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Tom Blank
10-08-2012, 12:15 AM
I'm using dowels in 3/4" ply to locate jigs on a base and was going to use wedges in the ends of the dowels to help secure them in the jigs. Does it make any particular difference if you cut the kerf in the end of the dowel with the grain or across the grain?

Seems like with the grain would be the correct answer, but thought I'd check with experts.

Thanks,

Tom

Sean Richards
10-08-2012, 2:03 AM
I cut the kerf with the grain but first drill a hole where the the bottom of the kerf will be - otherwise you can find that the dowels will split

Philip Duffy
10-08-2012, 5:32 AM
I was taught to just use a chisel with the dowel in place and glued up. Whack it good and put the wedge in place with glue, let it dry and cut and trim, and sand the end. Works on Windsors. Phil

Bob Glenn
10-08-2012, 11:51 AM
I was taught to just use a chisel with the dowel in place and glued up. Whack it good and put the wedge in place with glue, let it dry and cut and trim, and sand the end. Works on Windsors. Phil

Yup. Works for me.

Joe Fabbri
10-08-2012, 11:56 AM
That's how ship trunnels are wedged. Leave about at least 3/8" (or 1/2") of the dowel sticking above the surface, then split it with a chisel. The extra length of the dowel protruding makes starting the wedge much easier and less likely to break on you. Then when you hit the wedge down flush with the protruding dowel, you would take a ship caulking iron and drive the wedge down a bit farther. I've also used the side of a drill bit to put flat over the wedge and hit down with a hammer. Just so long as the instrument is blunt and won't cut into the wedge. I think the side of a bit works pretty well here for that reason.

As far as splitting or kerfing with or against the grain, I couldn't really say.

Joe

Sean Richards
10-08-2012, 4:23 PM
That's how ship trunnels are wedged. Leave about at least 3/8" (or 1/2") of the dowel sticking above the surface, then split it with a chisel. The extra length of the dowel protruding makes starting the wedge much easier and less likely to break on you. Then when you hit the wedge down flush with the protruding dowel, you would take a ship caulking iron and drive the wedge down a bit farther. I've also used the side of a drill bit to put flat over the wedge and hit down with a hammer. Just so long as the instrument is blunt and won't cut into the wedge. I think the side of a bit works pretty well here for that reason.

As far as splitting or kerfing with or against the grain, I couldn't really say.

Joe

Hi Joe,

For trunnels you orientate the wedge perpendicular to the grain of the wood that the end of trunnel is passing through - at least that is what a Norwegian boatbuilder showed me. So I guess they didn't really worry about the grain of the trunnel.

Sean

Steve Baumgartner
10-08-2012, 4:28 PM
Hi Joe,

For trunnels you orientate the wedge perpendicular to the grain of the wood that the end of trunnel is passing through - at least that is what a Norwegian boatbuilder showed me. So I guess they didn't really worry about the grain of the trunnel.

Sean

That's how I was also taught. If you put the wedge parallel to the grain in the non-dowel part, you run a serious risk of splitting it. The orientation in the dowel might make a little difference in glue joint strength, but I doubt it is much because either way you are driving the wedge parallel to the grain fibers of the dowel.

Steve

Joe Fabbri
10-08-2012, 5:00 PM
Yes, the split of the chisel (or kerf if you saw it) and the wedge itself have to be perpendicular to the grain, so that the wedging action is with the grain, not against it, which could definitely split it.

What I am not sure about, though, is if the grain orientation of the trunnel/dowel matters much.

Joe

Bill Houghton
10-09-2012, 2:23 PM
I imagine that, when you say, "with the grain," you mean, "in line with the growth rings." If your hole is deep enough (say, and this is a flying estimate, twice the length of the wedge), it probably won't much matter. If it'll make you feel more secure, I think the split in your dowel is less likely to "travel" if you split it across the growth rings.