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I am making a top for a small child's table. It is 30" square and I jointed 3 10" wide pine boards to make it.

While I had it in a vise and was planing the end grain to clean up the marks left by the saw, the vise "let go" and it fell to my garage floor. The middle board suffered a small crack as a result. (The picture is a bit awkward and the angle isn't the best, but the split is on the end. The board is leaning against another one)

You can see a .25" chisel next to it for size comparison. I tried getting glue [edit: Titebond II] in the crack and using clamps to pull it together, but it is so small I wasn't able to get it in. What is the best way to repair this?

enter image description here

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    It's not a bug, it's a feature! – Daniel B. Apr 10 '15 at 21:20
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Catalog sites or local woodworking stores will likely sell a glue injector- it looks like a big needle. It's most often used to inject glue into chair joints.

Use a small screwdriver to open up the crack a bit, then use the injector to get glue in there, then pull the screwdriver and let the crack close.

If the crack is small, you may not even need to clamp it.

Of course, you could also turn the crack into a feature with a dutchman patch (instructions), like this:

Dutchman patchImage courtesy of woodworkingtalk.com

There was a question about the picture used to describe the Dutchman patch. Related discussion about the Dutchman Patch: What is the difference between a dutchman patch and a butterfly patch?

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    What is a Dutchman patch? Adding that to the answer would be helpful. – Peter Grace Apr 10 '15 at 22:51
  • The link you provided for a dutchman patch isn't what you've got in your picture. Try this one: wwgoa.com/custom-cut-butterflies (butterfly joint = dutchman joint?) – Daniel B. Apr 12 '15 at 19:48
  • I didn't know about the glue injector. I am going to give that a try. thanks! – user234 Apr 13 '15 at 16:04
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You didn't mention what type of glue you're trying to use for the repair, but if this is just a minor cosmetic defect it may be a nice application for CA (cyanoacrylate) glue, aka superglue. It's thinner than wood glue so it'll be easier to get it to seep into the crack.

You can use compressed air to blow the glue into the crack, or if the crack goes all the way through you can use a vacuum to pull it into the crack from the other side. As with TX Turner's glue injector suggestion, it will help if you can bend or pry the crack slightly more open so it's easier to get the glue in.

Some other options include breaking or cutting the board all the way through and gluing it back together, or adding an inlay. If you go the inlay route, you could either use a butterfly inlay to strengthen the repair or if it's a really shallow crack, you could use a purely decorative inlay. Or you could take a page from the turners' playbook--a common solution for repairing cracks in turned pieces is to use a liquid turquoise inlay. If you do this, you'd probably want to carve out a larger channel as you would with the "solid" inlay techniques.

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I have used the very thin CA glues such as this stuff from Titebond in the past. It works very well. It is about as thin as water. If you plan on finishing the surface with a stain, you should probably test it first on a scrap to make sure it won't blotch. Ripping down the crack and re-gluing works well also, but you lose some width from the board. enter image description here

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it is so small I wasn't able to get [the glue] in.

Diluting slightly can help with this, then a fine brush will usually work for application. You can also work the thinned glue in with the tip of a cocktail stick or bamboo skewer. The best method though is to inject the glue deeper into the crack with a hypodermic needle.

To be honest I would probably just fill this myself because it's so fine.

The simplest method is to get glue into the crack and then just sand the piece lightly to mix sanding dust with the glue. One pass might be enough here.

Although glue + sanding dust is rarely a good colour match to the wood despite what many guides say (it's nearly always darker) for a crack this fine you'll never see it on the finished item.

Either glueing or filling you will inevitably get some glue onto the surface of the board. Once the glue has had a chance to fully dry sand further (or better, use a card scraper) to remove the surface fibres contaminated with adhesive. Check for any remaining glue by dampening the area with spirits, if you see no pale stain where the glue was you've gotten it all.

the vise "let go" and it fell to my garage floor.

To prevent this in future, consider lining your vice's jaws with leather. It works very well, greatly improves grip while simultaneously reduces the tendency to mar the workpiece.

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  • thanks for the tips. I do have it lined with leather. The problem is that it is a $15 vise from Lowes. The jaws are out of line and only clamps on the bottom 2". the upper 4" never fully meet the wood. I have since purchased a good 10" Record that feels like it could hold an elephant. – user234 Apr 13 '15 at 4:14
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When it is that small, you can even get a way with a little wood putty.

Another would be to mix a little little sawdust in some epoxy or superglue and 'patch' it, then sand when dry.

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First take a razor blade and make a small thin sliver. Use it to clean out the crack. With a thin amount of Tight Bond III, work the sliver into the crack and tap it in place. Weight it down for about a day and then clean up with the razorblade.

Never use compressed air with polyurethane or cynoacrilates!

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  • Could you explain your bolded sentence? What is the problem of doing so? – Martin Bonner supports Monica Jan 28 '19 at 12:21
  • @MartinBonner My guess is that is in reference to Rob's answer where he suggested blowing the glue into the crack. My guess is that you might possibly blow the glue off the surface an onto something you don't want the glue on. Probably a minimal issue unless it happens to blow back on you - especially if it hits a sensitive spot like an eyeball. – FreeMan Jan 29 '19 at 19:21

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