I think it would be good to review and make sense of this handy device that was pictured and cited in the previous post.

As you can see from the photo above, this is simply a glue-up of three pieces of flat sawn red oak on a base of plywood. It is 11/16” thick, and about 15” from the screwed-down end point on the left to the opposite end where it is measured. I cross sawed it from a much larger piece. The “long” grain (which is essentially stable) is just 1 1/2”.    

Observe that the glue up is done with pieces in alternating grain orientation to avoid a large curl-shaped change with moisture change. The large amount of exposed end grain allows moisture content and resultant wood movement to change rather quickly with humidity change. Changes of temperature have no significant effect on the wood length. 

Note also that this wood has not been finished. Therefore, reduction in expansion and contraction, depending on the type of finish used in a project, does not affect this device. 

There is a grid of 1/16” gradation on the plywood base at the right end of the red oak. (The grid is actually wider than needed.) A brad in only the plywood meets the bottom side of the oak to prevent it from rolling from the screw hold and dropping down when you pick up the device to look closer. It is stored vertically on the wall using the hole just above screwed end.   

left side:

right side:

The full range of movement, going from the initial full ~30% water content of wood to fully dried in an oven to 0% content, for red oak, is 4.0% radially and 8.6% tangentially. The approximately “flatsawn” wood in this piece would move somewhere between those two numbers, closer to the 8.6%. Let’s say about 7%.

So, if this piece of red oak went from the ~30% wet to oven dry, it would loose about 7% of its length. 15” would become about 14”. Of course, this never happens in the shop.

What if it really went from a humid shop holding it with 13% moisture content to the shop being drier and holding it with 7% moisture content? The 15” board would shrink to about 14 3/4”. You would see that on the gradation at the right end of the gauge.

Does this really happen? Yes, or at least somewhat that. Also, note that wood shrinkage and expansion actually decreases in range over the years. So, you may observe less than you calculate. However, the expansion-contraction issue is real and must be considered in your construction design.

This simple monitor helps keep you aware of this in a rather large but simple example. I highly recommend it for your shop. It is very easy to make!

I have accumulated attachments for several handy items on the wall just behind the right side of my workbench. This allows for quick grabs and returns of very frequently used helpers.

Here they are, left to right, top to bottom:

1. The shop-made tool oiler. I wrote about making this in a 3/29/2009 post:

The Camellia oil gets used on lots of tools every day. It sits in a little box rack screwed to the wall.

7. The handy little brush with bristles cut short. This gets countless uses, such as clearing the cutting edge opening of a hand plane.

We well start from the beginning. 

The edge is made flat, straight, and very smooth at 90°. This can be filed first, though I generally find this unnecessary because all can be readily done with sharpening stones. If you prefer, use a smooth mill file and a piece of wood to hold it square to the scraper edge. 

I start with my 325/45µ DMT diamond stone, using a simple block of wood to keep the scraper edge square to the stone while consistently moving it to different spaces on the stone as you scrape it. 

I do the same next on the 1200/9µ diamond face. Then I finish on the next finer step that I have available: the 8000/~2µ Kuromaku stone. To stop at 1200 is not bad but there is not much extra work to finish finer. Even 4000 is pretty good if that is what you have available. 

Next, the same general process is done to the flat face. Here, however, there is no need to take forever doing the whole surface. Just a short width – say 1/8” or so – needs to be treated to meet with the edge.

The easiest way to do this is the same general method developed by the late master David Charlesworth for the general sharpening step of the back of a blade. He used a thin strip – I like a .020” strip of plastic – under the blade on one side of the stone, while the other side the blade only contacts the stone with a very narrow width. For scrapers, I again use a simple block of wood to keep the edge contacting the stone flat and straight. Thus, only the most outer small fraction of an inch gets sharpened, and it is much less work.

Just like the edge work up, I go through 325, 1200, and 8000. I usually like to use grippy, waterproof gloves for this work on the wetted stones. 

I find that a little bit of back-and-forth between the edge and the side faces cleans things up nice and neat. And now you are done with the hard work!

Next, we will do the burnishing work.

Now let us consider tuning up the hand scraper. Despite what you may have heard, read, or viewed, this is not a difficult task. What makes some demonstrations and discussions confusing is not presenting a simple understanding of exactly what you need to do with the scraper steel. Most demos do not clearly state what the actual task is for each step.

In the next post I will show and discuss the actual tasks being done. In this post, I will state what is done to the scraper metal at each stage. 

First, the sides and the skinny edge must be made flat and smooth. You do this because the steel is not manufactured smooth enough. That is ok. They should also be approximately square to each other. The surfaces should be honed to at least 1000 stone grit. Better is about 4000, even more. 

Second, compression should be applied to the side faces, just near the edges. Push hard on the steel repeatedly. 

Third, the edge itself should be burnished at an angle – to create the hook which is used to cut wood – scraping.  

That’s it. Done. There are variations and alternatives to achieve each step. These steps are not fully repeated for every sharpening. Every three or so sharpenings, however, require going back to some of the earlier steps. 

Coming up, I will show how I do it. There are other equally good methods and helper jigs to achieve the same principles.  

When you see – and understand – what is going on, you can alter the methods and probably come up with some of your own.   

Here are the dozen hand-blade scrapers that I use. In upcoming posts, I will discuss usages, techniques, and how to sharpen them. 

These are all steel in the hardness range of Rc 48 – 52. Most are Lee Valley. Lie-Nielsen and Bahco are similarly very good. Thickness dimensions are inches/mm.

Top photo, left column, top to bottom:

Sizes approximate. Widths vary from initial purchase due to honing wear.   

1.  .020”/.50mm  6” x 2 1/2”

2.  .024”/.60mm  6” x 2”

3.  .024”/.60mm  5” x 2 3/8”

4.  .032”/.80mm  6” x 2 2/8”

Top photo, right column, top to bottom, curved models:

1.  .024”/.60mm  concave-convex

2.  .024”/.60mm  double convex with different radii

3.  .024”/.60mm  gooseneck 

4.  .016”/.40mm  two mini scrapers 1” x 2” (1” parts sharpened)

Here is the simple storage block (4” wide x 3 1/2” long x 1 3/8” high) with angled slots sawn:

In the photo below, are three concave and convex small scraper combinations, 3” to 3 1/2” overall diameter. I find these very handy. I do not recall the brand name.

I store them in the simple thin leather stapled wallet:

So that’s my crew. I have left the cabinet scraper out of the discussion for now. More scraper discussion is on the way, including how to prepare, sharpen, and work with them.

I wrote about this tool a few years ago, having used it for many more years. It is used for scraper sharpening but it is derived from a saw sharpening device detailed in the book: Tage Frid Teaches Woodworking, Book 1, 1979, page 16. My design is significantly different and used entirely differently. 

This holder makes scraper care easier and more comfortable. I will show and detail the uses for sharpening and flattening scrapers in future posts. Now let us look at the construction of the holder.

Start with two 8” x 8” pieces of 3/4” plywood, each with a top bevel of 45°. (There is a vertical slot and horizontal rim in each piece of the Frid that are not used in this one.) The two pieces are joined by a pair of metal hinges at the bottom edges. 

At the top of each angled edge is a pair of hardwood jaw ends, each about 3/16” thick, to improve their grip. Note the tiny gap that is largest at the center of the jaws, and also the tiny gap at the lower edge of the jaws. These improve the grab contact of a scraper by the jaws.

To tighten them closed, the jaws have two 5/16” button head screws (using free holes), washers, and star nobs that are placed 6” from the bottom and 2” in from each side.  

Attached to the inner jaw is a 14” long piece from a good 2 x 4, trimmed to 3 1/4” wide, with the top planed smooth and flat. The attachment is 4” from the bottom of the jaws and centered. Use three strong hex head screws and washers.

Now let’s see how it is securely held in the tail vise of the workbench. Attached with wood screws at the inner end of the 14” rod is a piece of sturdy 1/2” plywood. It is a trace less than 3 1/4” wide. For length, you want about 1” available to reach below the full thickness at this area of the bench’s tail vice. 4 1/2” long works well for my workbench.

Now, use a direct way (hold it, then clamp it?) to mark where to screw on a horizontal “hook piece” of hardwood about 7/8” tall x 3/4” wide x 3” long. (See the right side of the top photo.) This hooks under the work bench construction.

Finally, screw on a piece of hardwood to extend outward of each side (see the next two photos below), about 5 1/2” long  x 7/8” wide x 3/4” thick, to the top of the 14” rod about 1/2” behind the front of the workbench.

Here it is entirely gripped by the workbench and the bench’s tail vise:

One more thing. Note the three 5/8” diameter x 3/4” deep holes on the platform area. These allow wooden pegs to prevent sliding for burnishing scrapers flat. The center hole is to work with cabinet scraper blades.

This construction makes the vise helpful and strong for burnishing a scraper. It is well held by the workbench. It also has a convenient area for flattening, avoiding medal debris on the workbench. The structure is not difficult to make.

More to come on the topics of scrapers and scraping them.

I enjoyed some instruction classes in the mid-1980s by the late, great Tage Frid at the old Woodcraft store at 313 Montvale Avenue in Woburn, Massachusetts. 

That store then was still the only Woodcraft, having moved north from Boston in 1968. Woodcraft started as a one-room shop in Boston’s North End in 1928 and later expanded. Around 1990, the company started to expand nationally. Much later, the Woburn store moved to its current location, also in Woburn. Woodcraft is now 67 stores nationwide. 

It was at the original Woburn store more than 40 years ago where I bought my Ulmia workbench that I still use. From then, I no longer had to use my own rigs. I had built my first bench in 1971. Before that, the first bench I used was inherited from my grandfather.

Now back to the main topic!