Cutting dovetails in Alder

[Edwin Santos]

Hi,
I was recently cutting dovetails in Alder, which seems to be a plentiful and inexpensive hardwood around here. I ran into issues with the end grain wood fibers breaking out badly inside the sockets when chiseling out waste. I use a fret saw to saw out most of the waste, trying to stay around 1/32" above the base line. Still even with this little material to chisel, I would end up with craters of break-out as I get further inside the socket.

This did not matter aesthetically because the craters were all hidden inside the joint, but I know it's there and I don't like it. I feel my chisels are very sharp.

Is what I am describing a typical characteristic of Alder?

What would you advise to mitigate this issue?

I usually try to undercut the inside of the socket slightly. I once read about a technique where you do the opposite, in other words purposely overcut so there is a hump in the joint, and then put the workpiece vertical in the vise and pare away the hump with a rocking, paring motion. I tried that technique but it didn't really solve the Alder problem.
Thanks

[Jim Koepke]

Even though Alder is by definition a hardwood, it is still soft like pine. It requires a very sharp chisel to pare end grain without the break-out you experienced.

If your chisels are sharp enough to pare very light shavings from the end grain, that may be as well as can be done.

Remember the thinner the shaving, the less tear out or break-out will result.

jtk

[Prashun Patel]

I get better paring of end grain when I skew my cut.

[bridger berdel]

score the baseline from both sides, and chisel from both sides.

[Bill McDermott]

Haven't used Alder. I have seen that in pine and even poplar. The old sharp thing may be the answer. But I have correlated that effect when driving chisels with a mallet. I almost never see it when paring with hand pressure. If you are talking thin enough slices (by hand pressure) with a sharp enough chisel, you may be able to get clean cuts. I find it noteworthy that a purely cosmetic issue, hidden inside a joint concerns you enough to post. I bet your joints are looking really good on the outside.

[Michael Fross]

I keep a chisel ground to 17 degrees (plus a microbevel) for use in softwoods. All in bevel angle is probably about 19-20 degrees. The edge would probably shatter in hardwood, but it given me clean dovetails in soft wood.

If you've got a good, but seldom used chisel give it a shot...I think you'll find it works wonders in soft wood. I picked this technique up from Rob Cosman.

Michael

[Edwin Santos]

I find it noteworthy that a purely cosmetic issue, hidden inside a joint concerns you enough to post. I bet your joints are looking really good on the outside.

Well you have a point, maybe much ado about nothing. It's a game for me, just trying to get better and better. Here's the box I was working on yesterday. The joints are not bad, but not quite perfect either. I'm playing around with a steeper angles for the heck of it, 1:4 in this case. I think that's about 14 degrees.

Alderjoint 2017-02-06.JPG

Alderjoint2 2017-02-06.JPG

[Jim Koepke]

Well you have a point, maybe much ado about nothing. It's a game for me, just trying to get better and better. Here's the box I was working on yesterday. The joints are not bad, but not quite perfect either. I'm playing around with a steeper angles for the heck of it, 1:4 in this case. I think that's about 14 degrees.

Those look fine to me.

The past couple of days has included playing with some alder. With my sharp paring chisels and taking thin shavings the end grain between the tails can be cleaned out without any breakout or tear out. My paring chisels are usually ground between 15-20º with a flat bevel, no secondary bevel. The waste between tails or pins is cut out with a fret saw.

Thin cuts with a sharp blade seems to be the way to get it done.

jtk

[Steve Beadle]

I was wondering if you're the same Ed Santos I once met years ago, who lived near the DQ (city name deliberately withheld)? I remember you making toy log trucks in fir or pine, and finishing them with a propane torch and dipping them in a bucket of polyurethane.

[Edwin Santos]

I was wondering if you're the same Ed Santos I once met years ago, who lived near the DQ (city name deliberately withheld)? I remember you making toy log trucks in fir or pine, and finishing them with a propane torch and dipping them in a bucket of polyurethane.

Not me, although I would love to see the other Ed Santos at work with his torch! Sometimes I get mistaken for a Edwin Santos who was a world class surfer in the 80's from Puerto Rico. At this point, I'd say I have the least impressive resume of the three Eds

[Edwin Santos]

Thanks for the replies. It does look like Alder just behaves a lot like a softwood even though it is technically a hardwood. Taking some of the advice, I found some success making a light establishing cut on each side to create a ledge at the baseline. From here I put the piece in the vise vertically and pared down the "hump" using thin angled slices and a paring chisel ground to a lower angle, just under 20 degrees. Alder is not my favorite wood for dovetailing but with these few changes in procedure, the breakout inside the joint can be kept under control.