stock and cut out the insert. Trial fit, mark intersections with both surfaces, remove and sand/bandsaw to near those lines. Glue in, and lots more sanding to match the edges and fair the curves. This winds up being something more like carving than turning, admittedly; tinted epoxy is probably much easier! – keshlam Mar 24 '15 at 21:18
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Frank Howarth made a great video about how he "repaired" a cracked wooden bowl.

The rough turned maple bowl that I wanted to finish next had cracked. The crack was at an angle to vertical when the bowl was sitting normally. I cut out the section of the bowl with the crack on the band saw. Then I build a new segmented piece to take the place of the section. In this new section, I continue the idea of the chevron pattern, and add more detail. I give the chevron pattern branches by adding alternating pieces of birch and walnut wood on either side of the pattern. I also add a walnut ring at the top of the bowl so the segmented pattern has something to die into. Then I turn the whole bowl down to a finished piece.

He made a feature out of it

enter image description here

You'd have to be ambitious to do what he did but it might serve as inspiration.

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Due to the size of the crack a mechanical repair would be best like the aforementioned butterfly or stitch inlay or in lieu of that an epoxy would work. I wouldn't try to color match with dust or pigment as it just plain won't match and may just become an eye sore. If you want to color it go with black or some sort of metallic mix. CA glue, aka super glue, probably won't work here - it's too large of a crack. I wouldn't do it on my bowl. Filling it with gap filling or thick CA will probably result in a mess, also CA glue is brittle while epoxy can flex a little bit with seasonal movement. I use CA glue for hairline cracks, not open, through cracks. And you would never clamp this back into place - there is a reason it split in the first place so don't force it back. (Shrinkage, seasonal movement, too close to pith, internal stresses, etc)

For the epoxy generally almost any two part epoxy would do. Using blue tape, tape off one side of the crack so it doesn't just spill out all over. and fill. After dry remove tape and sand bowl or at least the local area and refinish with mineral oil, wax or a combo of those or walnut oil. Boom you're done.

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Since the surface would need to be cleaned up manually (not on a lathe), try CA glue and clamp it together. Much less mess than epoxy to clean up. The CA glue will be safe after fully curing.

  • What does CA stand for? – Brad Apr 6 '15 at 21:36
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    Cyanoacrylate--aka superglue. – rob Apr 6 '15 at 21:49
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Not enough rep to add a comment but most glues are food safe when dry. The drying agents may have toxins in them but they evaporate and the dried glue is okay. Obviously you'll want a glue that's waterproof when dry such as Titebond III

The Wood Whisperer has a good post on this

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You might want to get the "gap-filling" variety of CA. It's nice and runny and should seep nicely into the void without a lot of coaxing and, of course, as the name suggests, it will fill the gap. Personally, I wouldn't bother with clamping which will just put undue stress on the glue. If this crack had been in the bowl when the turner was making it, he/she would certainly have patched it in this very manner. It probably developed after the wood continued to age/dry-out after the finish was completed. You are just trying to get something to patch the opening. You can find it at the big name woodworking stores and online.

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