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I repaired a small end table recently and one of the aprons used dowel joinery to attach to a leg. I drilled out the dowel since a couple were broken and I wanted then to all be the same. I replaced the dowel with some poplar dowel from a local hardware store. I then glued it back together.

I cannot be certain but in hindsight I think the dowels might not have been glued in and they were fluted dowel which the replacement was not. If I had used fluted dowel I think I might have been able to get away from glue and just used a wooden hammer to knock it closed.

When I think of fluted dowel I picture these guys...

fluted dowel pins

Image from HomeDepot.com

If I understand correctly that shape will allow the dowel to be inserted easily but make it harder to move around? I see these on economical furniture all the time and I never glue them.

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  • Are you certain they were poplar? It's not a particularly strong wood and I would be looking for high strength maple, birch, or oak dowels.
    – Ast Pace
    Commented Apr 14, 2016 at 22:03
  • @astpace it was labeled poplar at the store. It's what was there.
    – Matt
    Commented Apr 14, 2016 at 22:55
  • In my experience when I began using dowels, I just bought a long dowel from a big box store and cut them down to size. I began to realize that a 3/8 dowel and a 3/8 drill bit didn't leave any room for glue. When hammering the dowel in it left no room for glue to move up. For this reason I believe you should make scores down the length of your own dowels to allow for the glue to move and set along the joint to add strength, otherwise you aren’t taking advantage of the glue for strength. Just wood on wood and no glue doesn't make for the strongest joint.
    – Garrett
    Commented Dec 27, 2020 at 15:57

2 Answers 2

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There are two main purposes that I know of. First, the flutes allow air to escape and glue to fill the voids as you are inserting the dowels. Without them, it is possible that you would not be able to insert the dowel all the way into the hole. Secondly, the flutes are produced by compressing the dowel, and once exposed to moisture (glue), the compressed parts of the dowel will expand ensuring a very snug fit.

In some cases like Festool Domino tenons, it also gives the manufacture yet another opportunity to advertise their name.

I'll also point out that the tapered ends which allow for very slight variations in alignment to more easily fit together; without them, you'd need to be dead on when lining the pieces.

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If I understand correctly that shape will allow the dowel to be inserted easily but make it harder to move around?

Nope. The chamfered end is what makes insertion easier (always advisable to do this on any shop-made dowels).

The fluting is almost entirely to allow air and excess glue to escape so as to prevent a buildup of hydraulic pressure, which can at worst totally prevent a perfectly round, tight-fitting dowel from being driven home in a drilled hole — it just bounces back up if hammered home LOL

The commercial variety are said to be compressed but I don't know that all are, if so the idea is they swell once wet with glue and then lock in place (this is the principle used with biscuits). But regardless of whether they are or not it doesn't matter, a homemade dowel with no fluting* bonds as well or better into a hole it fits tightly in.

*But one or more scores or kerfs to allow air out.

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  • The premise for my assumption was based on my only experience with Ikea furniture. If it was designed for gluing it makes sense but it was never clear to me initially. Thanks
    – Matt
    Commented Apr 14, 2016 at 18:12

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