Archive for ◊ July, 2011 ◊

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• Sunday, July 31st, 2011

A jack plane, including this one, is mostly used to true the surfaces of a board and dimension it. It follows coarser tools – the mill saw or, if substantial thickness must be removed, the scrub plane. It is followed by the jointer plane, if needed, and then the smoothing plane or other methods, such as scraping and sanding, to create a finished surface on the wood. Thus, the jack is a fairly rough tool. Yet it is expected to leave a surface without major defects to avoid having to remove too much wood with subsequent tools.

The role of the jack plane dictates its setup. The blade should be sharpened with a moderate camber – a balance between the need to remove wood quickly and leave a decent surface. Judging the proper amount of camber comes with experience, may vary from job to job, and is most easily determined by eye, but it is important to note that a blade that is bedded at a low angle with the bevel up requires more camber, as judged from a 90̊ view, than a blade which is bedded at a higher angle with the bevel-down. Please refer to an earlier post for a full explanation of this.

I prepare the blade with a primary bevel of about 30̊ and a secondary bevel of about 38̊ which, with the Veritas’ 12̊ bed, yields an attack angle of about 50̊. Going significantly higher than this makes the plane simply too hard to push through the wood for this type of work. A smoothing plane is a different matter in this regard. There, fewer and finer shavings are taken, so higher attack angles are practical and may be necessary to avoid tearout.

But wait, isn’t the main point of a BU jack to use high attack angles and prevent tearout on difficult woods? No, not in my opinion. A jack plane does most of its job best when used diagonally across the grain. This makes it easier to accurately remove surface distortions and avoid tearout, obviating high attack angles. I regularly jack plane curly woods diagonally or even nearly perpendicular to the grain.

For the few occasions when a 50̊ attack angle creates significant tearout even with a diagonal stroke, such as with very swirly grain, it is time to employ one of the wonderfully handy advantages of a BU plane. The regular blade can be easily swapped for a toothed blade (sharpened at 40°). This magical blade can manage the most cantankerous of woods.

A further negative consequence of using a blade sharpened with too large an angle (such as 48̊ to produce a 60̊ attack angle) in the BU jack is that it becomes difficult to set the projection of the blade. It is frustratingly difficult to find the middle ground between a shaving that is too light for jack planing and an impractically deep projection, especially if the blade is starting to dull. Imagine trying to pare with a dull chisel sharpened with a 48̊ bevel – you’ll either scrape the wood or dive into it, with little control.

As you near the end of the job with the jack, back off the blade projection to increase accuracy and improve surface quality, thus getting the wood ready for the next stage of preparation.

The next post will discuss securing the board to the bench for jack planing, steps in setting the blade projection, and some particular features of the Veritas BU jack.

Category: Tools and Shop  | 2 Comments
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• Wednesday, July 27th, 2011

I had no specific purpose for this square, but because it looked like it might be a player, I added it to a larger order from Lee Valley Tools. After unpacking the shipment, I nonchalantly placed it aside into the tool well of my workbench.

Over the next few weeks, I found myself picking it up over and over for all sorts of measuring and squaring tasks. This may be the best way to assess the usefulness of a new tool: leave it on the “bench”, like an extra player, casually go to it now and then, and as you become increasingly impressed with its performance, promote it to the starting line up.

Here’s how this tool earned its role as a starter for me. First, it is very handy – small and light. The clean graduations with a sensible height organization and the satin finish make it easy on the eyes. The scales on both legs start at the inner and outer corners and are the same on both faces so I don’t get confused or make errors. I generally prefer to visually split 1/16ths rather than use 1/32-inch gradations but it is helpful to have the 1/32nds on the small legs for fine work.

It works beautifully as a short hook rule, such as to check stock thickness. Also, either leg butts securely against a surface for accurate inside or height measurements. Overall, I like handling the “L” shape more than using a 6-inch rule.

When I evaluated it using a Starrett combination square as the standard, I found it far exceeded Lee Valley’s statement of accuracy. It was straight and square within 0.001″ over its full length.

And, it’s got a 38″ vertical leap and clocks 4.4 in the 40. Just kidding.

As for dislikes, I find the large relief on the inside corner to be unnecessary, and it prevents penciling a line all the way to that corner. (Veritas seems to like this inside corner design. I find it very annoying on their otherwise excellent saddle square.) Also, a flat square like this will be inaccurate if it is held so as to occupy more than one plane when checking a corner. This is not a criticism of this tool but just a reminder of the nature of a flat square and that it does not replace a regular square.

In summary, this little guy is a gamer, a go-to tool in the shop.

[This review is unsolicited and uncompensated.]

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• Monday, July 25th, 2011

From among my habits of work at the bandsaw, here are some that you may find handy.

1- The yellow velcro band placed around the blade is a reminder to tension the blade before work. Starting up the saw with a loose blade is not a happy moment (yes, of course, I’ve made that mistake) but it could be particularly damaging to a carbide-tipped blade. The velcro is placed aside during work so replacing it when the work is done is a reminder to release the blade tension.

2- Much has been written about proper blade tension, but like all tool adjustments, the goal is good performance. The same blade used to saw 8/4 stock will very likely need more tension when it is used for a 10″ resaw. Whether cambering a plane iron, choosing a bevel angle for a chisel, or tensioning a bandsaw blade, it always pays to “close the loop” by using feedback from the tool’s performance to confirm or modify the adjustments. Wood density, blade cleanliness, and heat build-up are just a few of the variables that make it unwise to tension the blade without thought. 

3- After installing and tracking a blade and before going to work with it, it’s a good idea to close the doors on the saw, run it for just a few seconds, wait until it stops completely, and then open the doors to check the position of the blade on the wheels and make sure all is OK.

4- It is easier to follow a layout line when it is viewed with both eyes (binocularly). Sometimes the blade guard or the guide bearing assembly will block one eye’s view of the line, depending on where you position your head.

5- When bandsawing freehand, I always think, “Feed the line to the blade teeth.” This is just the opposite of handsawing and I often have to remind myself to maintain the correct mentality at the bandsaw after I’ve been sawing by hand.

6- The push stick (below) has a rare-earth magnet which allows it to be stored within easy reach on the saw’s frame. The hole is a reminder of which end has the magnet. The short saw kerfs at the front end of the stick, which accumulate as it is used, can grip the corner of the wood as the cut nears completion. The stick has a limited life, of course, so the magnet is in a removable cup.

7- Large sawdust particles inevitably accumulate on the lower tire despite the actions of the wheel brush and the wood plate below the lower bearing assembly. A paint scraper held lightly against the tire as the wheel is spun by hand quickly removes the debris. A “synthetic steel wool” pad such as Scotch-Brite can also be used.

8- The variable-pitch, carbide-tip blade from Suffolk Machinery is a big help in resawing. It also is great for preparing leg stock and any other straight sawing of thick stock. Below is a 10 1/2″ wide Claro walnut board from Northwest Timber which I resawed with this blade. One of the many reasons why the bandsaw is so endearing.

I hope some of these tips prove useful in your shop.

Category: Techniques | Tags:  | 2 Comments
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• Friday, July 15th, 2011

Yes, humble poplar. OK, this is not a species that is likely to evoke lust, but it is a good wood to love. It should not be overlooked for a supporting or occasionally major role in high-end work, as well as duty in utilitarian work.

To be clear, the species under discussion is Liriodendron tulipifera,whose common names include yellow poplar, and, with a bit more cachet, tulipwood and tulip poplar. This is distinct from similar woods: aspen and cottonwood (Populus spp.), willow (Salix spp.), and basswood/lime (Tilia spp.).

Friendly, inexpensive poplar is readily available. My local orange-themed home center carries plenty of dry, dressed 3/4″ thick boards, as wide as the 1 x 12’s pictured below, and sometimes thicker stock. At my local hardwood dealer, sound stock up to 16/4 is available because poplar dries easily and with minimal degradation.

Poplar heartwood is usually pale yellowish green after milling but eventually changes to light brown after exposure. Some boards have deep purplish, green, or other color mineral stain streaks in the heartwood. The sapwood is creamy whitish which tends to develop a tinge of tan. I’ve never seen figured poplar but maybe it’s out there somewhere. It is a modest wood that, in my opinion, is best appreciated for what it is. Attempts to stain it to imitate another wood, such as cherry, end up looking lame to my eye. An exception may be when it is dyed black (ebonized) for use as an accent wood.

Below, left to right: aged poplar, fresher heartwood and sapwood.

Poplar, oh, yea, I mean tulipwood, makes a great secondary wood in fine work. It is hard to find quartersawn, but rift grain for drawer parts and panels can be salvaged from wide flatsawn boards, as seen in the photos below. For novice woodworkers – and we’re all beginners to the extent that we explore and learn new skills – poplar is an easygoing wood that can still yield very nice results. It saws, planes, and glues easily. Its fine texture takes paint well.

 

For utility work, such as storage units, and for many shop fixtures and jigs, poplar is usually my first choice. I also use it very often for mock-ups.

Poplar is a fairly stable wood with tangential and radial shrinkage values of 8.2% and 4.6%, respectively, T/R is 1.8, and volumetric shrinkage is 12.7%, making it certainly more stable than sugar maple and the oaks. It is a light wood, having an average density of 0.42, and surface hardness less than walnut and cherry but greater than white pine. It would suffer as a heavy-use table top.

Surprisingly, though, its stiffness (modulus of elasticity) exceeds that of cherry and big-leaf maple, though it is no match for sugar maple or the oaks. In this respect, it is a better choice for bookshelves than pine, which is considerably less stiff. For its density, poplar has good strength in tension perpendicular to the grain, which produces resistance to splitting, about the same as cherry and big-leaf maple, and much better than pine.

For lots of woodworking jobs, poplar deserves consideration. And some love.

Category: Wood | Tags:  | 2 Comments
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• Wednesday, July 13th, 2011

This is really about efficient use of existing space. To actually make more space would involve things such as moving to a new building or knocking down walls – difficult options for most of us. So to make the most of what you’ve got, think beyond the square feet of floor space, look up, and think vertical and volume.

Loving wood as I do, my small shop was getting cluttered with the lovely stuff and I was no longer at ease in my little playground. After a few minutes of sitting on my workbench and staring at the walls, I began to discern where empty vertical space could open up after only minor rearranging.

I installed two inexpensive Portamate wood racks after being reassured by a structural engineer that the wall studs would easily take the 500+ pound loads. Instead of the shorter screws that came with the racks, I used 4″ TimberLok heavy-duty wood screws (and grade 8 hardened washers) since about 1 ½” of the screw length is taken up passing through the brackets and spacers. The top photo shows a rack installed in a small alcove that was previously underutilized.

Because most of my woodworking is not large scale work, most of the wood I have in storage has been crosscut to about 4 feet long or less. However, the capacity to store some long boards for a long time is still necessary. In the photo above, notice the two utility hangers toward the right, near the top of the wall. Without interfering with anything else in the shop, they make use of the space above the door to allow storage of boards 8+ feet long. The Portamate rack has also opened up more space for the scaffold-type rack that is below it (beyond the frame of the photo).

I am once again at ease in my space. This helps clear my mind as I am working and makes the work more pleasant. Ahhh, the shop.

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