# Straight dowels vs spiral dowels



## Purrmaster (Sep 1, 2012)

I figured I should christen the new joinery forum with a question.

Is there any real difference in strength between a dowel join with straight grooved dowels vs those made with spiral cut dowels?

I ask because I've got some fairly long cut off pieces that I want to join end to end to make another board. I was planning on using dowels. I intend to glue the makeshift board onto another board so there will eventually be an edge grain to edge grain joint.


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## Handtooler (Jul 24, 2012)

I suspect not, but await the answers. They're both strong joints that I've used successfully.


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## waho6o9 (May 6, 2011)

+1 for HandTooler.


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## Dal300 (Aug 4, 2011)

In some of the cutting board I've made I just buy dowel rod, cut it to whatever length I need and scrape a knife along it in a few places. The scrapes give room for the glue bond.
I haven't had one come apart yet, but it could happen.


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## helluvawreck (Jul 21, 2010)

I don't see that there wood be enough difference to worry about so long as the two dowels you were comparing were made out of the same wood and were accurately made. But I really don't know the answer to be honest.

helluvawreck aka Charles
http://woodworkingexpo.wordpress.com


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## a1Jim (Aug 9, 2008)

If your concerned about strength there are much stronger joints than using dowels.


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## Kreegan (Jul 10, 2012)

I believe the spiral is to allow room for glue. Not really sure how successful that is. I've always just used whatever I have on hand.


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## tenontim (Feb 24, 2008)

Wood Handbook-Wood as an Engineering Material says that "glue joints should have a smoothness the equivalent of being sanded with 220 grit sand paper." That's pretty smooth. The glue itself doesn't give much strength, it has to bond the fibers of the two pieces being joined. I just use smooth dowels and glue and they work fine. +1 a1Jim.


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## wormil (Nov 19, 2011)

Scarf would be easier and stronger.


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## Purrmaster (Sep 1, 2012)

Can a scarf joint be achieved with a table saw or a miter saw?


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## SCOTSMAN (Aug 1, 2008)

Dallas said

In some of the cutting board I've made I just buy dowel rod, cut it to whatever length I need and scrape a knife along it in a few places

Oh Dallas the argument is made for a lathe in the shop. Alistair


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## wormil (Nov 19, 2011)

Can a scarf joint be achieved with a table saw or a miter saw?

Easily, I make them all the time. I built a very simple jig for my table saw that rides in the miter slot and has an adjustable angled fence. The fence pivots on the side closest to the blade and a series of holes on the opposite end allows you to adjust the angle. A cut off nail pins the fence into the holes. Basically it's a small taper jig.


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## gfadvm (Jan 13, 2011)

I was always of the opinion that the grooves were to allow glue to escape when putting the dowel into a closed hole. Otherwise the hydraulic pressure will make them hard to install and they sometimes want to 'back out'.


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## Dal300 (Aug 4, 2011)

That was my understanding also Andy


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## Grandpa (Jan 28, 2011)

and also my understanding Andy and Dallas. try to put a joint together with a smooth dowel that fits the hole. Add glue and push that together. Not me.


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