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I learned about the thousand cankers disease of black walnut at our Guild meeting last night

February 10, 2010 By

Thousand cankers disease: Photo from the Missouri Dept. of Agriculture web site.

I cannot imagine the possibility of black walnut (Juglans nigra) disappearing from my shop, more than I can imagine not having a shop to practice the craft I love. But that is exactly what could happen if the pest that spreads thousand cankers disease has its way. Already, the disease has been devastating to black walnut trees in Western states. Please read about this on the Missouri Department of Agriculture’s web site.

Lonnie Messbarger (e-mail: lonnie.messbarger@mdc.mo.gov), the Resource Forester with the Missouri Department of Conservation (MDC) in the St Joseph, MO office, visited us during our Woodworkers Guild meeting last night. He talked about the huge threat posed by the walnut twig beetle (Pityophthorus juglandis) and an associated fungus (Geosmithia sp. nov.). I invite you read this paper from MDC, and to help spread the word about this threat.

Although the disease has not been found in “…the native range black walnut trees…” in Missouri or other Midwestern states, much work is concentrated on finding answers, and solutions. Please help spread the word; Lonnie asked we contact the Department of Conservation Forester to arrange for sampling and testing of suspect trees. The disease starts near the top of the tree, and spreads downward, ultimately killing the tree with thousands of cankers where the beetle penetrated the bark.

What we can do as woodworkers: Lonnie suggested that if we buy wood from Western states on Craigslist, eBay, etc., we should make sure that it has no bark, as the beetle is present only in the bark. If we buy lumber in person from someone in the Western states, request that logs and/or boards be de-barked prior to loading them, and moving them to the Midwest.

What we can do as woodworkers – based on additional feedback from Lonnie:

…Our insect and disease expert saw your posting on the Woodworking Examiner (National Edition, Examiner.com) website, and sent me an update.   The national experts dealing with the 1000 canker problem are recommending that folks not move any walnut wood (lumber, logs, firewood) from the West to the Midwest.   That includes even if the bark is removed.  This is their “more safe than sorry”  take on the matter since they are not 100% sure of the biology of this insect and disease.   I would tend to agree with them.   I am sure they will refine this in the near future as they learn more…

Lonnie Messbarger, Resource Forester
Missouri Department of Conservation
Northwest Regional Office
St Joseph, MO
(816) 271-3100

My thanks to Lonnie for his very proactive approach to staying involved with our community, and with forestry issues in general. He is also active in the St Joseph Woodworkers Guild, as our liaison for Arbor Day activities and just about everything involving wood and lumber.

— Al Navas

Filed Under: Blog, Education, Featured Tagged With: , , , ,

Preparing a hollow mortise chisel

February 4, 2010 By

One question from a reader prompts me to illustrate the process I use to prepare hollow mortise chisels before I even approach the benchtop mortiser.The process is called “tuning a hollow chisel”; it prepares the chisel for efficient cutting of the mortise, and eases penetration into the wood while minimizing burn marks. This results in smoother mortise walls, faster cutting, and better chip ejection while keeping the chisel cooler. So far I have not had to sharpen any of the drilling bits on any of the chisels.

In this photo you see the hollow chisel as received. The grinder marks are plainly visible:

Just like a bench chisel, the sides of the chisel should be lapped using either sandpaper or, as I show here, with sharpening stones. Following preliminary lapping on the 1,000-grit stone, I continue with the 6,000-grit or finer stone:

In this next photo you see how the steel begins to shine, and the tool marks have disappeared near the cutting edges – not quite ready for work, the chisel is getting close to being ready to cut:

Next I use a diamond-covered abrasive cone, to sharpen the inside surfaces of the tip of the chisel. The cone holder is part of a set available from various sources:

Careful inspection is a must, before using the chisel. Look carefully at the inside surfaces, to make sure the cone has left smooth, shiny surfaces:

Yup, that is the BenchCrafted tee shirt. And it is a shameless plug for the company that makes, along with 11 other winners, the Popular Woodworking magazine’s Best New Tools for 2009, the BenchCrafted Tail Vise. I was the lucky recipient of one tee shirt at the Valley Force conference:

To my friend Jameel Abraham, of BenchCrafted.com, and his brother Fr. John, congratulations for winning the award – it is well deserved!

Disclosure: I am a happy owner of one BenchCrafted tee shirt; I have no commercial or any other interests in BenchCrafted.com. And I love the vises they make.

— Al Navas

Filed Under: Blog, Education, Joinery, Mortise, Sharpening, Tenon, Tutorial Tagged With: , , , , , , ,

Tutorial: hand-cut half-blind dovetails

December 21, 2009 By

Download this video in Quicktime format
(In Windows,  Right-click | Save Link As…)
Duration: 21:41 minutes

One of the readers of the blog recently posted the following Comment to the earlier article on More great drawers:

Could you add ‘Cutting Pins by Hand for Half-Blind Dovetails’ to the list of topics to cover? I fully get how to cut pins and tails for through dovetails, but half-blind pins I can’t seem to wrap my mind around. Is it all chisel work? Is there a sawing technique I don’t know of to cut 80% through the thickness of a board?

Torch, this article and video are my response to your request – perfect timing!

Although today it is considered the hallmark of a woodworking craftsman, the dovetail was not always held in such high esteem. In fact, dovetails used to be buried behind trim, as they were strictly a utilitarian joint; but they were used for their holding strength. Today we make dovetails by hand and with dovetail jigs, to get beautiful results; and they are beautiful!

In this episode I show in detail how to cut one half-blind dovetail on a narrow board. Although I managed to damage the fit on the first attempt, I recovered to shoot the chopping of the pins for this episode in its entirety. In the video I show in high speed the details of chopping the waste, from start to finish:

  1. Very light chiseling at the baseline, to ensure that it stays nice and clean.
  2. Once the baseline is established, more aggressive chopping can take place.
  3. But care must be taken at the half-pins, to prevent splitting of the wood; typically, a narrower chisel, and lighter chisel action are required, or the board will split.
  4. Slight undercutting at the baseline, about 1° to 2°, will result in better and easier fit of the tails in their sockets.
  5. However, too much undercutting will result in a weak joint – as a result, avoid too much undercutting. Practice, practice…
  6. Chop the bulk of the waste with the board supported by the workbench; then place the work piece in the vise, to finish with light paring cuts.
  7. Cut a very small chamfer on the back of the dovetails, to easy entry into their respective sockets in the pins board.

Gary Rogowski is a great advocate of the 5-minute dovetail, a practice session to get ready for the real job of cutting the joinery on a real project. And although the exercise is typically for through dovetails, I believe it applies just as well to half-blind dovetails. In fact, I always do a similar warm-up when I use the Leigh dovetail jig – I never start cutting dovetails cold, regardless the method. Click on this link to see the Inlaid Dovetails Tutorial videos I posted on the blog in March 2008, using the Leigh D4 dovetail jig.

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Filed Under: Blog, Dovetails, Education, Joinery, Tutorial, Video Tagged With: , , , , ,

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