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I made a wood filler using wood glue and sawdust to fill some stripped out holes in a shelf. The holes are maybe 3/8" x 1" deep so there was a fair amount to fill. Now it is a full 24 hours later and the filler is still not hard. I tried drilling a couple very small pilot holes and the bit came out with a soft malleable putty surrounding it.

I'm thinking that perhaps the pilot hole will help it dry since now the interior is exposed to air but I've never had this experience before. Is it normal for a deep hole filled in this manner to take so long to dry? How long should I expect wait?

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    Usually the larger the amount the longer the drying time. A small puddle of paint will take longer to dry hard(unless it is on an expensive piece) than paint brushed onto a wall. – crip659 Jan 10 '23 at 19:56
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    @crip659 - that makes sense. Do you think if I had fancier shelves the glue would dry faster? – But those new buttons though.. Jan 10 '23 at 20:22
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    Instant-drying low-viscosity CA glue in place of wood glue works wonders for this. Repeatedly add a little sawdust, apply a single drop of CA glue. – R.. GitHub STOP HELPING ICE Jan 11 '23 at 17:25
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    @crip659 Specifically, it's the depth/thickness of glue that matters. I've had really thick globs that didn't dry completely for months. I would guess the skin that forms on the surface prevents the center from drying out. – JimmyJames Jan 11 '23 at 18:23
  • Or use epoxy. That doesn't rely on air surfaces at all. – leftaroundabout Jan 11 '23 at 20:11
  • Use a small fan to blow air on the hole. It'll help the glue dry faster (assuming it's a drying type, not a curing type). – Huesmann Jan 12 '23 at 14:53

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If you read the directions on most wood glues, they'll tell you apply liberally and then tightly clamp the parts together so the glue oozes out. Puddles or densely pack glue will take a long time to harden, no air can get to it and it can't be absorbed by the surfaces. You'd be better off stuffing the hole with some glue covered toothpicks or using a 3/8" x 1" dowel pin and glueing it in place. It could take days to completely harden.

JACK
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    +1 for the dowel - that's the traditional cabinet maker's solution too. – Criggie Jan 10 '23 at 22:56
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    Thanks - part of the issue here is that the holes had not only widened due to breakage (particle board) but were not exactly straight and had become somewhat funnel shaped due to chipping around the outer edge. Bit of a mess and difficult to work toothpicks into the equation. I do like the dowel idea - maybe coupled with a bit of the sawdust filler which would be far less in volume that way. At any rate, here we are about 30 hours into things and the filler has dried *enough* to hold the female threaded fitting which was my goal. I guess that's the "answer", 30+ hours! :-) – But those new buttons though.. Jan 11 '23 at 02:55
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    @EatenbyaGrue For that sized hole(3/8) a dowel would the best. Toothpicks are good for small screw size holes that are stripped. – crip659 Jan 11 '23 at 12:33
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    @EatenbyaGrue, (this is late, but might help someone else) you could make the hole a bit larger to make the sides straight again so a dowel or toothpicks could be an option again. This would be done by using a drill or Forstner bit, or possibly a tiny drum sander or other abrasive on a small rotary tool. – computercarguy Jan 11 '23 at 22:27
  • @computercarguy - thanks. good idea. In my case that wouldn't have left a lot to work with but I see how that could be a winning strategy if there is plenty of wood surrounding the hole. – But those new buttons though.. Jan 11 '23 at 22:38